Wikipedia:Featured article candidates/Ceres (dwarf planet)/archive1

The following is an archived discussion of a featured article nomination. Please do not modify it. Subsequent comments should be made on the article's talk page or in Wikipedia talk:Featured article candidates. No further edits should be made to this page.

The article was archived by Gog the Mild via FACBot (talk) 1 October 2021 [1].

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Ceres (dwarf planet)

Nominator(s): Serendi^podous 14:37, 9 August 2021 (UTC)

This article is about the largest asteroid between Mars and Jupiter. Serendi^podous 14:37, 9 August 2021 (UTC)

Procedural note -- Hi Serendi, I see a Peer Review is open for this article and we don't allow FACs and PRs to run simultaneously; if you want this FAC to remain open pls close the PR now. Cheers, Ian Rose (talk) 15:49, 9 August 2021 (UTC)

Jens (support)

• Great to see an astronomy article again, I was missing that. I try to throw some comments in soon. In the mean time, please make sure that everything is sourced (there should be inline citation behind every paragraph in the main text; this is not always the case). --Jens Lallensack (talk) 20:17, 11 August 2021 (UTC)

Are you saying we should cite the lead? The only other uncited paragraph is the single line introducing the three and two layer models; I tried to fix that by making the full stop into a colon, but that got marked in a PR. Serendi^podous 21:09, 11 August 2021 (UTC)

No, not the lead, I am referring to the body. It looks like most of the sentences without citations are merely explanations/rewordings of stuff mentioned earlier (still, I think the respective citation should appear at the end of the paragraph to cover those sentences as well). And I think that, apart from the layer models, this one also needs a citation in any case: Bodies that met the first proposed definition but not the second, such as Ceres, were instead classified as dwarf planets. --Jens Lallensack (talk) 21:46, 11 August 2021 (UTC)

• The first asteroid discovered – I think this needs to be better explained since you previously state it is a dwarf planet.
• The old astronomical symbol of Ceres is a sickle, ⟨⚳⟩ – maybe make the connection to the goddess of agriculture?
• The lead is a bit short and leaves many open questions. What does the name mean? And then: "It was originally considered a planet, but was reclassified as an asteroid in the 1850s after over 20 other objects in similar orbits were discovered. – so why it is a dwarf planet now? I think the lead needs to be improved to properly summarise the article.
• less-dense – should it be "less dense"?

No. Attributive phrases are hyphenated. It's not a lesser amount of dense crust, but a crust that is less dense. — kwami (talk) 01:21, 16 August 2021 (UTC)

• 30 percent ice – be consistent, either use "percent" or % (I would opt for the latter). --Jens Lallensack (talk) 22:53, 11 August 2021 (UTC)

Resolved I think. Serendi^podous 10:34, 12 August 2021 (UTC)

• I recommend to reply to each individual reviewer or coordinator queries (a brief "done" is sufficient). This way, one can easily see that points have been addressed, and this may give you more reviews more quickly.

Will do.

• Theoretical astronomer Johannes Kepler had already noticed the gap between Mars and Jupiter in 1596 – This sentence doesn't make sense at this position in the text, because the reader can't know which gap it is talking about (there is obviously a gab between all planets). The principle should first be explained; maybe switch this sentence with the next?

Good pont.

• Monatliche Correspondenz – Maybe explain what this is and why it is significant? (as you don't give the journals elsewhere).

Done.

• pronunciation),[32] In keeping – either needs a dot or "In" needs to be lower case.

done

• Ceres was once thought to be a member of an asteroid family. – Here I think we already want to know which asteroid family.

done

• Ceres is in a near-1:1 mean-motion orbital resonance with Pallas – I fear this is not accessible enough for the general public. Maybe an explanation could be added? Maybe start the paragraph with a sentence explaining what a resonance is.

done.

• cold traps – I think you need to link to Cold trap (astronomy), not to the technical device. --Jens Lallensack (talk) 22:23, 13 August 2021 (UTC)

done. Serendi^podous 23:02, 13 August 2021 (UTC)

• It has been classified both as a C-type asteroid – I think you should state what C-type asteroids are. done
• In July 2018, NASA released a comparison of physical features found on Ceres with similar ones present on Earth.[60] – Yeah, but what were the results? What are the implications? This sentence, as it currently is, is solely historical, in the section about geology.done
• Ceres is the smallest object likely to be in hydrostatic equilibrium – is this consensus? There seem to be at least some researchers arguing that Enceladus is in hydrostatic equilibrium, which is much smaller?

Not according the the Enceladus article. This is a battle I don't intend to fight. If you want to go into the finer details, I am sure User:Kwamikagami can fill you in. This is his obsession. Serendi^podous 23:51, 15 August 2021 (UTC)

Last I heard, Enceladus had an HE shape for a different rotational period, indicating that it's frozen out of HE. But there've been a lot of measurements of Enceladus since then, so that conclusion might be dated. A lot of refs use circular reasoning with these kinds of statements, though, so we need to be a bit careful. Better IMO to rely on sources dedicated to the question, rather than passing comments in articles reporting on something else. — kwami (talk) 01:21, 16 August 2021 (UTC)

I just think that, if you are not sure that this is consensus (the Enceladus article seems to indicate that Porco et al. (2006) considered this possibility), than you need to formulate the sentence more carefully. Because at the moment, it implies that this is the consensus. --Jens Lallensack (talk) 07:17, 16 August 2021 (UTC)

We should perhaps keep in mind that actual hydrostatic equilibrium is stricter than what the IAU planet and dwarf-planet definitions call hydrostatic equilibrium (i.e. "nearly round"). It has to be, because IAU says explicitly that Mercury is a planet, but it is not in HE. :) So one might want to check the context to see what researchers claiming HE for Enceladus mean. Double sharp (talk) 16:44, 18 August 2021 (UTC)

• The surface of Ceres is "remarkably" homogeneous on a global scale – why "remarkably" in quotation marks? done

I believe that was because the word "remarkably" was used by the source. Without the quotes, it might sound like we're making a POV judgement as to what is remarkable. — kwami (talk) 01:21, 16 August 2021 (UTC)

• Another large-scale variation is found in three large shallow basins (planitia) with degraded rims; these may be eroded craters, and two of the three have higher than average ammonium concentrations – I can't follow here, why is the anomaly restricted to three basins? done
• The water ocean that is thought to have existed early in Ceres's history – This water ocean was not mentioned before, but "The" somehow indicates it was. Can it be properly introduced? done
• Studies by the Hubble Space Telescope – it must be humans doing the study, not the telescope. Reword? done
• a dark spot on its surface, which was nicknamed "Piazzi" – the spot seems to be white on the provided image; explain in the image caption why this is? done
• and thus composed more of rock than ice – "comprised"?

Ugh. No. "Composed of" not "comprised of". Serendi^podous 23:51, 15 August 2021 (UTC)

Yes, I didn't saw the "of". --Jens Lallensack (talk) 07:17, 16 August 2021 (UTC)

• A later computer simulation has suggested – later than what? done
• Section "craters" has mainly history, but very little current knowledge. Maybe at least list the largest craters and interesting bits that might come with them? done
• spots to the east - Vinalia Faculae. – can we make a proper sentence out of this, the dash seems to be misused? done
• the secondary bright spot – what secondary bright spot, and what does that mean? Was not mentioned earlier, should be clearer. done --Jens Lallensack (talk) 21:47, 15 August 2021 (UTC)
• Maybe include a "see also" or "main article" tag to the article Bright spots on Ceres in the section cyrovolcanism? Otherwise it is difficult to find this article. done
• Link the different craters to their article. done (but they don't appear to have articles)

The article is Kerwan (crater). And I think there was another crater which was not linked, I don't remember where it was. You can see the existing crater articles in the expandable navigation template at the bottom of the article. --Jens Lallensack (talk) 11:59, 17 August 2021 (UTC)

• 11 recognizable surface features, the natures of which were then undetermined.[11][69] One of these features corresponds to the "Piazzi" feature observed earlier. – I still don't understand what the Piazzi feature actually is. Dawn must have settled this dispute?

See comment below. Serendi^podous 11:22, 17 August 2021 (UTC)

• irradiation – should be linked or explained done
• most of the planet's surface is extremely rich in carbon, with approximately 20% carbon by mass in its near surface – "Its" already refers to the surface, so this needs reformulation I think. Maybe combine both statements? done
• Can anything be said about the origin of the boulders? How do they form? done
• The active geology of Ceres is driven by ice and brines, with an overall salinity of around 5%. – The overal salinity of what? Of Ceres, the ice, or the brines? done
• The fact that the surface has preserved craters smaller than 300 km (190 mi) in diameter indicate that the outermost layer of Ceres is on the order of 1000 times stronger than water ice. – Not sure if I understand correctly: The presence of small craters mean that the outermost layer was strong? And if there would be a larger crater it would indicate it was weak? This does not make immediate sense to me, maybe explain better.

The source doesn't specify. I would assume because smaller craters on a weaker crust would have relaxed, deformed, or eroded away. Serendi^podous 13:47, 17 August 2021 (UTC)

• As of 2021, two competing models for Ceres's interior, a 2-layer and a 3-layer model, not counting a possible small metallic core, are proposed. – Needs source (a general overview from 2021 would be best). If you can't source the 2021, I would remove that year, because the reader assumes that a source from that year was used. done
• mantle – link at first mention, not in the middle of the article done
• rock (mud) – but mud is not rock. That would be mudstone. done
• kilometre – be consistent throughout the article with abbreviating units (usually you use km) and spelling (kilometre is British English, but elsewhere you tend to use American English). done
• one of the Classical symbols of the goddess Ceres – why is "Classical" capitalised? done
• It is unknown if it contains a rocky or metallic core, – recommend to replace "it" with Ceres for clarity, as "it" could also refer to the mantle. done
• link porosity done
• densities of the core and mantle/crust to be 2.46–2.90 and 1.68–1.95 g/cm3 – respectively? done
• It is unknown if it contains a rocky or metallic core, – does it mean the mantle is the core, or is this about a fourth "layer" within the mantle? done
• It is not possible to tell if Ceres' deep interior contains liquid or a core of dense material rich in metal – a very similar sentence about the core (metallic vs rock) was already given. Combine the two maybe? replaced --Jens Lallensack (talk) 20:47, 16 August 2021 (UTC)
• Hi Serendipodous, have you addressed all of Jens' comments? If so, could you ping them? Thanks. Gog the Mild (talk) 13:28, 31 August 2021 (UTC)

@Jens Lallensack: I don't think I need to ping all of them...Serendi^podous 18:51, 31 August 2021 (UTC)

Hi Jens, du you have more to come on this? Or are you in a position to either support or oppose? Obviously it is not obligatory to do either. Thanks. Gog the Mild (talk) 12:04, 2 September 2021 (UTC)

Hi @Gog the Mild: I was very occupied in real life, but should have time now to finish it. At the moment, I cannot yet support as I still encounter too many issues. It might be close though. --Jens Lallensack (talk) 18:55, 2 September 2021 (UTC)

No worries Jens. And don't feel unduly rushed. It had been a while since your last comment, so I thought I would just check up. Gog the Mild (talk) 19:27, 2 September 2021 (UTC)

• In 2017, Dawn confirmed that Ceres has a transient atmosphere that appears to be linked to solar activity. Ice on Ceres can sublimate when energetic particles from the Sun hit exposed ice within craters.[105] – It is not obvious at first how these two sentences are linked to each other. Maybe make a single sentence out of it (I think it can be slightly shortened if needed)?done
• In 2017, Dawn confirmed that Ceres has a transient atmosphere that appears to be linked to solar activity. Ice on Ceres can sublimate when energetic particles from the Sun hit exposed ice within craters.[105] – I think this belongs with the previous paragraph, I do not see why it has to be a paragraph on its own, and it's very short. done
• Ceres is a surviving protoplanet that formed 4.56 billion years ago, the only one surviving in the inner Solar System – two times "surviving" is redundant.done
• the only one surviving in the inner Solar System, with the rest either merging to form terrestrial planets or being ejected from the Solar System by Jupiter – so ejection from the inner Solar System to the outer Solar System is not a possibility?

The source uses "ejected from the system", presumably the Solar System. Serendi^podous 21:25, 2 September 2021 (UTC)

• with a formation in the asteroid belt – better "within"?done
• The discovery of ammonia salts in Occator crater supports an origin in the outer Solar System. – Could do with a brief explanation. Why do support such an origin?done
• and ammonia salts are more likely to be native to the surface – again, without explanation difficult to follow and comprehend. How can we tell they are possibly native to the surface? --Jens Lallensack (talk) 18:55, 2 September 2021 (UTC)done
• The geological evolution of Ceres was dependent on – does that mean that the geological evolution is not an ongoing process anymore? Or should it be "early geological evolution"?done
• Ceres's relatively warm surface temperature implies that any of the resulting ice on its surface would have gradually sublimated – earlier it was stated that the sublimation was likely due to solar radiation? done
• water volcanism – what is the difference to "cryovolcanism", the term that was used earlier?done
• suggesting that viscous relaxation, water volcanism and tectonics may have erased older geological features – already mentioned in the section "craters", although there only the viscuous relaxation was presented as the most likely explanation.

It is still relevant to that section. Serendi^podous 02:23, 3 September 2021 (UTC)

• There are significant amounts of water ice in its crust.[64] – Seems to be misplaced, was already mentioned several times before, and is too unspecific (how much is "significant"?). --Jens Lallensack (talk) 20:02, 2 September 2021 (UTC)done
• Hi Jens Lallensack, are you in a position yet to either support or oppose this nomination? Obviously, neither are obligatory. Gog the Mild (talk) 15:33, 5 September 2021 (UTC)

Sorry for the delay again, my last comments below. Looking ok now. --Jens Lallensack (talk) 18:24, 5 September 2021 (UTC)

• On 13 November, 1984, an occultation of a star by Ceres observed in Mexico, Florida and across the Caribbean. – verb missing? And I feel it might be good to add which star it was. At least you give this information for the 22 December, 2012 event. For the latter, you also provide magnitude; it would be consistent to provide this for both (or none).done
• Keck telescope should be liked at first mention (currently linked at second mention). Also, the linked article states that The W. M. Keck Observatory is a two-telescope astronomical observatory, so if you are referring to the Keck telescope, which do you mean? If you mean both, than better go with "Keck observatory"?done
• Later near-infrared images – I think you introduced this before. If so, it should refer to that: "The 2012 near-infrared images …"done
• Visible-light Hubble Space Telescope – Same goes here. done.k
• adaptive optics – only link at first mention.done
• Link Dantu to Dantu (crater)done
• Section "Dawn mission" – include a "main article" tag?done
• "Dawn" should be linked the first time it appears in the main text.done --Jens Lallensack (talk) 18:24, 5 September 2021 (UTC)
• Why is On 22 December, 2012, Ceres occulted the star TYC 1865-00446-1 over parts of Japan, Russia, and China.[117] a separate one-sentence paragraph, when the mention of the earlier occultation is not? done. --Jens Lallensack (talk) 20:32, 5 September 2021 (UTC)
• Support – all quibbles addressed. --Jens Lallensack (talk) 06:16, 6 September 2021 (UTC)

Image review

• Suggest adding alt text done.
• Captions that aren't complete sentences shouldn't end in periodsdone.
• File:Ceres_-_RC3_-_Haulani_Crater_(22381131691)_(cropped).jpg: what aspect of this image is CC-licensed? all of them.

