Talk:List of Solar System objects by size

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Outer System asteroids larger than radius 50 km.

This is a good source (last updated Feb 23, 2021) of all outer solar system asteroids (Kuiper Belt and beyond) estimated to have diameters 101 km or larger: http://web.gps.caltech.edu/~mbrown/dps.html 2603:6010:9C07:AC00:107:CB1F:13B1:8666 (talk) 22:38, 16 August 2022 (UTC)

Still hasn't updated w Gonggong's name! I bet "updated daily" hasn't been true for a decade. — kwami (talk) 11:28, 17 August 2022 (UTC)

Now listed as having been updated 5 May 2023. And yet Gonggong's name is still not there. Double sharp (talk) 08:10, 4 February 2024 (UTC)

What happened?

Why is the first section of this list now sorted by mass rather than size? If the reader wants to sort the table by mass, they can easily do so, but the default sorting should be by size, as stated in the article title. SevenSpheresCelestia (talk) 23:55, 28 August 2022 (UTC)

Restored, though I seem to have glitched Mercury's colour. Can't figure out how to change it. Serendi^podous 10:06, 29 August 2022 (UTC)

I don't see anything off. — kwami (talk) 07:19, 1 September 2022 (UTC)

Given that QB1 has a name

Isn't the term "cubewano" obsolete? Serendi^podous 22:56, 31 August 2022 (UTC)

I don't see why it should be. "Shrive" is obsolete, but "short shrift" lives on. If we find RS's are abandoning the term, we can of course follow. — kwami (talk) 07:16, 1 September 2022 (UTC)

Here's a 2021 article referring to both "Albion" and "cubewano". Google Scholar doesn't list many recent articles giving "cubewano", so maybe it is getting abandoned. Double sharp (talk) 08:10, 1 September 2022 (UTC)

A quick method of calculating Surface Gravity using the Radius ( km ), and Density ( g/cm^3) or ( kg/m^3)

If you want to make a quick check of the surface gravity values listed in the article, You can Multiply the Radius times the Density, and divide by 3582.0 to get a very close estimate of the surface gravity in meters per second squared. The 3582 is rounded up from a calculated value of 3581.980 743. (calculated from Earth using RX Den / 9.80665 = ). The Wikipedia Values for the four gas giants are lower than the ( Radius X Density )/ 3582, but nearly all of the rest of the numbers will have the Wikipedia Values being slightly higher, but usually still close. The Numbers are close down to Iapetus, but the Wikipedia Values are sometimes way off, and sometimes very close to the bottom of the orbs that still list surface gravity. A Radius X Density = 3582 is almost exactly 1.0 meters per second squared. This will allow you to Create a graph with Radius on one axis, and density on the other axis, and a straight line. Some planets will plot above the line (greater radius with lower density), and some will plot below the line with (lesser radius, and higher density). Remember that density is related to both composition of the materials collected by the orb, and the internal temperature of the orb, and the stratification of the materials inside the orb. Have Fun. Michael W. Clark, Golden Colorado 98.245.216.62 (talk) 02:20, 4 September 2022 (UTC)

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A way to quickly estimate the Surface gravity of an Object as compared to the Earth

A quick way to estimate the surface gravity of any object in the Solar System is to make a ratio of the Radius X Density of the object of interest divided by the Radius X Density of the Earth. The Earth Radius X Density is 6371.0084 X 5.5136 = 35,127.19191 (km)x(kg.m^3), this becomes the denominator. For example: Using the Sun Radius X Density = 695,508 X 1.409 = 979,970.772. The Ratio is thus 979,970.772 / 35,127.19191 = 27.897 782 85 X that of the Surface gravity of the Earth. So 27.897 782 85 X 9.80665 = 273.583 7922 meters per second squared. You can round as desired, and compare this value to other published values. This could also be a quick way to see if either a Radius, or a Density is close enough to not need changing since satellite trajectories can be used to calculate the actual total mass of an object, and thus the actual surface gravity. An important concept here is that radius, and density are interlinked. If a radius for an object with a known mass increases, then its density decreases. Radius, and Density will plot on Hyperbolic lines where the area under the curve gives the Radius X Density, and thus it will give the surface gravity as well. Michael W. Clark, Golden Colorado 98.245.216.62 (talk) 18:39, 30 October 2022 (UTC)

Coincidence or not?

Earth is the fifth largest planet in our solar system, and Earth's Moon is the fifth largest moon in our solar system. Should this be regarded as a coincidence? Ar Colorado (talk) 19:00, 5 January 2023 (UTC)

Yes. — kwami (talk) 08:58, 6 January 2023 (UTC)

Add Hesperia (69)

please do as it is one of the first 100 minor planets. 138 km or 110 ± 15 km ZokiZokias (talk) 22:26, 27 February 2023 (UTC)

Done. P Aculeius (talk) 23:12, 27 February 2023 (UTC)

Are we ever going to feature this list?