• Then what is PD? Nikkimaria (talk) 19:40, 14 August 2021 (UTC)

See the comment at the bottom. Serendi^podous 20:31, 14 August 2021 (UTC)

What we need to clarify is what aspect of the work is PD versus what is CC. For example, did the uploader edit the originally PD source? What was changed? Nikkimaria (talk) 01:02, 15 August 2021 (UTC)

All he did was trim the black from the edges. And what does it matter? PD or CC it still qualifies. Serendi^podous 01:15, 15 August 2021 (UTC)

Either would qualify; if we're using both, we need to be clear on how they interact. Nikkimaria (talk) 12:52, 15 August 2021 (UTC)

• File:Giuseppe_Piazzi.jpg: when and where was this first published? 1808, in Italy presumably.

• In what form was it published? Nikkimaria (talk) 19:40, 14 August 2021 (UTC)

What do you mean published? It's a painting. If you are referring to the uploader, then see here Serendi^podous 20:31, 14 August 2021 (UTC)

No, I'm referring to the painting - simply being painted doesn't make the work published. See definition here. Nikkimaria (talk) 01:02, 15 August 2021 (UTC)

Did you see the link I provided? The image was taken from that site. Serendi^podous 01:10, 15 August 2021 (UTC)

I did. It does not answer my question about whether the image is correctly tagged. Nikkimaria (talk) 12:52, 15 August 2021 (UTC)

It is now. Serendi^podous 16:09, 15 August 2021 (UTC)

It is not. The work may be hosted on the SI website, but it's not originally an SI work. Nikkimaria (talk) 01:25, 16 August 2021 (UTC)

What are you talking about? The work is from 1808! It's public domain! Serendi^podous 01:32, 16 August 2021 (UTC)

Then we should be able to find an appropriate tag for it. What is the earliest publication of the image that can be confirmed? Nikkimaria (talk) 01:44, 16 August 2021 (UTC)

How would that solve anything? Finding the oldest date for online publication won't determine whether it predates 1923. Serendi^podous 01:47, 16 August 2021 (UTC)

Here is the portrait's entry in the Smithsonian Library. It clearly says the portrait is out of copyright. Now can we please put this insanity to rest? Serendi^podous 01:57, 16 August 2021 (UTC)

@Nikkimaria and Serendipodous: Did a quick bit of Googling, and it was published in Monatliche Correspondenz in 1810. Hopefully this link works. Harrias ^{(he/him) • talk} 16:29, 5 September 2021 (UTC)

Thank you. Very much appreciated. I don't know what tag will be required to link the page to the image, but perhaps Nikkimaria does. Serendi^podous 16:35, 5 September 2021 (UTC)

Thanks Harrias! That's perfect. Nikkimaria (talk) 00:55, 6 September 2021 (UTC)

• File:Ceres_Orbit_c.svg: there are two shades of blue here - which is being referred to as "blue" in the caption? Also (and for File:Animation_of_Dawn_trajectory_around_Ceres.gif as well), see MOS:COLOUR done.

• What has been done? Nikkimaria (talk) 19:40, 14 August 2021 (UTC)

I added the meaning of the lighter colors in the descriptions. As for the Dawn trajectory, I have no idea what you want. Serendi^podous 20:31, 14 August 2021 (UTC)

Using only colour to convey meaning presents an accessibility issue - can the accessibility of these images be improved? Nikkimaria (talk) 01:02, 15 August 2021 (UTC)

No, and it doesn't matter. There are only two things in the animation, ergo the image would work just as well in black and white. Serendi^podous 01:15, 15 August 2021 (UTC)

The former includes more than two colours. Nikkimaria (talk) 12:52, 15 August 2021 (UTC)

The orbits are marked, so the colours aren't necessary. Serendi^podous 16:09, 15 August 2021 (UTC)

• Several of the images with a tag based on being "solely created by NASA" credit other entities in addition to NASA. Are they the intellectual property of NASA, or of other entities? Nikkimaria (talk) 16:19, 14 August 2021 (UTC)

NASA material is not protected by copyright. The whole "for all mankind" thing.

To clarify: as per JPL: "Unless otherwise noted, images and video on JPL public web sites (public sites ending with a jpl.nasa.gov address) may be used for any purpose without prior permission, subject to the special cases noted below."

The Dawn mission, from which every single close up image of Ceres has been taken, was a JPL mission, ergo every image taken by Dawn falls under that proviso.

Serendi^podous 16:55, 14 August 2021 (UTC)

• Hi Nikkimaria, how is this one looking? Gog the Mild (talk) 13:31, 31 August 2021 (UTC)

• File:Giuseppe_Piazzi.jpg remains incorrectly tagged; accessibility concerns persist for File:Ceres_Orbit_c.svg. Nikkimaria (talk) 20:56, 31 August 2021 (UTC)

@Nikkimaria: I haven't the faintest idea what you want me to do with the first one; it is directly linked to a page that clearly states it is in the public domain. What else could you possibly want? As to the latter, like I said, the image would still be discernable in black and white, and even so, it doesn't really matter since the only thing of import in the image is Dawn's trajectory, not that it is around Ceres, which is specified everywhere else. Serendi^podous 21:06, 31 August 2021 (UTC)

File:Ceres_Orbit_c.svg does not mention Dawn; are you thinking of the other COLOUR issue mentioned above? As to the first image, as noted, it is not a Smithsonian product and should not be tagged as such. Nikkimaria (talk) 21:09, 31 August 2021 (UTC)

Like I said re: File:Ceres_Orbit_c.svg, every orbit is clearly labelled, so the colours aren't necessary. It would work just as well in black and white. Serendi^podous 21:26, 31 August 2021 (UTC)

@Nikkimaria:: As for the Piazzi image, is is this what you want? Serendi^podous 21:29, 31 August 2021 (UTC)

@Serendipodous:, you may wish to consider rephrasing the query to a volunteer editor giving up their time to help you get this nomination to FA a little more positively if you are hoping for a response. Gog the Mild (talk) 15:36, 5 September 2021 (UTC)

@Gog the Mild:: It's a bit late for that, no? I'll rephrase it but unless we ping another image expert I don't think anything will come of it.Serendi^podous 15:49, 5 September 2021 (UTC)

Are there any image experts willing to answer the questions raised in this review? Becuase I have answered them to the best of my understanding, and still, apparently not to the standards of User:Nikkimaria. I do not know what she wants from me. I would appreciate a second opionion. Thank you. Serendi^podous 15:49, 5 September 2021 (UTC)

@Nikkimaria: I have spent the last four months trying to improve this article. That is all I am trying to do. I have answered your issues to the best of my ability, but I cannot operate in the dark. Your continued refusal to respond to my comments is completely incomprehensible to me. Please respond with what is left for me to do? Serendi^podous 22:38, 12 September 2021 (UTC)

As indicated, I continue to have concerns about the accessibility issues resulting from conveying information through colour alone; I don't agree that information would be adequately conveyed without being able to see the colours. To be absolutely clear, I am not opposing over this issue, so if you choose to ignore it that's up to you. Nikkimaria (talk) 22:46, 12 September 2021 (UTC)

I would love to be able to fix your problem, but I don't know what you want me to do. The only reason the colours exist in the diagram is to distinguish Ceres's orbit. But Ceres's orbit is already marked "Ceres". Other than titling the orbits of the other planets, what else can I do? Serendi^podous 01:57, 13 September 2021 (UTC)

See below. Nikkimaria (talk) 02:25, 13 September 2021 (UTC)

Comment: I have to say, I don't understand the accessibility issue. I added "inclined" to "blue", but you would need to be completely color blind to not be able to distinguish blue from grey, and even then you'd be able to tell which orbit was Ceres'. The blue is merely highlighting. Many more people are blind, which is a much greater accessibility issue. But the blind understand that, and since the information is provided verbally as well as graphically, I would think this img would be more accessible than the maps, which we cannot adequately convey in words.

Serendipodous, I know it's bizarre that a painting uncovered in Pompeii wouldn't be PD for being published before 1923, but that's the wording of the law, at least in the US. But also "unpublished works are under federal copyright for at least the life of the author plus 70 years" (subject to extension). It would appear that visual arts are covered by that. — kwami (talk) 01:42, 13 September 2021 (UTC)

The tagging issue on the painting was resolved above per Harrias' find of an early publication. So no remaining issues there.

WRT accessibility: perhaps it would be helpful to make use of a sim to understand how this is perceived by different users? There are two blue shades in the image, one of which will appear as grey for some types of colour blindness and the other of which basically disappears into the black background for some other types. I appreciate that there are labels, but their size and positioning makes them difficult to read and to interpret. Labelling that was larger and not overlapped with the orbits would be helpful; ditto simplifying the colouring to use only one shade (one which remains visible). Nikkimaria (talk) 02:25, 13 September 2021 (UTC)

I tried Toptal, and the orbit is clearly visible for all 4 types of color blindness. The only problem is with achromatopsia, where the two shades of blue look the same, so you can't distinguish which parts of the Cererian orbit are above and below the ecliptic.

Nikkimaria, what if the lithograph had been first published in 2007? Wouldn't it still be PD because the artist had been dead for more than 70 yrs? — kwami (talk) 02:58, 13 September 2021 (UTC)

I've swapped out the image with one that fits your requirements. Serendi^podous 09:57, 13 September 2021 (UTC)

There seems to be a bit of lorem ipsum near the crossbar. Double sharp (talk) 15:20, 13 September 2021 (UTC)

Swapped out. Serendi^podous 15:47, 13 September 2021 (UTC)

Thank you for increasing the label size; that definitely helps. Nikkimaria (talk) 03:26, 14 September 2021 (UTC)

Kwami

Good to see this article finally brought back up to snuff. It is so much better now! A few minor issues, though.

• The last para in the name section is composed of three unrelated topics (the adjective, the symbol, and the element Cerium). They do not belong in the same paragraph. The FA criteria do not forbid single-sentence paragraphs; they say the number of single-sentence paragraphs should be minimized, since they can inhibit the flow of the text. Like avoiding passives, that's a general rule of thumb, and shouldn't be adhered to too strictly: Cobbling unrelated topics together also inhibits the flow of the text. Better several concise paragraphs that read well than a long meandering one that doesn't. In this case, there's not a lot to say on these topics.

Kwami you are either an editor or a reviewer. You can't be both. One-sentence paragraphs are not allowed as per FA rules. I already went through this. You can complain but if you do you're an editor, not a reviewer. Serendi^podous 09:49, 17 August 2021 (UTC)

Commenting that an article is badly written is part of any FA review, because FA's are supposed to be well-written. Please show where in the FA rules short paras are not allowed. I just showed you where they are. 17:30, 17 August 2021 (UTC)

It doesn't matter. I had to combine short paragraphs to pass GAN. Serendi^podous 17:45, 17 August 2021 (UTC)

It does matter. An article needs to be well-written to pass FAR. And no-one at GAN told you you had to merge unrelated topics into a single paragraph. The GA criteria don't require it either: they just say follow the MOS, which is what I paraphrased above. — kwami (talk) 18:10, 17 August 2021 (UTC)

They told me to when they passed the article for GAN. If that was an issue, it would not have passed. Serendi^podous 19:05, 17 August 2021 (UTC)

I personally try to avoid single-sentence paragraphs whenever possible; and MOS:LINEBREAKS states that "The number of single-sentence paragraphs should be minimized, since they can inhibit the flow of the text. --Jens Lallensack (talk) 19:18, 17 August 2021 (UTC)

I agree. WP:PARAGRAPH says, One-sentence paragraphs are unusually emphatic, and should be used sparingly, and MOS:PARA says, Short paragraphs and single sentences generally do not warrant their own subheading. This is standard practice for writing, not just a WP thing. But "sparingly" doesn't mean zero. When the topics are unrelated, the alternative is to expand on them. One of the topics (adjectival forms) was reduced to a single sentence under GAR; the other, on the element, could easily be expanded, but would be off-topic in this article. I suppose we could move trivia from the footnotes into the main text, but really, trivia doesn't belong in an FA except possibly in a footnote. (The trivia here being that the discoverer of Palladium recalled that he once thought to name it after Ceres, but didn't.) When you have to bend over backwards to accommodate a general guideline, damaging the article in the process, it's better to make an exception. — kwami (talk) 20:04, 17 August 2021 (UTC)

In this particular case, I would go for one paragraph only (as it is in the article right now). It is my feeling that most editors here at FAC would do the same, and featured articles with single-sentence paragraphs are hard to find. I don't think the reader will be confused that these things are discussed within the same paragraph, at least I was not; it read quite fluently and naturally. --Jens Lallensack (talk) 20:18, 17 August 2021 (UTC)

Yes, the reader can follow it. But that's not what a paragraph is for. A paragraph is supposed to contain a coherent topic. We don't just put in a paragraph break after every ten sentences regardless of topic. The MOS doesn't address this; I think they expect us all to have learned how to write a paragraph in highschool.

At paragraph, we say, A paragraph ... is a self-contained unit of discourse in writing dealing with a particular point or idea. According to that definition, what we have here is not a paragraph. It's just a random blob of text. — kwami (talk) 20:32, 17 August 2021 (UTC)

I don't see it that way. To me, the content seems related enough to be discussed in a single paragraph (talking about the second paragraph in the "Name and symbol" section). But lets see what others think. --Jens Lallensack (talk) 20:38, 17 August 2021 (UTC)

In a well-crafted paragraph, the first line introduces the topic of that paragraph. Here the first line has nothing to do with the rest of the paragraph. Yes, all three topics relate to the name, and thus are all belong in the 'name' section. But they don't form a coherent sub-topic within that section. If we're going to merge them together, it would make just as much sense to merge them all into the preceding paragraph, which is also about the name. — kwami (talk) 21:06, 17 August 2021 (UTC)

• Under 'discovery', in the midst of Kepler's, Titius' and Bode's ideas about a missing planet between Mars and Jupiter, there's a comment by Kant about how there shouldn't be a planet there. It's a bit confusing to switch from one POV to the other, and then back again, without any transition. Kant's ideas should probably be at Titius-Bode Law, since in this article we don't go on to detail other people who may have argued that a planet shouldn't be there (that is, the comment on Kant doesn't have an apparent purpose), whereas we do detail how expectations from the Titius-Bode law lead to the discovery of several large asteroids.

I don't know where you're getting that from. Kant says a planet should be there, but isn't. Serendi^podous 09:35, 17 August 2021 (UTC)

In the quote you provided he says, The width between the orbit of Jupiter and Mars is so great that the space enclosed there exceeds the regions of all lower planetary orbits taken together ... that space is worthy of the greatest among all planets, namely, of that which has more mass than all the others together.

In other words, the great gap without planets is due to Jupiter being the greatest of the planets, which is pretty close to modern understanding. If he says somewhere else that there should be a planet there, you should include that in the quotation. — kwami (talk) 17:30, 17 August 2021 (UTC)

That's quite a leap. Or he's simply saying that the great empty space is worthy of a Jupiter-sized planet. Serendi^podous 17:42, 17 August 2021 (UTC)

Sure. But you claim that he says there should be a planet there. He doesn't. If he doesn't say there should be a planet, then the quote doesn't belong here. Not unless you wish to develop the idea into something coherent, in contrast to the Titius-Bode Law. — kwami (talk) 18:10, 17 August 2021 (UTC)

Kwami, have you considered the possibility that you might be wrong? I know that might be difficult for you to accept, but it is nonetheless a possibility. Serendi^podous 18:13, 17 August 2021 (UTC)

Of course I may be wrong, which is why I asked you to include the statement in the quote if Kant did indeed make it.

Unless you mean that I can't parse the quote. That's also a possibility. But if the quote is so obscurely worded that I can't follow it, it's likely that other readers won't be able to follow it either, and so should be removed or replaced for that reason. One of the FA criteria is that an article be clearly written, and if Kant is saying what you interpret him to be saying, this section is not clearly written. — kwami (talk) 18:55, 17 August 2021 (UTC)

OK I admit. I was wrong there. Bad eyesight. Serendi^podous 19:26, 17 August 2021 (UTC)

Michael Hoskin agrees with Kwami's interpretation, saying "In the middle of the eighteenth century Immanuel Kant also sees a dynamical justification for the gap in the great mass of Jupiter".

Incidentally, Johann Heinrich Lambert is even more quotable here (and Hoskin quotes him). "And who knows whether already planets are missing which have departed from the vast space between Mars and Jupiter? Does it then hold of celestial bodies as well as of the Earth, that the stronger chafe the weaker, and are Jupiter and Saturn destined to plunder forever?" Which, in its inclusion of Saturn, sounds even more prescient. Double sharp (talk) 08:38, 19 August 2021 (UTC)

• "Three large shallow basins ... form much of Ceres's lowlands" -- Ceres' lowlands are not defined or described, as they are for the Moon, Mars or Venus, so the reader won't know what this means. How much of Ceres do the lowlands cover? The ref never uses the term; for all I can tell, the planitia are the lowlands. Maybe reword to 'low-lying basins' or something else closer to the ref? (Also, if the planitia have been named since 2018, it might be worth naming them here. One of them is presumably Vendimia)

Rephrased. According to [this map], a low region in the southeast is not a planitia. Also it seems to date Vendimia is the only named one. Serendi^podous 13:13, 17 August 2021 (UTC)

Give the size of Vendimia? We give the size of Kerwan and note the paucity of large craters; I at least would want to know how much larger than the others Vendimia is, and how large it is compared to Ceres. — kwami (talk) 17:37, 17 August 2021 (UTC)

Size added. Serendi^podous 17:54, 17 August 2021 (UTC)

(edit conflict) Still OR. You're interpreting the map yourself, rather than reporting RS's. Indeed, on that page they say, the concentration of domes in Ceres's topographically low regions may provide a clue to their origin. These low regions may be of impact origin. If the low regions are impact features, then it's confusing to say that "much" of the lowest-lying terrain comprises the basins. Better to be agnostic and simply speak of low-lying basins. — kwami (talk) 18:10, 17 August 2021 (UTC)

• "The largest crater on Ceres, Kerwan Basin" -- this contradicts the idea in the next para that Planitia A, B and C are degraded craters, but the discrepancy is ignored. Note that the article on the "missing large craters" of Ceres is a couple years older than the article on the planitia potentially being large craters, giving the authors only a fraction of the time to have evaluated the Dawn data, something the casual reader won't notice.

changed to "largest confirmed crater." Serendi^podous 12:18, 17 August 2021 (UTC)

• "One of these features corresponds to the "Piazzi" feature observed earlier." By now we presumably know what Piazzi was, so it would be satisfying to have the resolution explained here. It would also be nice to identify the two dark Keck features and at least a short comment on whether the 11 Hubble features have been identified with features imaged by Dawn.

See comment below. Serendi^podous 11:22, 17 August 2021 (UTC)

• "A 2017 computer simulation suggested that there were originally as many as 22 cryovolcanoes on Ceres that are now unrecognisable due to viscous relaxation" -- I can't find that number in the source. From the wording, it sounds like Ceres started off with 22 cryovolcanoes and only one of them remains (that is, that if Dawn had visited back then, it would've imaged approx. 22 cryovolcanos on the surface), when what I suspect they meant is that there could have been a series of as many as 22 over the course of Ceres' history, like the sinking seamounts of the Hawaiian island chain. If I've misread and our refs do say that there could've been larger numbers of cryovolcanoes at any one time in Ceres' past, it would be good to make that explicit.

Fixed. Serendi^podous 11:22, 17 August 2021 (UTC)

Still OR. They say there may be as many as 32 today, but excluded 10 because they were too degraded to be useful. Also, they don't give an estimate of how many there may have been originally, but imply many more, so the number 22 is doubly wrong. And the wording still says that Ceres started off with <= 22 cryovolcanoes, and that those same 22 have risen and fallen repeatedly over history -- I'm not seeing anything in the ref about cryovolcanoes being resurrected. Also, the oldest estimate is 500Ma, and they're estimating for the last Gy. There is no mention at all that I can see as to what was "originally" on Ceres.

Changed "repeatedly" to "sequentially". Serendi^podous 18:17, 17 August 2021 (UTC)

Also, the models don't suggest that one cryovolcano necessarily forms every 50My, but that that would be the average over the past Gy. They weren't able to determine if the rate has changed over time. The way we word it, we imply that the rate has remained constant.

Fixed. Serendi^podous 19:44, 17 August 2021 (UTC)

I may have missed it (trying to juggle multiple points), but do we say that the ice was partially rather than fully melted, and give an estimate of the %age of ice in the cryovolcanoes relative to the crust?

Given that it used to be thought that Ahuna was the only remaining cryovolcano, we might want to mention Yamor as another, that Ahuna is prominent because it's young, while Yamor has been preserved because it's near the pole and cold, and that a couple dozen suspected others are degraded. — kwami (talk) 18:10, 17 August 2021 (UTC)

added. Serendi^podous 19:44, 17 August 2021 (UTC)

• "The old astronomical symbol of Ceres ..." -- perhaps a comment that the symbol is still occasionally seen, though usually decorative? E.g. this NASA/JPL poster uses it. (Though they also use symbols for Eris, Haumea and Makemake, as public-outreach rather than a reflection of astronomical use.)

You seem to have refuted yourself there. Serendi^podous 09:57, 17 August 2021 (UTC)

Yeah, okay. — kwami (talk) 18:10, 17 August 2021 (UTC)

• "Its relatively high gravitational field suggests it is dense, and thus composed more of rock than ice" -- this suggests that it is dense relative to the crust, but the ref in the next para concludes that cryovolcanoes have less rock than the crust. It also concludes that diapirs are unlikely to be sufficient to explain Ahura, contradicting this paragraph.

Quoting the source:

The emplacement of the large Ahuna Mons also seems to be best explained by the diapirism of a slurry of brine and silicate particles that Ruesch et al. (2019a) connect to the top of the mantle. ... Ahuna Mons' unique large gravity anomaly suggests a low ice content (Ruesch et al., 2019a). Based on gravity data analysis, Ruesch et al. (2019a) connect the formation of Ahuna Mons to upwelling of a dense slurry from the mantle.

I don't know what source you're quoting. Serendi^podous 12:25, 18 August 2021 (UTC)

Low ice is the same as high rock. The source in that para says the mtns have low ice / high rock content. The scr for the following para says they have high ice / low rock content (which is why they slump on the order of 100My ~ 1Gy). The discrepancy should at least be noted. — kwami (talk) 01:22, 19 August 2021 (UTC)

I don't know what scr means, Kwami. Can you please just tell me what source you're quoting? Serendi^podous 10:31, 19 August 2021 (UTC)

• "A 2018 computer simulation suggested that as many as 22 cryovolcanoes on Ceres, now unrecognisable due to viscous relaxation, have risen and fallen back sequentially over the course of the last 1.5 billion years." -- I don't see how this is a computer simulation, and the ref doesn't say that any simulation came up with the number 22. It's also not correct to say they're unrecognizable: the ref states that they are potentially recognizable as domes, which are assumed to be degraded cryovolcanoes. It's only older domes (> several 100Ma) that are unrecognizable, with the exception of Yamor. The word "sequentially" is misleading here: there is nothing that is sequential. Also, the 1/50My rate is for the past ~Gy, not the much more precise figure of 1.5Gy, and we should note something about not knowing whether the rate has remained constant. — kwami (talk) 03:04, 18 August 2021 (UTC)

fixed.

I still have probs w the cryovolcanism section. ("Scr" above was a typo for src/source. Sorry.)

"A 2018 computer simulation suggested that cryovolcanoes on Ceres have risen and fallen back ..."

No, they only predict that once formed, they will slump back over periods of several 100My. They don't predict that more will keep rising.

"...over the course of the last 1.5 billion years."

I'm only seeing over ~1Gy. From Sori et al.,

Fig 2 in Sori et al goes back to 1.5-2.5 gyr. Serendi^podous 06:32, 23 August 2021 (UTC)

They also said the can only estimate to an order of magnitude. For us to use the figure 1.5Gy is spuriously precise. It makes it sound like more than 1.4Gy and less than 1.6Gy, or at least more than 1Gy and less than 2Gy. — kwami (talk) 06:54, 23 August 2021 (UTC)

Our results are consistent with a cryovolcanic construct forming, on average, every ~50 Myr over the past ~1 Gyr with an effusion rate of order 104 m3 yr−1. ... Over the past 1 Gyr, the distribution of cryovolcanism as a function of time is not statistically distinguishable from a constant distribution in which a cryovolcano forms every 50 Myr

Where you discuss the planitiae, you might want to summarize from that same para in Sori:

our tests reveal that eruptions are not uniformly distributed over Ceres ... Some domes may be clustered in the site of an ancient impact basin, possibly suggesting a genetic link.

Doesn't specificy which basin. Serendi^podous 07:11, 23 August 2021 (UTC)

"Yamor Mons ... resembles Ahuna Mons despite showing no signs of activity"

That suggests that Ahuna does show signs of activity, but AFAICT it doesn't.

Lack of craters. Serendi^podous 06:32, 23 August 2021 (UTC)

No. Lack of craters only means its young. Does not mean it's active. — kwami (talk) 06:54, 23 August 2021 (UTC)

"Models suggest that one cryovolcano should form on Ceres on average every 50 million years."

If I've got this right, the number of relaxed cryovolcanoes they've identified correspond to 1 every 50My. The models don't predict the quantity that should form.

"Its relatively high gravitational field suggests it is dense, and thus composed more of rock than ice, and that its placement is likely due to diapirism of a slurry of brine and silicate particles from the top of the mantle."

Contradicted in Sori et al. p.947, sourced in the next para:

For the domes to viscously relax at all, they must have average ice content greater than typical Cerean crust, which is relatively immobile at these spatial scales. Such an ice enhancement may be expected if Cerean cryomagma is formed by partial melting, rather than complete melting, of portions of the interior. A maximum ice content of the shallow subsurface of Ceres is 30–40%, implying that the domes are 30–70% ice by volume.

[in the previous sentence: Our FEM flow models imply that the domes thus have a maximum volumetric ice content of 70%] — kwami (talk) 03:59, 23 August 2021 (UTC)

— kwami (talk) 00:08, 17 August 2021 (UTC)

• Issues resolved. I hope. Serendi^podous 07:28, 23 August 2021 (UTC)

Okay, new section, per some comments below:

Due to their small masses and large separations, smaller objects within the asteroid belt rarely fall into gravitatonal resonances with other, larger objects.

It sounds like the smaller bodies have small masses, when they mean both the smaller and the larger bodies have small masses. And anyway, the larger objects fall into resonance with the smaller as well -- the dynamics are mutual. So I'd word it s.t. like,

Due to their small masses and large separations, objects within the asteroid belt rarely fall into gravitatonal resonances with each other.

Then it would make sense that Ceres does, since it's the most massive by far, rather than implying that small bodies don't fall into resonance with Ceres because they're small.

fixed. Serendi^podous 10:41, 26 August 2021 (UTC)

Ceres is in a near-1:1 mean-motion orbital resonance with Pallas (their proper orbital periods differ by 0.2%).

What are the implications? The resonance article gives their mismatch at 0.7°/cycle, for a randomization time of a millennium, so I would think there could be no long-term consequence to this. Is it just coincidence? Evidence of something that happened recently? It would be worth explaining what this means if we know, and admitting ignorance if we don't.

The only evidence I can find for near resonances is Wikipedia pages, none of which adequately cite their claims, but they all say they are coincidental. Serendi^podous 10:41, 26 August 2021 (UTC)

Two potential source regions, designated Piazzi (123°E, 21°N) and Region A (231°E, 23°N), have been visualized in the near infrared as dark areas (Region A also has a bright center)

Should mention that the bright center is the Occator faculae. That ties in with,

A haze periodically appears above Cerealia, supporting the hypothesis that some sort of outgassing or sublimating ice formed the bright spots.

No source I can find makes a direct connection between "region A" and either Occator crater or cerealia facula. Not even the one Wikipedia's article on Occator uses to cite it. Serendi^podous 10:58, 26 August 2021 (UTC)

— kwami (talk) 03:21, 26 August 2021 (UTC)

• Hi Kwamikagami, are you in a position yet to either support or oppose this nomination? Obviously, neither are obligatory. Gog the Mild (talk) 15:37, 5 September 2021 (UTC)

kwami ? Gog the Mild (talk) 17:35, 12 September 2021 (UTC)

Sorry, I haven't had a chance to review the article again, though it seems that my concerns have been addressed. I'll try to get to it today. — kwami (talk) 21:29, 12 September 2021 (UTC)

follow-up

Okay, overall review. I edited trivial things such as choice of preposition and sigfigs in conversions in a few places, rather than bringing them up here; hope you don't mind.

Lead

stronger crust that is at most 30% ice.

30% by volume or by mass?

This makes Ceres the closest cryovolcanic body to the Sun known to date.

Awkward. > closest known or, maybe better, innermost known cryovolcanic body in the Solar system done

History

For many years after the acceptance of heliocentrism, several astronomers

Awkward. 'many years' clashes with 'several astrononmers'. Drop 'for many years', since you detail the timing? done

orbits only conformed to

> 'orbits would only conform to' done

each planet was twice as far from the Sun as the preceding

That's an inaccurate simplification for the inner planets. Each planet is at 4+x, which each value of x is twice the preceding. The actual series is 4, 7, 10 [Earth], 16, 28, 52 .... That is, Bode did not predict that Ceres would be 2x the distance of Mars, but at 7/4 the distance. done

there ought to be another planet with an orbital radius near 2.8 astronomical units

We sould note that the prediction was spot-on, rather than making the reader look it up. (I can see why Bode thought he was vindicated!) done

Many theoreticians, such as Immanuel Kant, pondered whether the gap had been

> 'Other theoreticians, such as Immanuel Kant, pondered whether the gap between Mars and Jupiter had been' done

It has a variant [reversed]⟨⚳⟩, reversed to resemble to ... These symbols were later replaced ...

We should have a reference to the original proposal for the symbol, and an early attestation of any variants. According to Cunningham (2015: 69, 206), Zach (who first recovered Ceres after Piazzi's announcement) came up with the sickle as a symbol for Ceres, and it was apparently independently suggested by Bode in 1802 (Cunningham p.164). But I only see the modern orientation, not the reversed form. Could the reversed form be a modern astrological variant, the way Vesta's symbol is? (I'm not finding anything.) Anyway, we can't say "these symbols" if we can only attest to one of them before the ① convention.

There were several other proposed symbols, e.g. an ear of wheat, detailed in Cunningham, but AFAICT they weren't picked up by anyone and so IMO aren't worth bothering about. Though they would be equivalent in importance to the fn on Palladium being transcribed 'C' for Ceres in a notebook.

I think it would be simpler if you added that. Serendi^podous 12:04, 15 September 2021 (UTC)

done — kwami (talk) 19:17, 15 September 2021 (UTC)

Orbit

Ceres is in a near-1:1 mean-motion orbital resonance with Pallas

Incorrect. The source says "A resonance requires ... This is not the case with Ceres and Pallas".