There was a time, aeons ago, when the plan was to get this list featured and then to transform List of Solar System objects by orbit into a similar-style list but with orbital elements. Is this list featurable or is it just too vast to be cleaned? Serendi^podous 21:46, 29 July 2023 (UTC)

Can someone please add this new pie chart image into the article?

The piechart for the relative masses of the rounded moons is a complete mess. The moons aren't in the order listed, and the smaller ones can't be seen at all.

I made a pie chart, well 2 of them but they're in the same image, which I believe shows the relative mass of the moons much better.

I'd love to upload it but i don't know how. I uploaded it at https://ibb.co/54K0G8D. If someone could upload it on my behalf I'd appreciate it :)

And also just in case of legal jargon, yes i consent and there's no copyright etc IAPETUSOUTSOLD (talk) 06:27, 11 November 2023 (UTC)

radius for 2002 MS4 307261 ?

This paper: https://orbi.uliege.be/bitstream/2268/253802/1/EPSC2020-866-print.pdf gives a radius of 385 +/- 1km. Is that a better, or obsolete, estimate or measurement compared to the one currently in the table? If more correct, we may need to move that object down to the next table. Dhrm77 (talk) 19:54, 20 November 2023 (UTC)

Low importance

Why the list is at "low importance" at WikiProject Astronomy? I think that is should be of mid or high importance. InTheAstronomy32 (talk) 11:01, 14 February 2024 (UTC)

It's a list, and relatively obscure. I do agree that it should be cleaned up and given more attention, but this is significantly lower priority than, say, articles covering basic topics and objects in astronomy. ArkHyena (talk) 05:08, 22 March 2024 (UTC)

Table row background coloring

I brought back table row background coloring after it got purged a number of years ago. I'm open to suggestions on how to improve it before I go on to apply it to all the other tables (currently only applied to the largest objects). I feel it greatly improves casual readability to be able to see the classification of objects at a glance. Something that was somewhat better back in earlier versions of this page from 2019 or so. For example: https://en.wikipedia.org/w/index.php?title=List_of_Solar_System_objects_by_size&oldid=917747673 Anyway, if anyone has suggestions please mention them. Ergzay (talk) 02:32, 16 March 2024 (UTC)

guys can I pretty please color everything (like the >400 km radius section)

pretty please :) 2603:8001:C401:3D45:75B2:D3E0:1EAB:64DE (talk) 02:06, 22 March 2024 (UTC)

We CANNOT measure the mass of any of these objects

Since we cannot put any of these objects on a scale in a known acceleration we CANNOT know the mass of any of them. All we can know is the acceleration which they impart to other objects in the Solar System, But the acceleration is as we all learned in high school determined by the product of the Gravitational Constant and their mass. However the value of the Gravitational Constant has only been measured to four decimals, whereas because of three thousand years of astronomical observations combined with tracking of space probes we know the value of GM for most of these objects to at least eight decimals.

For example the value of GM for the Earth is 3.986 004 42 x 10^14 m^3/s^2, nine digits. To make the "mass" of a solar system body meaningful to non-scientists it can be convenient to divide the value of GM for the body by the value of GM for the Earth, and you end up with a meaningful and useful value accurate to at least 8 digits. But the moment that you ask for a value in pounds or kilograms you get a completely useless number which is only accurate to 4 digits. In particular if some amateur decides to create a personal numerical simulation of the motion of Solar System bodies by directly applying Newton's Law F=GM1M1/r^2, the result will be inaccurate because of the use of the inaccurate value of G.

The column for "Mass" in all similar tables throughout Wikipedia should therefore be replaced by a column containing the product GM. Jamescobban (talk) 23:04, 19 April 2024 (UTC)

No, it shouldn't. That won't mean anything to most people.

We can just give the mass to 4 digits, if known that precisely, or to 5 digits with its uncertainty. Since after all we give G to 5 or 6 digits with the uncertainty in the last digit or two.

Also, please don't spam a bunch of articles with this. I think 4 is enough. — kwami (talk) 00:58, 20 April 2024 (UTC)

(In general, with a few exceptions where the extra precision is meaningful, we probably shouldn't give any figures to more than 3 or 4 digits. — kwami (talk) 01:05, 20 April 2024 (UTC))

Convince the astronomy and physics communities that mass estimates are meaningless, get this published on reputable scientific journals, and come back. So far, your suggestion would violate WP:FRINGE. cyclopia^speak! 10:30, 18 May 2024 (UTC)

We never define "mean radius"