We still don't say what the significance is of it being almost correct. One I can think of is that it probably gives us a good way to calculate the mass of Pallas. done

Rotation

We should give the accurate info (Dawn results) before the inaccurate info (older Hubble results), assuming we give the inaccurate info at all. I don't see why we would want to, so unless there's some reason to keep, would recommend deleting the Hubble info. done

Geology

Ceres comprises approximately a quarter of the estimated

> 'nearly a third' (31% is much closer to a third than a quarter) done

Ceres is the smallest known dwarf planet, and the only dwarf planet inside

> 'Ceres is the only dwarf planet inside'

According to Alan Stern and colleagues, there are many known DPs that are smaller than Ceres. (If we accept that Ceres "is" a DP, despite it not being clear if it fits the IAU definition, then we can't exclude other purported DPs.) And we go on to note that it's about the size of the dwarf planet Orcus. (It's larger than the nominal value for Orcus.)

Alan Stern is a proven liar so I don't care what he thinks. If we have actually imaged Orcus's disc, that's news to me. Serendi^podous 12:04, 15 September 2021 (UTC)

But Grundy et al. also call Orcus a DP. — kwami (talk) 19:03, 15 September 2021 (UTC)

"Ceres" repeated way too much in this para.

Its surface area is approximately the same as the land area of India or Argentina.

>Its surface area is the size of Argentina, and 85% the size of India.

Since we now know the area with considerable precision, we can be more precise. (It's the size of Argentina to within half a percent, so I think we're safe to say it "is" the size of Argentina.) done

Ceres is the smallest object likely to be in hydrostatic equilibrium, being 600 km (370 mi) smaller and less than half the mass of Saturn's moon Rhea, the next-smallest likely object.

Dated, and should be deleted, now that we're no longer adhering to a strict HE-definition of DPs. Besides, Ceres is quite likely larger than Orcus, and we can't judge Orcus' likelihood of being in HE. done

Composition

Studies using the Hubble Space Telescope reveal that graphite, sulfur, and sulfur dioxide are present on Ceres's surface.

This contradicts another claim in the article,

the two other crucial biogenic elements, sulfur and phosphorus, have proven elusive

The claim that there isn't sulfur is more recent. Did they debunk the Hubble results?

The source is infuriatingly vague, but appears to suggest that Dawn found no sulfur. Serendi^podous 16:30, 15 September 2021 (UTC)

Craters

slowly flattening out earlier impacts.

> larger impacts done

with the eastern hemisphere in particular comparatively lightly cratered

You mean the in the equatorial regions? done

The size frequency of craters of between 20 and 100 km

You mean the size frequency in the polar regions? This is a bit hard to follow. done

Cryovolcanism

It is roughly antipodal to Kerwan

Do we have an age estimate for Kerwan? That article states "The crater is likely to be old relative to the rest of Ceres's surface, as it is overlapped by nearly every other feature in the area," contradicting the claim that it might have triggered Ahuna Mons.

That article is uncited. And this citation says that Kerwan is supoerposed over older craters. Serendi^podous 17:51, 15 September 2021 (UTC)

Okay, I fixed the Kerwan article. — kwami (talk) 19:03, 15 September 2021 (UTC)

cryovolcanoes on Ceres have fallen back

"Fallen back" is odd here. Not sure of an appropriate wording: 'slumped'? 'receded'? Maybe someone else here has a better idea. done

BTW, I created a stub article for Oxo crater so we don't have a red link.

Internal structure

The fact that the surface has preserved craters smaller than 300 km (190 mi) in diameter indicates that the outermost layer of Ceres is on the order of 1000 times stronger than water ice.

This makes no sense. You need strength to maintain large structures, not small ones. Pure water ice can maintain craters up to a size smaller than 300 km. Are you sure it isn't craters as large as 300 km?

No. Larger craters take more time to relax into the surface than smaller ones; ergo the fact that smaller craters are still present means that the surface is still hard enough to preserve them. Serendi^podous 17:43, 15 September 2021 (UTC)

done Because you sounded like you knew what you were talking about, I thought you probably had reason to think that (e.g. the source said as much) and that I was wrong, but I forgot that you actually have very little understanding of the subject. "Preservation of craters <300 km in diameter" is clearly shorthand for the the largest craters being under 300km, so I corrected "craters smaller than 300 km" to "craters almost 300 km". If you insist that small craters degrade faster than large ones, please provide a ref. — kwami (talk) 23:20, 16 September 2021 (UTC)

with the mantle and crust being 70–90 km

Does this mean 'each being' or 'together being'? done

That is, the core, mantle and crust

> 'That is, the core (if it exists), mantle and crust' done

Atmosphere

accelerating electrons from the solar wind regularly

I don't follow what "regularly" means here. done

Origin

with the rest either merging to form terrestrial planets or being ejected from the Solar System by Jupiter.

> Other protoplanets in the inner Solar system either merged to form the terrestrial planets, were broken up, or were ejected by Jupiter

Psyche, for example, is the core of a protoplanet. Do we know all the ones Jupiter ejected escaped from the Solar system, or could some have ended up in the scattered disk?

I'm going by the source. What exactly do you want me to do? Find a source that agrees with you? Serendi^podous 18:25, 15 September 2021 (UTC)

I want the article to be accurate. Psyche and Hygiea show that those are not the only two options. — kwami (talk) 19:06, 15 September 2021 (UTC)

Ceres formed as a centaur

Does the ref use the word 'centaur'? I understand that to mean a transient body that migrated in from the TNO region. Rather, Ceres is supposed to have formed among the giant planets and been knocked inward. I wouldn't call that a 'centaur' unless we have RS to back that up, and then I'd edit the centaur article to reflect this. done

friction from planetesimal accretion,

> impact energy, not friction; drop the comma

Not a fan of Oxford, hm? Done anyway. Serendi^podous 18:25, 15 September 2021 (UTC)

These are thought to have been sufficient to allow Ceres to differentiate into a rocky core and icy mantle soon after its formation

But Ceres is not differentiated into a rocky core and an icy mantle, at least not according to some models. So at best we can say "may have been sufficient".

possibly even a liquid water ocean done

But we don't talk about this as a 'possibly': from the fact we don't find such an ocean we conclude that it was obliterated by impacts, not that it didn't exist. So > 'with a likely liquid-water ocean' done

cryovolcanism may have erased

> 'cryovolcanism erased' (it's already presented as a suggestion, and it's a pretty sure one) done

Habitibility

water with 20% carbon by mass

This is a confusing statement. Water is 0% carbon by mass. done

The likely brine pockets under its surface could provide habitats for life.

IMO this would be better placed near the beginning of the paragraph. Maybe something like:

Although Ceres is not as actively discussed as a potential home for microbial extraterrestrial life as Mars, Europa, Enceladus, or Titan, it is the most water-rich body in the inner Solar System, and the likely brine pockets under its surface could provide habitats for life. There is evidence that its icy mantle was once a subterranean ocean. done

I would delete 'watery' and 'after Earth': we give figures elsewhere that Ceres is substantially more water-rich than Earth. Also, do we have evidence that the mantle was once an ocean? I thought people concluded that any frozen ocean was obliterated by impacts, which is why we don't find it.

I find that difficult to believe. Perhaps as a percentage, but the richness is in absolute terms. Serendi^podous 19:55, 15 September 2021 (UTC)

No, richness is in relative terms. We're talking about the chance of life. A huge dry world may have more kg water than a small, wet world, but the wet world would still be considered more likely to be habitable. — kwami (talk) 20:07, 15 September 2021 (UTC)

Isn't Earth a huge dry world if you consider the whole thing (not just the surface)? Double sharp (talk) 07:50, 16 September 2021 (UTC)

Actually, there's a huge amt of water in Earth's mantle, various estimates but many times the amt in the oceans. But as a %age, yes, not nearly as much as Ceres. — kwami (talk) 19:34, 16 September 2021 (UTC)

Maps

allowing for its entire surface to be mapped.

We should explain then why the south-polar region is missing from the maps. Are more recent maps more complete?

None in true colour, that I know of. Serendi^podous 19:03, 15 September 2021 (UTC)

They don't need to be in true color. The B&W maps are also incomplete. — kwami (talk)

Which is why I included the polar maps. Serendi^podous 20:35, 15 September 2021 (UTC)

Which are incomplete. The large black area at the south pole is not an albedo feature, it's shadow. If you took a photo of the quarter moon, so that half the surface was in shadow and thus not visible in the photograph, it would be misleading to claim that you'd photographed the entire surface of the moon. — kwami (talk)

— kwami (talk) 03:41, 15 September 2021 (UTC)

Final evaluation

Thanks. It looks good overall.

I still have a few objections, a new one in a fix, the others from above:

Neptune, once discovered, was 8 AU closer than the law predicted, leading it to be considered a coincidence.

Not clear if "it" is Neptune or the law. Also, a date for Neptune's discovery would help the reader follow the timeline. done

Still stronger crust that is at most 30% ice (by volume or by mass?) in the lead. done

Still say it is the most water-rich body in the inner Solar System after Earth while also saying that it has 500 times the %age of water that Earth has. done

Still there is evidence that its icy mantle was once a watery subterranean ocean. But this contradicts statements like "the data are consistent with a mantle of hydrated silicates": if it had ever been liquid, all rock would've fallen out. And impacts churning up rock would only go so deep. So at minimum this would suggest that the meaning of "mantle" here is different from "mantle" in the cut-away illustration of the interior. Could we maybe drop the word 'mantle' as ambiguous? done

• I object to saying Ceres is the smallest DP when Orcus is likely smaller by volume, and certainly smaller by mass. Also to denying that Psyche and Hygiea exist. — kwami (talk) 19:54, 15 September 2021 (UTC) done

All such additions would be OR. At the very least WP:SYNTH. Serendi^podous 20:02, 15 September 2021 (UTC)

Then subtract. — kwami (talk) 20:18, 15 September 2021 (UTC)

Why? There are 5 dwarf planets, Ceres is the smallest. Also, you call Psyche the core of a protoplanet, which means, by definition, it isn't a protoplanet.Serendi^podous 20:30, 15 September 2021 (UTC)

Yes, Psyche is just the core of a protoplanet. That's the point! Psyche was neither absorbed by the terrestrial planets nor ejected by Jupiter. — kwami (talk)

But as I said, it is not a protoplanet if it is the core of a protoplanet, anymore than Earth's core is Earth. Serendi^podous 21:29, 15 September 2021 (UTC)

You're making my argument for me. The ones that merged to form terrestrial planets aren't protoplanets anymore either. We're talking about what happened to the inner protoplanets, not whether they still are protoplanets. Some merged to form the terrestrial planets. Some were ejected. A couple remain as recognizable protoplanets. Others remain as something else, disrupted to varying degrees. Psyche retains its core. Other don't even have that. You're effectively claiming that the asteroid belt does not exist. — kwami (talk)

quote: "Other protoplanets in the inner Solar system either merged to form the terrestrial planets, were broken up, or were ejected by Jupiter".

So where's the problem? Psyche was a protoplanet that broke up. Serendi^podous 23:56, 15 September 2021 (UTC)

My apologies, Serendipodous!! I thought you had removed that wording. I must've failed to refresh the page. — kwami (talk)

[ah, you had rejected it. Thanks for the additional ref. — kwami (talk)] done

Well yeah. You were asking me to add uncited information. That was the point. Serendi^podous 14:24, 16 September 2021 (UTC)

No, the point is that when you write something that is wrong, and need additional refs to fix it, you find those additional refs. You don't fight to keep it wrong. You are trying for an FA here, remember? — kwami (talk) 19:07, 16 September 2021 (UTC)

You wanted to count Ceres as a DP, despite RS's casting doubt on that claim, and I conceded on the condition that we follow RS's as to whether a body is a DP. You raised no objections. We have RS's that Orcus is a DP. Therefore it is inaccurate to say that Ceres is the smallest DP.

The IAU is not a reliable source? Serendi^podous 21:29, 15 September 2021 (UTC)

Quit playing stupid. It's childish. — kwami (talk) 21:47, 15 September 2021 (UTC)

I'm not playing stupid Kwami; I've never accepted your position. Just because we've been at odds for 10 years doesn't mean I've changed my mind. Serendi^podous 22:07, 15 September 2021 (UTC)

Your dedication to authority is inappropriate for someone editing scientific articles. We follow RS's. That's in the plural. We have RS's that Orcus is a DP. We have RS's that Orcus is smaller than Ceres. Therefore we contradict RS's if we claim that Ceres is the smallest DP. At best we could say that "some sources claim that Ceres is the smallest DP." But why? It's trivia of no real importance. — kwami (talk)

But you don't have all the reliable sources. Unless you can gather together every reliable source ever published about Orcus and show that every single one of them claims that Orcus is a dwarf planet, you cannot argue that any one source tops the designated authority intended to rule on issues of classification. Serendi^podous 22:49, 15 September 2021 (UTC)

"The designated authority intended to rule on issues of classification" -- once again you demonstrate your fundamental failure to understand how science works.

The IAU is the authority for definitions, names, and assigning credit for discoveries. It rejects any role in determining whether an object is a DP, just as it refuses to rule on whether a feature is a crater or a volcano. That would be unscientific, and the IAU is a scientific body.

If we had to demonstrate everything in this article was consistent with "every single RS", we wouldn't have an article. You make an absolute claim when it contradicts RS's. That is inappropriate not only for a FA, but for any article on WP. — kwami (talk) 23:04, 15 September 2021 (UTC)

So if we found a reliable source that made a credible argument that the Sun was not a star, does that mean we should rewrite the entire article to reflect it? Or would we side with the overwhelming balance of opinion? Serendi^podous 23:56, 15 September 2021 (UTC)

If we had RS's that the Sun did not fit the IAU definition of a star, then yes, that is exactly what we would do. Or we would ignore the IAU definition of a star, which would be analogous to what we decided to do in this article.

Here are some reputable astronomers, some notable enough to have their own WP article, who've published in peer-reviewed journals such as Icarus, Science and the letters of the Royal Astronomical Society, and who accept Orcus as a DP:

• Gonzalo Tancredi, University of Uruguay
• Sofia Favre, Los Molinos Observatory
• Simon Porter, Southwest Research Institute
• Mike Brown, CalTech
• Amy Barr, Planetary Science Institute
• Will Grundy, Lowell Observatory
• Keith Noll, NASA Goddard Space Flight Center
• Marc Buie, Southwest Research Institute
• Megan Schwamb, National Taiwan University
• Henry Roe, Gemini Observatory
• Alex Parker, Southwest Research Institute
• Chad Trujillo, Northern Arizona U
• Denise Stephens, Brigham Young U

Another, David Nesvorný, has had an asteroid named in his honor for his contributions to astronomy.

What is your source? An amateur astronomer who is a contributing online writer for Space.com. So, indeed, I challenge your claim that bureaucratic authority trumps science, especially when the bureaucrats deny they have that authority. — kwami (talk)

I don't have something more formal from the IAU, but in their public-facing material, they note that just because they have recognised five DPs does not mean that there are not more: Q: How many more new dwarf planets are there likely to be? A: There may be dozens or perhaps even more than a hundred waiting to be discovered. Okay, this predates Grundy et al., but there's no way you get that many without at least Orcus. Double sharp (talk) 03:58, 16 September 2021 (UTC)

Nice find.

In case someone here wants to argue that statements by an anonymous IAU staff writer are authoritative and should be taken literally, note that they appear to contradict each other. E.g., there are 5 "accepted" DPs, but 2 "known" plutoids. It also says that "Charon may receive consideration," which at best would seem to be idle speculation since the IAU specifically rejected Charon as a DP. But it does show that the IAU is not maintaining a list of DPs the way it maintains lists of satellites, minor planets and named surface features. — kwami (talk) 04:19, 16 September 2021 (UTC)

Still allowing for its entire surface to be mapped.

You say "there is a complete map of Ceres below the first one!" But all the maps are missing the south-polar region, which is in shadow. I think my addition "apart from some shadowed areas at the poles" is accurate. It's misleading to say that a map is complete when you can't see anything on part of it. The south-polar region, AFAICT, has not been mapped.

Fine. Done. Serendi^podous 22:18, 15 September 2021 (UTC)

I skipped the exploration section yesterday. This is the only remaining section, so I shouldn't be adding any more criticisms.

Observation

keen eyes with 20/20 vision may be able to see it

Is "20/20 vision" sourced? "Keen eyes" implies significantly better than 20/20 vision, which is merely average. (Or maybe not even that? According to visual acuity, "normal" vision is 6/4 (better than 20/15), which is better than 20/20.) But keen vision is not just acuity, which can be fixed with glasses; more important is good night vision. [fixed myself]

showed a spot on its surface, which was nicknamed "Piazzi"

We should clarify that it's a dark spot, which we confirm twice later for both visible and infra-red. [fixed myself]

The caption of File:Ceres Rotation.jpg, which shows a dramatic bright spot, appears to be wrong. It seems to identify it as Piazzi:

Hubble images taken over a span of 2 hours and 20 minutes in 2004, showing the "Piazzi" feature

I changed that to "unidentified". Can we determine what it is?

Since the point of that img was apparently to show Piazzi, an ID that was not supported by the published description of the img, I replaced it with File:Ceres optimized.jpg, which is the best img obtained from Earth. The contrast is still enhanced, but less grossly than in the rotation img, so there are several subtle features (as we describe in the text) rather than a single dramatic feature that cries out for identification. I'll count this as done if there are no objections. — kwami (talk)

Dawn mission

and then down to its final orbit ... for at least three months.

We should update this para now that the mission has been accomplished. We hardly need every date, because those are in the dedicated article, but we should change scheduled to the actual durations, add the unscheduled extended mission (XMO), and note when observations ceased. We hopefully have all the data and sources we need in the Dawn article.

Since everything else has been done, I support FA as soon as the Dawn schedule is updated. — kwami (talk) 03:12, 16 September 2021 (UTC)

kwami, "A few minor issues"! I genuinely LOLed. Gog the Mild (talk) 19:31, 18 September 2021 (UTC)

Piazzi

I have been looking for the final identity of the Piazzi feature for months. Besides being impossible to Google (every article on Ceres is going to mention the word "Piazzi", since he discovered the damn thing), there seems to have been a concerted effort on the part of the Dawn mission team not to mention it. I've assumed the most likely answer, which is that Piazzi is Occator crater, but I haven't been able to confirm it. At this point, I may have to start emailing people. Of course, that wouldn't help if they can't point me to a source. Serendi^podous 09:55, 17 August 2021 (UTC)

Schäfer et al. ([2]) have this: "Recent observations with the Herschel Space Observatory by Küppers et al. (2014) detected H2O in the proximity of Ceres and attributed it to the Piazzi feature and one additional surface feature at 20°N by applying a gas kinetic model." Does that help? --Jens Lallensack (talk) 11:48, 17 August 2021 (UTC)

No. I suppose I could look at a map of Ceres at 20 N and see what features correspond to Piazzi, but that would be OR. Serendi^podous 12:09, 17 August 2021 (UTC)

Plus the statement is ambiguous as to whether both features are at 20 degrees or just the latter. I've written someone, asking for a ref for this and the Keck & Hubble features, can write to others if they don't respond. — kwami (talk) 20:14, 17 August 2021 (UTC)

Piazzi is in the middle of Vendimia Planitia, close to Dantu crater. The coordinates agree nicely with the map provided and this pre-Dawn figure. Looks like the region with Occator was previously just called "Region A". Double sharp (talk) 12:45, 19 August 2021 (UTC)

Thanks for that! Still not perfect; doesn't explain what Piazzi is, but at least it closes the wound. Serendi^podous 15:36, 19 August 2021 (UTC)

It's not uncommon for large features in low-res images to disappear in high-res. Looks like Piazzi isn't a geological feature, but a local deviation in albedo. Same with Region A -- the bright spot may be the faculae, but it doesn't appear as though the surrounding dark area corresponds to anything that's visible close-up. — kwami (talk) 03:44, 26 August 2021 (UTC)

Yes, Olbers Regio comes to mind. Double sharp (talk) 09:29, 26 August 2021 (UTC)

I wonder if the dark ring of Region A might be some sort of compensation for the bright spot in the imaging or processing. — kwami (talk) 20:07, 26 August 2021 (UTC)

Support from Double sharp

If I may point out just a small thing: the map of Ceres' polar regions at the end of the article (File:PIA20126-Ceres-PolarRegions-Dawn-20151023.jpg) has "Ysolo Mons" near the north pole. But this name has since been officially changed to "Yamor Mons" (the other map has it right). (The original name, hilariously, originated from a bit of Wikipedia vandalism.) Double sharp (talk) 12:36, 19 August 2021 (UTC)

Well, far be it from us to shirk responsibility for the chaos we cause. Serendi^podous 15:20, 19 August 2021 (UTC)

The caption solves it, thanks. :) Double sharp (talk) 08:51, 21 August 2021 (UTC)

@Serendipodous: In the "Origin and evolution" section Ceres is called the only surviving protoplanet in the inner Solar System; but aren't Pallas and Vesta also, according to protoplanet?

I read through the whole article and everything else read well and looked fine, so happy to support once this last thing is explained. Double sharp (talk) 05:10, 12 September 2021 (UTC)

Thanks :) Last issue resolved. Serendi^podous 13:24, 12 September 2021 (UTC)

Happy to support then. You're welcome! Double sharp (talk) 13:55, 12 September 2021 (UTC)

Support from Cas Liber

Taking a look now....

'Ferdinandea' was not acceptable to other nations and was dropped. - suggest changing to "The latter (term/name/epitet) was not acceptable to other nations and was dropped. " as you've used the word three times in successive sentences.

Dawn revealed that Ceres has a heavily cratered surface; nevertheless, Ceres possesses fewer large craters than expected --> "Dawn revealed that Ceres has a heavily cratered surface, although there are fewer than expected large craters" - to avoid mentioning "Ceres" in 3 successive sentences

Statistics had suggested Ceres should possess 10 to 15 craters larger than 400 km in diameter; however, to date no craters on Ceres with a diameter larger than 280 km have been detected --> try "Statistics had predicted 10 to 15 craters larger than 400 km in diameter, however none with a diameter larger than 280 km have been detected to date" (trim redundant) - also, anything about how this number was predicted?

link infrared or near infrared

NB:Mining of Ceres is just a redirect after an AfD

Other than that, reads well and on track for FA-hood Cas Liber (talk · contribs) 08:36, 21 August 2021 (UTC)

• done Serendi^podous 18:23, 21 August 2021 (UTC)

Support from Hurricanehink

• The opening sentence links to main belt, which redirects to Asteroid belt. I suggest piping it.
  • So you're OK with "largest asteroid in the asteroid belt"?
    • Perhaps "largest astronomical object in the asteroid belt?" ♫ Hurricanehink (talk) 19:17, 25 August 2021 (UTC)
• "it was reclassified as an asteroid in the 1850s after the discovery of over 20 other objects in similar orbits" - why not give the actual year? 1851?
  • There doesn't seem to have been a precise time. It just happened organically. About the closest I could give you is, sometime between 1853 and 1858.
    • But the article says " As the first such body to be discovered, in 1851 Ceres was given the designation 1 Ceres under the modern system of minor-planet designations." Am I misreading? ♫ Hurricanehink (talk) 19:17, 25 August 2021 (UTC)
    • Good catch. Revised.
• "Despite being closer to Earth than Jupiter, which has been known since antiquity, Ceres's small size means that its apparent magnitude ranges from 6.7 to 9.3, peaking at opposition once during its 15- to 16-month synodic period. Thus even at its brightest, it is too dim to be seen by the naked eye, except under extremely dark skies." - I feel like this could be written in three or four sentences. Otherwise, the "Despite" construct isn't paid off until the second sentence, which could be too complicated for some readers. Maybe just switch the order around? For example - "Even when at its brightest, Ceres is usually too dim to be seen from Earth by the naked eye, except under extremely dark skies. Despite being closer to Earth than Jupiter, which has been known since antiquity, Ceres's small size means that its apparent magnitude ranges from 6.7 to 9.3, peaking at opposition once during its 15- to 16-month synodic period." Even then, I'm not sure that you need to add that Jupiter has been known since antiquity, since the focus is on Ceres.

revised.

• "Its surface features are barely visible even with the most powerful telescopes, and little was known of them until the robotic NASA spacecraft Dawn entered orbit around Ceres on 6 March 2015." - since the lead is fairly short, maybe add some of the information learned from the Dawn mission, considering how important that mission was for the understanding of Ceres.
• "Ceres appears to be partially differentiated into a muddy (ice-rock) mantle/core and a less-dense but stronger crust that is at most 30% ice. " - the word "appears" sticks out to me and reads of some uncertainty. Maybe something like - "Based on observations, scientists believe that Ceres is partially differentiated..." or something.
  • Since that info was found by Dawn, makes sense to credit Dawn there.
• " It probably no longer has an internal ocean of liquid water, but there is brine that can flow through the outer mantle and reach the surface." - similar as the above, the "probably" doesn't sit right with me. Could you explain why the "probably"? Also, this would be a good place to add a bit about possible (however unlikely) habitability, since the lead is on the short side.
  • revised.
• Make sure you round "kilometres" after its first usage.
  • round in what sense?
    • Err, sorry, I meant make sure you abbreviate! ♫ Hurricanehink (talk) 19:20, 25 August 2021 (UTC)
      • Is "km-scale" rather than "kilometre-scale" OK then?
        • That's probably one that can be kept fully spelled out, but the rest of the "kilometres" should be abbreviated, per Wikipedia:Manual_of_Style#Units_of_measurement- In prose, unit names should be given in full if used only a few times but symbols may be used when a unit (especially one with a long name) is used repeatedly after spelling out the first use. ♫ Hurricanehink (talk) 13:46, 26 August 2021 (UTC)
• "As the first such body to be discovered, in 1851 Ceres was given the designation 1 Ceres under the modern system of minor-planet designations." - who decided this? This is a pretty big moment, considering that it's the first, so a bit of history would be good.
  • Again, there was no precise moment when it happened. The first to do so was Benjamin Valtz in 1852, but he didn't use it for Ceres.
• "By the 1860s, the existence of a fundamental difference between asteroids such as Ceres and the major planets was widely accepted, though a precise definition of "planet" was not formulated until 2006,[35] when the debate surrounding Pluto and what constitutes a planet led to Ceres being considered for reclassification as a planet." - can you find a way to re-word so you don't say the word "planet" four times in a sentence?
  • revised.
• "But on 24 August 2006 the assembly adopted the additional requirement that a planet must have "cleared the neighborhood around its orbit". " - poor grammar, starting a sentence with "But"
  • I seem to have revised that without meaning to.
• "Ceres follows an orbit between Mars and Jupiter, within the asteroid belt and closer to the orbit of Mars, with a period of 4.6 Earth years" - what is the "period" mentioned here?
  • revised.
• "Compared to other planets and dwarf planets, Ceres's orbit is moderately though not drastically inclined (i = 10.6° compared to 7° for Mercury and 17° for Pluto) and eccentric (e = 0.08 compared to 0.09 for Mars)." - could you explain this in laymen terms?
  • revised.
• "Orbital resonances, instances in which celestial objects fall into gravitational step with the orbits of other, larger objects, are rare in the asteroid belt, due to the asteroids' small masses and large separations." - this sentence is a bit complicated. I suggest something like "Due to their small masses and large separations, it is rare for asteroids to have orbital resonances, in which celestial objects fall into gravitational step with the orbits of other, larger objects." Not sure if that wording is accurate, but something along those lines is clearer.
  • revised.
• "Ceres is in a near-1:1 mean-motion orbital resonance with Pallas (their proper orbital periods differ by 0.2%)." - any reason for this second linking of orbital resonance?
  • revised.
• "About 0.14% of water molecules released from the surface are expected to end up in the traps, hopping an average of 3 times before escaping or being trapped" - is "hopping" a technical term here?
  • The term used in the article is "a model of ballistic hops".
• "Hubble Space Telescope observations" - maybe specify the year, that it was taken before the Dawn mission?
  • revised. Serendi^podous 20:23, 25 August 2021 (UTC)
• "however, none with a diameter larger than 280 km have been detected to date... the largest confirmed crater on Ceres, Kerwan Basin, is 284 km across..." - uhh, contradiction much?
  • revised
    • But a reader still might be confused by the 284 one being larger than 280 km. Maybe just say "only one with a diamater larger than 280 km?" ♫ Hurricanehink (talk) 13:46, 26 August 2021 (UTC)
• "A 2018 computer simulation suggested that cryovolcanoes on Ceres have fallen back due to viscous relaxation over the course of the last ~billion years. " - can you write out something rather than the informal "~billion"

revised.

• "Vast regions of the surface of Ceres lack any large (>100 m (330 ft)) boulders. " - yikes can you avoid the double parenthesis?
  • revised.
• "In early 2014, the Herschel Space Observatory detected localized (not more than 60 km (37 mi) in diameter) mid-latitude sources of water vapor on Ceres" - again, can you avoid the parenthesis within parenthesis?
  • revised
• "Today, Ceres has become considerably less geologically active" - the "Today" isn't needed
  • revised.
• "In 2014, the Herschel Space Observatory found Ceres to possess a tenuous atmosphere of water vapor." - you mention this under "Observation" and "Atmosphere"
  • removed.