What exactly do we mean when we say "mean radius", and more importantly, where do we say so? There is no wiki-link, and there is no article mean radius (or mean diameter, for that matter) to link to. Simply pointing to radius doesn't do the trick, since there is nothing in that article to explain what's "mean" about it. Linking mean and radius separately would work, if there was a section in either article to explain what kind of mean this is. I would have liked to point to the definition in User talk:FriarTuck1981#"Mean anomaly" vs. "mean diameter", but couldn't. Both mean radius and mean diameter are used all over astronomy articles on Wikipedia (including template:Infobox planet and template:Infobox comet), but their meaning is never actually clarified. Renerpho (talk) 10:03, 17 June 2024 (UTC)

My thought would be to start with the definition for the Earth, and extend it to other bodies. There are some papers on that topic, although access is an issue. Praemonitus (talk) 13:51, 17 June 2024 (UTC)

@Praemonitus: It is quite amusing that nobody bothers to define it, because everybody thinks it's obvious! It's the geometric mean, meant to be volume-mean radius (the radius of a sphere with the same volume as the object, or as the best-fit ellipsoid) unless stated otherwise, but it's hard to find a source that just plainly says so. For example, the Oxford Dictionary of Astronomy uses the term frequently,[1] but does not bother to give a definition. Their numbers (as in the examples Ceres, p.80; and Davida, p.115) demonstrate that they refer to volume-mean diameters: For Ceres, an oblate spheroid 975 x 909 km, mean diameter 952 km (assumed shape $a\cdot a\cdot c$, mean diameter ${\sqrt[{3}]{975\cdot 975\cdot 909}}=952$); for Davida, dimensions 360 x 294 x 254 km, mean diameter 300 km (assumed shape $a\cdot b\cdot c$, mean diameter ${\sqrt[{3}]{360\cdot 294\cdot 254}}=300$). The conventions involved are by no means obvious to the casual reader.

Leconte, 2011 defines it on p.9, §5.2, and Chambat, 2001 demonstrates the case of an equatorial and a polar axis (like for the Ceres example) on p.4, formula 29. I think we can use those. The former of those nicely states: Before going further, it is important to summarize the differences between the various radii that we have defined above. In the literature, the term “radius” is used loosely, even for nonspherical objects. [...] For any distorted object, we can define the mean radius (R) as the radius of the sphere that would enclose the same volume as the described surface. Renerpho (talk) 15:18, 17 June 2024 (UTC)

I went ahead and created mean radius, with mean diameter as a redirect. Renerpho (talk) 23:33, 17 June 2024 (UTC)

Gave it a bit of a spit shine and some more conceptual explanations Headbomb {t · c · p · b} 23:20, 3 July 2024 (UTC)

What is the "all else" in the solar system parts per million image?

In the first picture of this article which displays the mass of the solar system in parts per million it has "all else" listed in green at 150 ppm? That seems kind of high to me, no? All the planets are already displayed which means that the dwarf planets, moons, and asteroids, would account for 3 times the mass of Neptune. Is that number incorrect or is there something I’m not seeing here? 69.162.253.57 (talk) 01:00, 3 July 2024 (UTC)

Alright, so I did some cursory addition for the most massive moons in the Solar System, and I was only able to get a value on the ballpark of ~0.1 Earth masses. I doubt adding all moons smaller than Triton will be capable of bringing this up to 0.2. The mass of the Kuiper belt is estimated to be around 0.01 Earth masses, with the main belt an order of magnitude lower than that. The scattered disc and Oort cloud may represent massive reservoirs of undiscovered material, but even including the hypothetical Planet 9 I doubt they would cumulatively surpass 10–20 Earth masses. @Cmglee:, if possible could you clarify why "all else" appears to be significantly overrepresented here? ArkHyena (talk) 02:39, 3 July 2024 (UTC)

Mass Distribution Within the Solar System

99.85 percent	Sun
0.135 percent	The Eight Classical Planets
0.015 percent	Comets Kuiper belt objects Satellites of the planets Dwarf Planets Asteroids Meteoroids Interplanetary Medium

@ArkHyena: This value comes from http://solarsystem.nasa.gov/basics/chapter1-1/metrics/aggregate/page_action/aggregate#Sun as on the right. Cheers, cmɢʟee⎆τaʟκ 07:31, 3 July 2024 (UTC)

it might be a rounding error? .0150 ppm instead of 150 ppm Phaserblast (talk) 21:40, 3 September 2024 (UTC)

Reposting: Are we ever going to feature this list?

There was a time, aeons ago, when the plan was to get this list featured and then to transform List of Solar System objects by orbit into a similar-style list but with orbital elements. Is this list featurable or is it just too vast to be cleaned? Serendi^podous 00:52, 15 September 2024 (UTC)

The PERFECT chart of Solar System Objects by size

This is the perfect chart of what you are looking for. Largest Sun Jupiter Saturn Uranus Neptune Earth Venus Mars Ganymede Titan Mercury Moon Pluto Everthing Else 103.50.81.150 (talk) 10:52, 13 October 2024 (UTC)