The article isn't in bad shape by any means, but compared to other articles about solar system objects, I feel like it's lacking. I fixed a typo during my review, which suggests that there hasn't been enough eyes. Still, I don't believe my comments will be too difficult to address, so I'll be happy to revisit my review when you address my concerns. ♫ Hurricanehink (talk) 16:51, 25 August 2021 (UTC)

All issues addressed. Serendi^podous 20:46, 25 August 2021 (UTC)

I'm switching to a conditional support. Thanks for addressing my concerns so quickly! I just have two outstanding issues - the km being rounded, and the bit about no craters being larger than 280 km. ♫ Hurricanehink (talk) 13:46, 26 August 2021 (UTC)

Issues addressed. Thanks! :) Serendi^podous 15:31, 26 August 2021 (UTC)

Also, I noticed quite a few km that don't have imperial units, so be sure to convert them. ♫ Hurricanehink (talk) 15:36, 26 August 2021 (UTC)

added. Apropos of nothing, when did this mandatory imperial conversion become standard? It's been 10 years since I did an FAC so I admit there's a bit of a "these kids today", but to me it just feels like a concession to Conservapedia. Serendi^podous 16:41, 26 August 2021 (UTC)

Not sure, but thanks for adding it! I've been writing featured articles for 15 years now, and as an American, I've always used both metric and imperial units in articles, and it's been part of the Manual of Style for as long as I've been editing. Rather than being a concession, adding the units helps make the article accessible to all readers. Thanks for your work in this important article, and I look forward to its return being part of a featured topic :) ♫ Hurricanehink (talk) 17:41, 26 August 2021 (UTC)

@Hurricanehink: I'm a Yank too, but I don't bother with imperial. For an international encyclopedia, IMO we should use international standards. For all those ppl who don't use imperial and find all the parentheticals distracting, wouldn't it be better to use a hover-over conversion? Place your cursor over the metric units, and get a little pop-up with the imperial equivalent? We have a similar problem with pronunciations, where we only make an exception to IPA for Usonians, with an awkward respelling system that doesn't really work very well. Most articles only use IPA. — kwami (talk) 05:18, 14 September 2021 (UTC)

@Kwamikagami: Do you support this nomination, or not? Serendi^podous 12:07, 14 September 2021 (UTC)

I keep meaning to go over it again for a final evaluation, but I haven't been able to get to it. That's not going to hold up approval. — kwami (talk) 14:25, 14 September 2021 (UTC)

Comments by Dudley (support)

• "Despite being closer to Earth than Jupiter, which has been known since antiquity," I doubt you need to say this. Few if any readers interested in the article will not already know these points.
• You say in the lead that Ceres is a dwarf planet, in the infobox likely dwarf planet. This is inconsistent.
• "theoretical astronomer and mystic Johannes Kepler" Your source says that Kepler wrote the Mysterium cosmographicum (Cosmographic Mystery), but does not describe him as a mystic.

OK, what word should I use to describe why he wanted the Solar System to follow a preconceived set of ratios he made up? Serendi^podous 19:48, 2 September 2021 (UTC)

• It is not the role of Wikipedia editors to express personal opinions on how Kepler should be described. We should follow reliable sources and your source does not say he was a mystic. Dudley Miles (talk) 08:18, 5 September 2021 (UTC)

Revised. Serendi^podous 13:57, 5 September 2021 (UTC)

• "an i = 10.6°". I suggest "an orbital inclination (i) of 10.6°" would be clearer.
• "stretched". I would prefer eccentricity.

Another reviewer wanted a word more accessible to the layman. EDIT: subbed with "elongated". Serendi^podous 19:48, 2 September 2021 (UTC)

• "suggesting up to a quarter of its mass is composed of water". Is there a minimum estimate for water composition?
• "Ceres is close to being in hydrostatic equilibrium, and thus to being a dwarf planet". This implies that it is not a dwarf planet, but you say it is.

I say it's a dwarf planet, because it is, officially, by definition. The rest is just Kwamikagami being lawyery. Serendi^podous 19:48, 2 September 2021 (UTC)→

There is nothing official here apart from the IAU definition. A body cannot be "officially" a DP, any more than a stallar object can be "officially" a brown dwarf, because the IAU definition is not "whatever we decide is a DP", but the physical criteria that define the category of DP -- and the IAU has no control of the physical properties of an object. All we can do is follow RS's as to whether it fits the definition. There have been some RS doubts as to whether Ceres fits the definition. I have no idea whether those doubts will stand up to scrutiny. If we find RS's that say those doubts are either spurious or have been addressed, then I'll be fine with saying that Ceres is a DP.

Or, if we find a RS that astronomers have come to ignore the IAU definition and instead follow Stern's rule of thumb, "if it looks like a world, then it's a (dwarf) planet", then after modifying the DP article accordingly I'd be happy with saying Ceres is a DP. It's certainly a "world" in Sterns' sense. — kwami (talk) 20:39, 2 September 2021 (UTC)

Kwami, Wikipedia is not helping anyone by saying that Ceres isn't a dwarf planet. Everyone who is remotely qualified in the required fields says Ceres is dwarf planet. You can disagree, but ultimately you're just crying No true dwarf planet. So work this issue out of your system or stop editing Wikipedia. Serendi^podous 20:51, 2 September 2021 (UTC)

No. We follow RS's on WP. We don't dumb things down because we don't think the reader can handle it. "Everyone who is remotely qualified ... says Ceres is dwarf planet" -- except for those who don't. It would be easier for all of us if Ceres were a DP. But we have a RS saying that's not clear. Until you address the RS issue, you cannot cherry-pick the sources you like and ignore those you don't.

Again, if you can provide a consensus from "everyone who is remotely qualified" that those RS concerns are not relevant / have been resolved, then I'm happy to accept Ceres as a DP. But it's up to you to provide the RS's for your claims. And I'm not going to stop editing because you find the RS requirement onerous. — kwami (talk) 21:18, 2 September 2021 (UTC)

• "graphite, sulfur, and sulfur dioxide are present on Ceres's surface. The former is evidently the result". I think "former" can only be used in selecting from two - with three it is ambiguous. (The reference to "latter two" clarifies, but I think it is still better avoided.)
• "Their maximum age is of 150 million years". Why "of"?
• More to follow. Dudley Miles (talk) 10:57, 2 September 2021 (UTC)

Other issues resolved. Serendi^podous 19:48, 2 September 2021 (UTC)

• "The leaching of water from rock is estimated to yield a salinity of around 5%.". It may just be my ignorance, but I do not understand this. fixed
• "The fact that the surface has preserved craters smaller than 300 km (190 mi) in diameter indicate that the outermost layer" The fact...indicates, not indicate. fixed
• "Gravity measurements from Dawn have generated two competing models for Ceres's interior." This is effectively a sentence which is a heading to the subsections below, which looks odd. I suggest numbering the models 1 and 2 instead of making them subsections. Also, as there are two different two layer models, is that not three models in total? fixed
• What is "admittance modeling"? Could it be linked to Admittance?

No. It is a technique for determining interior structure from gravity and topography. Serendi^podous 12:20, 6 September 2021 (UTC)

• Is there an article it could be linked to explaining? Otherwise I think it needs a note. Dudley Miles (talk) 12:25, 6 September 2021 (UTC)

that link above IS to an article explaining it. Just not in a way that I can express. Serendi^podous 12:27, 6 September 2021 (UTC)

• I should have made clear that I meant a wikilink - or a note in the notes section of the article. I think one or the other is needed as many readers will not understand the term. Dudley Miles (talk) 12:46, 6 September 2021 (UTC)

Given that it's completely irrelevant, it might as well not be there. Serendi^podous 13:20, 6 September 2021 (UTC)

• "Hints of an atmosphere had appeared in early 2014, the Herschel Space Observatory detected localized mid-latitude sources of water vapor on Ceres" This is ungrammatical. Maybe "in early 2014 when the Herschel" fixed.
• "The limited data available was more consistent with cometary-style sublimation". "previously available" would be clearer. fixed.
• "On 13 November 1984, an occultation of the star BD+8°471 by Ceres was observed in Mexico, Florida and across the Caribbean." I do not see how occultations are relevant unless they tell us something about Ceres. fixed.
• "that a massive cryovolcano called Ahuna Mons is the strongest evidence yet for the existence of these mysterious formations". There are two issues with this. 1. You have already referred to Ahuna Mons several times, but you refer to it here as if it has not been previously mentioned. 2. What is meant by "evidence yet for the existence of these mysterious formations"? You seem to be referring to the bright spots, but there is no mystery whether they exist. fixed.Dudley Miles (talk) 11:39, 6 September 2021 (UTC)
• Support. Looks fine now. My only other point is that you should explain why the 22 December 2012 occultation is relevant. Dudley Miles (talk) 15:53, 6 September 2021 (UTC)

Dwarf planet?

Serendipodous has gotten really PO'd over my stance on this issue, fearing it puts FA status in jeopardy, so perhaps this deserves its own section where others can comment.

I don't know whether Ceres is a DP or not. It's certainly referred to as one often enough, including by the IAU (and this years before anyone could actually know). But Serendipodous believes that an object is a DP or not based on whether the IAU announces it to be, not based on whether it actually fits the IAU definition of a DP. That's not how any science works -- defining a category so we have an agreed set of terms does not determine the physical characteristics of any particular body. That's up researchers to determine.

I'm aware of only one RS that addresses the issue of whether Ceres fits the IAU definition of DP. It concludes that there are anomalies that have not been explained. Those issues may now be resolved. There are presumably many other sources that I've never heard of. It may be that other astronomers have rejected those doubts, and that the consensus is that Ceres is a DP. I don't know, and I hardly care, except as a bit of trivia. But I do care that we follow RS's in a FA. — kwami (talk) 02:20, 3 September 2021 (UTC)

The views I express below grew out of the discusion at Talk:List of possible dwarf planets#Mercury.

The most interesting point is that it has been known since 1984 that Mercury is not in HE in the strict sense(!), and yet the IAU didn't see any problem with that when writing its 2006 definition that required HE for planets (and dwarf planets too). This kind of suggests to me that either the term HE is not being understood in a strict sense in the IAU definition, or the definition is just being ignored in favour of the bald list. Now that MESSENGER happened, it's beyond doubt that Mercury is not in HE; the fact that nobody made any noises about it suggests that at least one of my conjectures is correct. (Okay, you could argue that they wouldn't want to demote their planet of study, but even then it could have been spun as "the IAU definition needs work", which didn't happen either.) Even more strongly: you'd think that doubts about Ceres being in HE would be music to the ears of Plutophiles, because one of the strongest counters to Pluto alone as a planet is "what about Ceres" – but no one made a fuss. And even more interestingly, Ortiz had no problem calling Haumea a DP while suggesting that it could not be in HE.

So, the definition of planets and dwarf planets says HE, but no one connects it to those cases. This makes me think that asking for strict HE may, at the very least, be falling into a trap of not getting some unstated context. I remind that the IAU definition of a planet does not define "clearing the neighbourhood" either, and if we were to overlook some context on that, we'd be back to saying Jupiter is not a planet because of trojan asteroids. This could very well be a similar case.

It seems to me safer to use the actual statements. Well, according to their site, Ceres is a dwarf planet. And while I've indeed seen doubts about Ceres being in strict-sense HE, it certainly seems to me that Ceres' status as a DP is not actually questioned by astronomers or planetary scientists. That's actually an even clearer situation than, say, Quaoar (which the IAU does not recognise as a DP, but quite a few serious scientists do, and anyway the IAU admits that there may be more dwarf planets than the five they recognised).

Therefore, I think it's best to call Ceres an unqualified DP, reflecting both the IAU (which names it as one on their pages) and common usage. The fact that it's not in strict HE seems somehow unrelated in actual usage, despite the way the definition is phrased. Calling Ceres only a possible DP, while perhaps reflecting the strict letter of the IAU definition, seems not to follow any actual source. It seems to be the result of original-to-WP interpretation of the IAU definition, and I worry that it overlooks some context that was meant to be understood, just like a reading of the IAU definition that excludes Jupiter for its trojans would. Double sharp (talk) 03:21, 3 September 2021 (UTC)

"Quaoar (which the IAU does not recognise as a DP)" -- the IAU is not in the business of recognizing DPs, so the fact that they don't recognize a body as a DP means nothing at all. Haumea and Makemake were special cases, part of a bureaucratic compromise as to which committees got to review proposed names for which bodies. That decision has nothing to do with the status of any other body, and the IAU even made a provision for Haumea and Makemake turning out not to be DPs.

That quibble aside, I don't have a problem with any of your suggestions in principle. Grundy, Noll & Buie et al. state that Orcus is a DP, even though their research only shows it to be a solid body. If we stuck to fairly recent RS's (Tancredi and Brown are both rather dated), we could say that Haumea, Makemake, Gonggong (per NASA), Ceres, Quaoar and Orcus "are" DP's, as far as we know, and that Salacia and Sedna remain possibilities. The WP articles for those bodies could start with something like "Orcus is a dwarf planet in the Kuiper Belt in resonance with Neptune," with a RS stating that it's a dwarf planet, or that "Salacia is a large trans-Neptunian object and possible dwarf planet." Brown's judgements should probably be removed from leads as being a decade out of date. We also might want to sometimes fudge things a bit by using the word "planetoid". In the body of the article, we could get into why people believe Orcus or whatever to be a DP, but that's no different than saying Hittite is an Indo-European language in the lead and info box and then getting into why people believe that to be true, as well as reporting on minority theories that it's not (e.g. Indo-Hittite). The same of course would be true of Ceres: "Ceres is the largest asteroid and sole dwarf planet in the asteroid belt", with unexplained anomalies in its shape left to the body of the article. Or "Mercury is the smallest planet and the closest to the Sun", with its deviations from HE covered in the text.

Personally, I think that would be a much more practical approach to our articles. The problem we'd run into is that our DP article is a FA, and it strictly follows the IAU definition. It could be that it should be rewritten to follow a more practical definition (a DP is what RS's say is a DP, presenting the IAU as just one of several RS's) or have its FA status reviewed. But we don't want two FA's contradicting each other, with one saying "dwarf planet" is a term of convenience for world-like bodies, and the other saying it's a technical term with a precise definition. As you point out, the reality is that no-one pays much attention to the IAU definition. But for the FA 'dwarf planet' to reflect that reality, we'd need RS's that that is the case. Or, if there's consensus that we devote too much space to finicky definitions, we could gut the DP article, leaving all but a summary of the definition to "IAU definition of a planet", revoke its FA status and merge it with an abbreviated 'list of possible DPs'.

If there are no objections to me removing claims in the DP article than a DP is a category strictly defined by the IAU, so there would be no contradiction if Ceres were promoted to FA, then I have no objection to Serendipodous wording this article the way he wants to. — kwami (talk) 04:45, 4 September 2021 (UTC)

Maybe the DP article should just say that the IAU formalised HE, but scientists use it more loosely (and as an example, we can cite Ortiz saying Haumea is a DP but that it can't be in HE). Actually, it seems not far from that. Even the IAU sometimes talks more loosely: A dwarf planet is an object in orbit around the Sun that is large enough (massive enough) to have its own gravity pull itself into a round (or nearly round) shape. (So, it just needs to be round, and have enough gravity for that to be the cause. No "coincidentally round" objects like Phobos, of course.)

Judging from Google Scholar results, some sources simply call Quaoar a DP, and those that demur still say it's likely. So, maybe "highly likely DP" is the best way to go here. Haumea seems universally called a DP, maybe because the IAU naming it as a presumed one. So I don't think it'd be too different: the IAU five can get called unqualified DPs, and for example Quaoar can be called a highly likely DP. Which is more or less the distinction the tables at dwarf planet already make: the almost-certain candidates are included, but the IAU five are highlighted. More iffy ones like Salacia can then get the "probable" qualifier.

Does Grundy think that not being solid necessarily excludes DP-hood? If you take the HE idea it should, but if you take the idea of shape, then maybe not, right? Couldn't, say, Chaos and Varda still be round even if they aren't solid? Double sharp (talk) 08:16, 4 September 2021 (UTC)

Methone is round under its own gravity. So is any large rubble pile. So yeah, I suspect being solid (in the sense of no interstitial spaces) is sine qua non. As for Grundy et al., yeah, they refer to solid bodies as DPs, but not dark, low-density bodies like G!kun||'homdima.

The site you linked to is 'Astronomy for the Public'. It's dumbed down for public consumption. It would be different if they said "like Vesta or Pallas", or gave some other specific example. For a RS of the IAU's position, we need a formal statement, publication in Icarus or the like.

Anyway, the IAU didn't invent the term. Alan Stern did. So it's really not NPOV to use their definition, which can be explained in detail at 'IAU definition of planet'. I'll start editing the DP article to be more neutral, though it may take a while. Unless you want to -- you might be a better choice, since I've gotten into so many quarrels about this.

I do object to making the IAU the gate-keeper. That's not their role. They didn't claim it and don't want it. If we're not going to follow a strict definition, then we need to follow RS's, which isn't the IAU but the researchers who actually work on these objects. All objects down to Orcus are called DPs by the people who investigate them. I have my doubts, personally, but TRUTH. — kwami (talk) 22:29, 4 September 2021 (UTC)

​ Could I have the quote from Grundy? I didn't remember seeing it, but it's likely I just missed it somehow. And yes, Methone and Phobos rather do make it an obvious requirement.

Is there someone who doubts Sedna? Or is it just following the Grundy et al. study, because its density is unknown? Double sharp (talk) 04:38, 5 September 2021 (UTC)

It's in Grundy et al. (2019) 'Mutual Orbit Orientations of Transneptunian Binaries', Icarus 334: 62–78. Just search 'dwarf'.

I would think everyone would doubt Sedna, unless you're like Stern and accept Proteus. Its estimated size puts it in Grundy et al's transition range, and I wonder how realistic the 10% error bar is on its size. Though if its albedo really is 32%, that suggests resurfacing or at least recent outgassing, which is promising. And if its albedo is below the transition guestimate of 20%, then it would have to be > 1260±100 km, which would also be promising. So yeah, doubt, but not too much. — kwami (talk) 04:53, 5 September 2021 (UTC)

Anyway, since Ceres is now called a DP here as a result of this discussion, I guess that resolves the problem as far as this article goes. Double sharp (talk) 04:40, 5 September 2021 (UTC)

• Hi kwami and thanks for bringing this up. You happy now? Gog the Mild (talk) 15:26, 5 September 2021 (UTC)

I'll be happy if I can make the DP article consistent with this one. I've had edit wars there before, with people insisting that a DP is what the IAU defines it to be, not how astronomers actually use the term. As long as the DP article can say, basically, 'A' is how Stern (who coined the term) uses it; 'B' is how the IAU defines it, which essentially everyone ignores; and 'C D E' are how other astronomers have used it, so that what is or is not a DP is a matter of usage rather than exact definition, then this article is good. But if at DP there is consensus that this article is a FA, it must adhere to the letter of the law, then to be consistent we won't be able to say here than Ceres is a DP, unless someone finds better sources than we currently have. But I don't think there's any reason to hold up FA review for that -- it's a terminological quibble that doesn't have much real effect on this article. This article shouldn't be held hostage to that one. If there are irreconcilable differences between the two, then we'll have to start a broader discussion. But yesterday I made edits that a few years ago would've sparked a furious edit-war, and so far not a peep. So maybe it won't be a problem this time around. — kwami (talk) 06:13, 6 September 2021 (UTC)

Okay, fine to have Ceres presented as a DP without caveat, and will be happy with the article once we make this article consistent with others by removing the specious claim that Ceres is the smallest DP. — kwami (talk) 08:40, 16 September 2021 (UTC)

All I want, all I ever wanted, was an official declaration stating that Orcus is a dwarf planet that was not reliant on the opinions of individual astronomers or planetary scientists. Yes, plenty of astronomers believe that Orcus is a dwarf planet. That is true. Plenty of astronomers also believe Planet Nine exists. That doesn't mean it does. There has to be some authority to represent the standard consensus in the field. The IAU, as far as I can tell, is that authority. Just because they're currently doing a terrible job doesn't mean it's Wikipedia's job to pick up the slack. That's not Wikipedia's job; it's WP:SYNTH. Serendi^podous 09:12, 16 September 2021 (UTC)

"All I want [is] an official declaration" -- you're not going to get one, because that's not science. Reality is not determined by diktat. An official declaration would mean that the IAU had abandoned their definition of a DP. Rather than being a physical definition, it would be an arbitrary, bureaucratic one. That was actually under consideration: Pluto and anything larger would be a 'planet', anything smaller would not -- but it was rejected as arbitrary. They're not going to resurrect something like that without another full meeting of the IAU, and I seriously doubt that's going to happen while this FA is pending. If it does -- if the IAU changes the definition of a DP -- then we can update this article at that time.

"not reliant on the opinions of individual ... scientists" -- but that's how science works.

"Plenty of astronomers also believe Planet Nine exists" -- show me one who has published a peer-reviewed article that identifies a particular object as Planet 9.

"There has to be some authority to represent the standard consensus in the field" -- no, there doesn't. You repeatedly show a fundamental misunderstanding of what science is. Science is not authority. Science is evidence. Please read scientific method so you won't continue to waste our time.

And there's no SYNTH involved. I'm asking you to remove a claim that is contradicted by RS's. The claim itself is trivia that has no scientific value, so removing it detracts nothing from the article even assuming it's true. — kwami (talk) 09:55, 16 September 2021 (UTC)

Don't tell me I don't know how science works. Science works by peer review and collective understanding. Aristarchus was right that the Earth moved around the Sun, so were Galileo, Kepler and Copernicus. But the scientific community didn't accept it until Newton and Halley provided incontrovertable evidence. In this situation the evidence is still not incontovertable. We haven't imaged Orcus's disc; all evidence we have for its sphericity is indirect. There are reliable sources in this article that call Ceres the smallest dwarf planet. That said, I also know how Wikipedia works and know when I'm outnumbered. Serendi^podous 13:48, 16 September 2021 (UTC)

"Science works by peer review and collective understanding." Exactly. I wish you'd apply that standard to yourself.

You demand one standard for POV's you support, and another for ones you oppose. The evidence is not incontrovertible for either Orcus or Ceres. You're the one who wanted to abandon strict adherence to the evidence and follow usage in RS's. Now when RS's disagree with you, you object to that. Only the sources that agree with you should count. That's simply hypocrisy. — kwami (talk) 14:09, 16 September 2021 (UTC)

But you're doing the same thing! Serendi^podous 14:15, 16 September 2021 (UTC)

How am I doing the same thing? We have some sources that say A, and some that say not-A. You want to say A as if it were TRUTH and ignore the rest. I want to cover the different POVs per WEIGHT. I've shifted POV over the years as the sources have, and am willing to shift again if someone provides actual evidence. You have always rigidly adhered to what you think of as authority, regardless of RS's or evidence. You said it above: "there must be an authority!", which has been your mantra for a decade. It's a completely unscientific attitude. — kwami (talk) 14:24, 16 September 2021 (UTC)

The way I see it: it doesn't matter that Orcus is not universally accepted as a DP. What matters is that a lot of significant astronomers who are RS's accept it as one, and that a lot of those significant astronomers saying so are subject-matter experts: they are actually working on those TNO DP candidates. Because to them, the statement "Ceres is the smallest DP" would be wrong. They have a significant view making up a significant percentage of RS's. I don't think they should be completely ignored.

Which objects the IAU has actually accepted does not especially interest me. They might have set themselves up in a gatekeeping role in the planet-definition resolution, saying An IAU process will be established to assign borderline objects to the dwarf planet or to another category. But has this process ever been established? Since then, the IAU has outright said that there might be more DPs than the five they accepted. Which is exactly what you would expect if their definition was primary rather than their list of what they'd actually accepted. If it was their list that was primary, then they would be saying there that there were five DPs and that any more would be dependent on IAU processes. Evidently they've changed their tune since the resolution. Perhaps they decided that they did not really want to be in the business of gatekeeping the DPs at all. That would explain why, even though Tancredi gave his presentation at an IAU symposium back in 2009, and advised the IAU to at least officially accept Sedna, Orcus, and Quaoar, they've done nothing for over a decade.

At least saying that it's the smallest IAU-acknowledged DP and that many scientists think there could be smaller ones would be a true statement. A statement of doubtful importance IMHO, because (1) as I've said, the IAU is not really in the business of accepting DPs, and (2) it was considering even smaller Hygiea as a possibility in its draft definition of a planet, showing that this particular size threshold wasn't particularly important for it. But at least it would be a true and incontrovertible statement.

Incidentally, incontrovertible evidence was not exactly the standard most scientists used when it came to heliocentrism, surely? Newton gave a theory that heliocentrism naturally came out of. That is not the same as incontrovertible evidence for heliocentrism. Wasn't it only in 1728 that stellar aberration was found by James Bradley and proved that the Earth moved? But surely heliocentrism was already the standard view among astronomers by that date. Double sharp (talk) 14:32, 16 September 2021 (UTC)

For the record, that's why I said Newton and Halley, since it was the return of Halley's comet that confirmed Newtonian mechanics. Serendi^podous 15:05, 16 September 2021 (UTC)

Halley predicted in 1705 that the comet would return in 1758, which it did (although he would not live to see it). By which time Bradley had already found stellar aberration. I presume heliocentrism can only have been more standard among astronomers in 1758 than it was in 1728. :) Double sharp (talk) 15:16, 16 September 2021 (UTC)

Well, after I typed all that up, it turns out that the statement claiming Ceres as the smallest DP was removed anyway. I guess that probably resolves the issue. Double sharp (talk) 15:00, 16 September 2021 (UTC)

Comments by Nrco0e

Hi @Serendipodous, just checking in here. I'll be reviewing the older sources and adding some comments here from time to time. Nrco0e (talk · contribs) 08:09, 6 September 2021 (UTC)

• Transits of planets from Ceres

This section seems pretty shoddy, if not trivial to the article IMO. There's only one source used for this, and both archived and original links are dead. I've checked this link to "Solex" in Wayback Machine and it turns out to be some freeware program by a chemistry professor. It's almost a decade old now according to the date of last update, so the ephemerides are likely outdated or inaccurate. Unless there is another reliable source to back the dates given in this section, it's all WP:OR.

Couldn't find an alternative source, so removed. Serendi^podous 12:25, 6 September 2021 (UTC)

• "Additional imaging sessions, at increasingly better resolution took place on 25 January 4, 12, 19 and 25 February 1 March, and 10 and 15 April."

This is a bit difficult to read. Are there supposed to be commas separating the days of January/February/March from each other?

revised. Serendi^podous 23:04, 6 September 2021 (UTC)

• Hi User:Nrco0e and thanks for the comments. You happy how? Gog the Mild (talk) 19:35, 18 September 2021 (UTC)

Comments Oppose from TRM

Lead

• "minor-planet designation" our own article doesn't hyphenate this.

(Comment -- it should, per the MOS and use in e.g. International Comet Quarterly. The MPC doesn't use the phrase much, and then it's capitalized. — kwami (talk))

Well if it was being used adjectively then perhaps but here it's just saying that it has a "minor planet designation". Or is our own article in the wrong place? The Rambling Man (Keep wearing the mask...) 22:08, 16 September 2021 (UTC)

I would say it is. I moved it a decade ago, but it was moved back. Per our hyphen guidelines at the MOS, "minor planet designation" would be a minor designation of planets, "minor-planet designation" a designation of minor planets. People often don't bother to hyphenate, of course, especially when capitalizing. Here (discussing guidelines for naming comets) and here (on Pluto) they have "minor-planet designation", "minor-planet number", "permanent-number designation". But sometimes they omit the hyphen (once 'minor planet number' on the Pluto article; occasionally inconsistent with hyphens in other phrases); that just needs a bit of copy-editing. I've tried checking at the MPC, but AFAICT they don't seem to use the phrase much (in context, they just refer to "temporary/permanent designations"). Here's one from the IAU/MPC naming guidelines, where they need to disambiguate minor-planet designation from comet designation:

4.4 If the minor-planet designation was published before the realization is made that the object is a comet, the comet will retain the minor-planet designation. Otherwise, a new comet designation will be assigned.

4.5 If the object receives a permanent minor-planet number prior to its recognition as a comet, it shall be accorded "dual status". As such, it both retains the permanent minor-planet number and receives a new periodic-comet number.

Also here. — kwami (talk)

• "The first asteroid discovered, Ceres was first" first first... repetitive.
• "at Palermo Astronomical Observatory." the Palermo... and say where that is.
• Do you link asteroid in the opening sentences of the lead?
• "be rounded by its own gravity" this needs explanation.
• "peaking at opposition" again, jargon and indecipherable to most readers who aren't astrophyicists.
• "Despite this, Ceres's small size means that any internal ocean of liquid water it may have possessed has likely frozen by now, though brines still flow through the outer mantle and reach the surface, allowing cryovolcanoes such as Ahuna Mons to form at the rate of about one every 50 million years" 52-word sentence. Break it up.
• "tenuous, transient atmosphere" link atmosphere.

The Rambling Man (Keep wearing the mask...) 20:55, 16 September 2021 (UTC)

I should have said, there's a long way to go here for me. I'll do it in bite-sized chunks because I have a lot of other things ongoing. Feel free to ping me if I'm taking too long to get back to the review. The Rambling Man (Keep wearing the mask...) 22:09, 16 September 2021 (UTC)

@The Rambling Man: All issues addressed. Serendi^podous 09:52, 17 September 2021 (UTC)

History

• "For a time" not particularly encyclopedic. fixed
• "Mars and Jupiter" I normally expect to see items linked in the lead also linked on their first appearance in the main body.fixed
• "and mystic" what does that mean in this sense? Our "featured article" calls him a "German mathematician, astronomer, astrologer, and natural philosopher". The word "mystic" doesn't appear anywhere in his biography.
  • Well I have a citation that says he was. The guy believed that the ratios of planetary orbits needed to follow a preconceived pattern to agree with God's design. You OK with leaving that unexplained? Serendi^podous 19:46, 20 September 2021 (UTC)
    • I think you've already said he thought it was part of God's design, you don't need to ascribe him with "mystic". I don't believe that people on Twitter who say that Covid is all part of God's design are mystics, I just think they're bonkers. Probably best to just stick with reality. The Rambling Man (Keep wearing the mask...) 19:55, 20 September 2021 (UTC)
      • Fair enough. Serendi^podous 20:07, 20 September 2021 (UTC)
• " forever?" [19]" no space before ref.fixed
• "near 2.8 astronomical units (AU) from the Sun" could we put that into real human terms on this occasion for context for non-astrophysics readers?fixed

(Comment: IMO, "real human terms" would be AUs, because km distances of this scale are beyond our comprehension. Though it could be explained a x-times the distance of the Earth from the Sun. If we do add km, though, they should be a conversion, because the TB Law is best explained in terms of AUs. — kwami (talk))

Sure, but the conversion to km happens later in the article which is a little bit odd for me. The Rambling Man (Keep wearing the mask...) 19:46, 20 September 2021 (UTC)

Ah, sorry. Missed that. — kwami (talk)

• "editor of the astronomical journal" was it a German astronomical journal?fixed
• " the asteroids" link.fixed

That's a SEAOFBLUE issue, so it's likely to be reverted some day. The Pallas etc. articles link to asteroid also. — kwami (talk)

• "was Giuseppe Piazzi" link.fixed
• "observed ... observations" repetitive in a single sentence.fixed
• "Titius-Bode" en-dash.fixed
• "At 2.8 AU from the..." sentences uses "law" three times...fixed
  • You reverted your last fix. "It" is ambiguous here. [fixed myself] — kwami (talk)
• "within 10% of its actual value".... of??
  • Um, yes that is generally the accepted preposition to use when employing percentages. Serendi^podous 19:46, 20 September 2021 (UTC)
    • The actual value I meant. What was the "actual value" that the "within 10%" was?? The Rambling Man (Keep wearing the mask...) 19:55, 20 September 2021 (UTC)
      • Good point. fixed.Serendi^podous 20:13, 20 September 2021 (UTC)
        • That wasn't a fix. It's within 10%, not within 90%. [fixed myself] — kwami (talk) 05:20, 21 September 2021 (UTC)
• "as Hera, though" why in italics?fixed
• "preferred Juno" ditto?fixed
• "It would be replaced" It was replaced.fixed
• "distance of 419 million km" do this conversion above, where I suggested.fixed
• "Ceres was assigned a planetary symbol" when? I'm only asking really because in the same para you go on to say "remain listed ... for half a century".

(Comment: I found refs of 2 ppl who suggested it in 1802. I'm not sure it was ever "assigned" in an official sense, just that this is AFAICT the only symbol that people other than the suggesters ever used. — kwami (talk))

The date the symbol was first suggested is given elsewhere. "half a century" is from discovery, not from getting the symbol. And I'm not sure we can say when between 1852 and 1867 it stopped being considered a planet. (Indeed it was called a planet into the 20th century, as were other asteroids.) I changed to "for over half a century", but I don't see anything that needs to be fixed here. — kwami (talk)

• "Then, in 2006" is "Then," adding anything here?fixed
• "have "cleared the neighborhood around its orbit" this is linked here, but is this the same thing as "whether the gap had been cleared by the gravity of Jupiter" above?
  • No. Jupiter has cleared its own neighborhood, not any other planets'. Serendi^podous 19:46, 20 September 2021 (UTC)
    • I mean does "cleared" mean the same thing each time here? If so, why wouldn't we link "cleared" the first time? If not, it's confusing because it appears to be using the same terminology for different things. The Rambling Man (Keep wearing the mask...) 19:56, 20 September 2021 (UTC) fixed

That's the next section done. Just out of interest, I see in the infobox the use of "curly" punctuation, "0.854″ to 0.339″" is this MOS compliant? Also in the infobox I see "A899 OF1943 XB" as alternative designations but they're not mentioned in the article and thus not seemingly referenced anywhere? The Rambling Man (Keep wearing the mask...) 19:06, 20 September 2021 (UTC)

(A899 is a retroactive MP number, found at JPL but not at the MPC [or maybe the reverse, I forget]. There's another number or two that were assigned to an object that was later found to be an error for Ceres. I don't know how notable either of them is. — kwami (talk))

Sure, where are they mentioned/referenced in the main part of the article? Or are we not referencing such things? The Rambling Man (Keep wearing the mask...) 19:57, 20 September 2021 (UTC)

We usually don't bother, but this is a FA. So yeah, best to either ref (and maybe explain in the text) or delete. — kwami (talk) 03:28, 21 September 2021 (UTC)

I did find an article explaining A899 OF, but can't access it. Maybe someone else can. Also, it is in German.

Based on the way these designations work, this and 1943 XB must be claimed asteroid discoveries that later turned out to be just Ceres.

″ in the infobox is not curly punctuation, it's a double prime meaning arcseconds. Double sharp (talk) 04:47, 23 September 2021 (UTC)

IMO the two MP numbers for misidentified objects are trivia. There are more important things we don't bother with, so I don't know why we'd include those when they're not even important enough for a RD. The retroactive number is more reasonable, IMO, but the fact that the MPC itself doesn't use it make me doubt its value. — kwami (talk) 08:58, 23 September 2021 (UTC)

I agree that they are trivia, but they do seem to be often included. For an example with lots of them, see 333 Badenia, with no fewer than nine provisional designations included. So if we decide that they are not valuable inclusions, then presumably we should remove them from a lot more asteroid articles. Double sharp (talk) 09:36, 23 September 2021 (UTC)

OK I take it back. 120 Lachesis also has some extra provisional designations, but they're not at its article. So I now think it's fine to remove the trivia of A899 OF and 1943 XB from the Ceres infobox. I've just hidden them. Double sharp (talk) 02:38, 24 September 2021 (UTC)

Even though the orbital ref is JPL from just two years ago, the numbers have changed. E.g. e from 0.0760 to 0.0783. — kwami (talk) 05:16, 23 September 2021 (UTC)

Orbit

• "Ceres follows an orbit.." sentence has "orbit" three times, repetitive reading.fixed
• Next sentence has "orbit" four times...fixed
• "the Gefion asteroid family.[47] The asteroids of this family" merge these, "the Gefion asteroid family, members of which..."fixed
• "have spectral properties" in what sense?fixed
• "makeup" isn't "composition" a better word here?fixed
• "over the age of the Solar System" could link this.fixed
• "temporary 1:1 resonant orbital relationships" what does this mean?fixed
• "up to 2 million" two.fixed
• "with Pallas (their" overlinked.fixed

Rotation and axial tilt

• "hopping an average of 3 times" hopping? and 3->three.
  • That's the word used in the source. Serendi^podous 12:45, 23 September 2021 (UTC)

• "Dawn, the first spacecraft.." link again here.fixed
• " of 3 million" threefixed

Issues addressed. Serendi^podous 12:45, 23 September 2021 (UTC)

Takes me to "Geology". The Rambling Man (Keep wearing the mask...) 11:45, 23 September 2021 (UTC)

Geology

• You link "Moon" twice and it's just struck me that the first one is an easter egg, i.e. "similar to the situation on the Moon and Mercury" should probably have "situation on the" included in the pipe. fixed
• "partial differentiation of its rocky fraction" what does that mean?fixed
• "the Hubble Space Telescope reveal" link.fixed
• "in Ernutet crater" are any other craters on Ceres named? Shouldn't this article cover the major geographical features by name?
  • There are 151 named features on Ceres. You want me to cover all of them? Serendi^podous 20:17, 23 September 2021 (UTC)
    • Well this is FA. I imagine that if they're not covered here, they ought to be covered in a Features of Ceres or similar article, right? The Rambling Man (Keep wearing the mask...) 20:52, 23 September 2021 (UTC)
      • Well that's what Geology of Ceres and List of geological features on Ceres are for. Serendi^podous 21:13, 23 September 2021 (UTC)
      • I apologise that I may have missed the clear links to those articles at this point. The Rambling Man (Keep wearing the mask...) 21:15, 23 September 2021 (UTC)
• "Dawn revealed that" Dawn is overlinked here. fixed
• "is just 284 km" but the entire diameter of Ceres is 939.4 km, so why "just"? That's almost a third of the diameter of the asteroid.
  • Yes but models had suggested it should have 10-15 craters 400 km in diameter. Serendi^podous 20:17, 23 September 2021 (UTC)
    • I would drop the "just". It feels like there's too much implied by it, especially as a non-expert who finds it hard to conceive that a crater could occupy 1/3 of an oblate spheroid's diameter... The Rambling Man (Keep wearing the mask...) 20:52, 23 September 2021 (UTC) OK
      • Well, Mercury, the Moon, and Mars all have craters proportionately that big. :) The South Pole–Aitken basin on our moon has 70% of the diameter of the moon itself. Rheasilvia on Vesta has 90%. So such huge craters are not unknown in the solar system, though I agree that it's surprising for those not in the know. But I guess the sentences are still clearly connected. Double sharp (talk) 02:44, 24 September 2021 (UTC)
• "early cryovolcanism.[69] Three" link. fixed
• "15 km (10 mi) of elevation" avoid starting sentences with numerals. fixed
• "to be a cryovolcano and" link that first time. fixed
• "the largest confirmed impact basin on Ceres" you already said just that, the section above. fixed
• "named Cerealia Facula" why in italics? Why two words? Why is facula linked in the first use?
  • I thought you wanted first uses to be linked. Serendi^podous 20:17, 23 September 2021 (UTC)
    • I meant why isn't it linked first time?? The Rambling Man (Keep wearing the mask...) 21:15, 23 September 2021 (UTC) fixed
• "east, Vinalia Faculae" similar, why italics? fixed
• "Near-infrared" could link. fixed
• You link "sodium carbonate" but not, for instance, "ammonium chloride"? fixed I think
• "Cerealia dome"? that was a facula last time?
  • different thing. Serendi^podous 20:17, 23 September 2021 (UTC)
    • what is this then? The Rambling Man (Keep wearing the mask...) 21:15, 23 September 2021 (UTC)
      • added. Serendi^podous 21:34, 23 September 2021 (UTC)

That takes me to "Tectonic features". The Rambling Man (Keep wearing the mask...) 19:25, 23 September 2021 (UTC)

Tectonics et seq.

• "Although Ceres lacks plate tectonics,[74] with the vast majority of its surface features linked either to impacts or to cryovolcanic activity, several potentially tectonic features have been tentatively identified on Ceres, particularly in its eastern hemisphere." just basic grammar here. why repeat Ceres in this lengthy sentence?
• "than 105 m (344 ft) on " in diameter?
• "These boulders are". They were...
• "larger than 100 m (300 ft)." again, in diameter?
• "higher latitudes than at lower latitudes" repetitive prose.
• "possess salinity of " link.
• "40% or 50% " not 45? or 49? Come on, professional prose here.
• "is on the order of 1000" of the order, not "on" the order.

Honestly, I'm getting to the point where I think this needs booting back to some kind of peer review. I'm not really here to pick up basic English issues. I'm out for now. The Rambling Man (Keep wearing the mask...) 21:10, 24 September 2021 (UTC)

• • • I'm sorry but I launched a peer review before I took this to FAC, and you weren't there. No one seemed interested in peer reviewing it when the time would have been apropos. Serendi^podous 21:40, 24 September 2021 (UTC)
      • No need to apologise to me. I don't frequent PR, that's something that others use. I never use it, it's dead as far as I'm concerned, but the prose here needs a review. I can't keep doing it as part of FAC, sorry. The Rambling Man (Keep wearing the mask...) 21:43, 24 September 2021 (UTC)
  • The review is currently twice the length of the article. It's not what I'd expect at FAC. The Rambling Man (Keep wearing the mask...) 21:24, 24 September 2021 (UTC)

Source review

Taking a gander at the sourcing now. Some questions:

• What are the criteria for using and not using particular identifiers (such as arXiv)?
• Source #5 and #37 either do not explain who published and authored it, or only incompletely. fixed
• Regarding #6, I know that WP:CALC applies to FAC, but are we sure that we can calculate these values simply by using a formula? Planetary bodies are not simple spheres after all.
• Why is #12 formatted differently from other Icarus sources?
  • Is it? Serendi^podous 13:27, 23 September 2021 (UTC)
    • It is (the extra link). Jo-Jo Eumerus (talk) 18:55, 23 September 2021 (UTC)
      • It's because, unlike the other citations, it possesses a link to the full article, rather than merely an abstract. Serendi^podous 20:20, 23 September 2021 (UTC)
• #23 isn't there a better source for this astronomical community fact than The Guardian?
  • subbed with a book Serendi^podous 13:27, 23 September 2021 (UTC)
• I take that the pronunciation of "cererean" didn't change over the last 100 years.

I can't find it in any recent dict, but the pronunciation of those old sources is what we would expect in English from the Latin genitive singular Cereris. Pronunciations of Latin terms typically don't deviate from the expected one unless the word is common enough for an alt pronunciation to become established. E.g. 'Patroclus' has an irregular pronunciation (stress on the 'o') because Pope changed the stress placement to fit the meter of his translation of the Iliad, and it stuck because generations of students were raised on it. — kwami (talk) 21:19, 23 September 2021 (UTC)

Also Uranus, I guess. Double sharp (talk) 02:49, 24 September 2021 (UTC)

• #34 does not seem to be a good source for the claim that the sickle is the astronomical symbol. fixed
• #61 is not being used as a source, I think it would be better put as a footnote. fixed
• I note some slight inconsistencies in citation format; sometimes the title of the ref is first and sometimes the authors.
  • Some were due to incomplete citation, but most are just because some citations don't have listed authors. Serendi^podous 20:46, 23 September 2021 (UTC)
• #142 is also formatted differently from other sources. fixed

For what it's worth all the sources used seem FAC-suitable to me, but note that I didn't perform a spot-check. Jo-Jo Eumerus (talk) 09:38, 23 September 2021 (UTC)

Excellent catch about #6. Ceres is nearly an oblate spheroid, and the formulae given for that at Ellipsoid#Surface area gives a surface area of closer to 2.72 million km² than what we currently have (2.77). So it seems that Ceres is flattened enough to affect the answer up to 3 s.f. The volume is close enough, though. I guess the surface gravity also should be checked, especially because Ceres is not only flattened but also rotates quickly (these are related facts). Alas, per doi:10.1016/j.icarus.2018.11.023 this is quite complicated. Double sharp (talk) 09:53, 23 September 2021 (UTC)

User Kheider is someone we could expect to get it right. — kwami (talk) 23:39, 23 September 2021 (UTC)

Well, let's ping him then: @Kheider: Double sharp (talk) 02:49, 24 September 2021 (UTC)

Would https://solarsystem.nasa.gov/planets/dwarf-planets/ceres/by-the-numbers/ be good for avoiding WP:CALC? -- Kheider (talk) 15:21, 24 September 2021 (UTC)

Maybe [I am a little unsure how they got their data]. Jo-Jo Eumerus (talk) 18:15, 24 September 2021 (UTC)

It's a RS. Unless we notice that they got it wrong, it should be good enough. — kwami (talk) 22:28, 24 September 2021 (UTC)

The surface area they quote is incompatible with the dimensions we quote. (For Wolfram Alpha, you need to give the semi-axes.) Instead the surface area they quote is exactly what you would get if you took their equatorial radius, substituted it into $A=4\pi r^{2}$, and didn't know anything about significant figures. And in fact, because they take the equatorial radius rather than the mean radius (and because Ceres is oblate), they get a value that is actually further off than the one we currently have. So no, I'm not happy with this source. But all the conflicts do disappear if you cut off one significant figure from what we give, and I suppose that would also take care of the surface gravity issue. Double sharp (talk) 08:25, 25 September 2021 (UTC)

doi:10.1029/2020JE006640 gives Ceres surface gravity as 0.27 m·s⁻² (we have 0.28 m·s⁻² per formula). No source for how they got it, but agreement seems fair (close to theoretical value for a sphere; I can believe that oblateness affects it to this extent). For practical purposes, it's probably best thought of as 0.03g. Double sharp (talk) 08:33, 25 September 2021 (UTC)

*Sigh* I should know by now not to trust NASA/JPL websites, and shouldn't have called them RS. Your 2nd source, though, I should hope they got it right! They only give a single number, though. If the variation in surface g by location isn't significant, then we can ignore rotational effects. — kwami (talk) 11:14, 25 September 2021 (UTC)

I should hope so too, since their conclusion probably doesn't depend on that level of accuracy. After all, they compare Iapetus and Charon as having similar gravity to Ceres. But at least it is a referenced value. I should like to be able to calculate it to check, though. Double sharp (talk) 12:48, 25 September 2021 (UTC)

Coordinator comment

Having noted The Rambling Man's oppose I have read through some sections of this article myself. It is quite clear that despite the large amount of work by the nominator and numerous reviewers the article is not ready for FAC in terms of prose. I am therefore archiving it. I would suggest PR and/or GoCE and/or involving a collaborator with a sound grasp of the prose expectations at FAC. There is clearly a lot of work to do, so the usual two week hiatus will apply; although I would expect the work needed on this article to take longer than that. Gog the Mild (talk) 10:11, 1 October 2021 (UTC)

• Closing note: This candidate has been archived, but there may be a delay in bot processing of the close. Please see WP:FAC/ar, and leave the {{featured article candidates}} template in place on the talk page until the bot goes through.

The above discussion is preserved as an archive. Please do not modify it. No further edits should be made to this page.