The Parker Solar Probe (PSP; previously Solar Probe, Solar Probe Plus or Solar Probe+)[6] is a NASA space probe launched in 2018 with the mission of making observations of the outer corona of the Sun. It will approach to within 9.86 solar radii (6.9 million km or 4.3 million miles)[7][8] from the center of the Sun, and by 2025 will travel, at closest approach, as fast as 690,000 km/h (430,000 mph) or 191 km/s, which is 0.064% the speed of light.[7][9] It is the fastest object ever built.[10]

Parker Solar Probe
Digital model of a spacecraft with a bus attached to a larger sun-shield. Two small solar panels are attached to the side of the bus, along with four rear-facing antennas.
Model of the Parker Solar Probe
NamesSolar Probe (before 2002)
Solar Probe Plus (2010–2017)
Parker Solar Probe (since 2017)
Mission typeHeliophysics
OperatorNASA / Applied Physics Laboratory
COSPAR ID2018-065A Edit this at Wikidata
SATCAT no.43592
Websiteparkersolarprobe.jhuapl.edu
Mission duration7 years (planned)
Elapsed: 6 years, 3 months and 8 days
Spacecraft properties
ManufacturerApplied Physics Laboratory
Launch mass685 kg (1,510 lb)[1]
Dry mass555 kg (1,224 lb)
Payload mass50 kg (110 lb)
Dimensions1.0 m × 3.0 m × 2.3 m (3.3 ft × 9.8 ft × 7.5 ft)
Power343 W (at closest approach)
Start of mission
Launch date12 August 2018, 07:31 UTC [2][3]
RocketDelta IV Heavy / Star-48BV[4]
Launch siteCape Canaveral, SLC-37
ContractorUnited Launch Alliance
Orbital parameters
Reference systemHeliocentric orbit
Semi-major axis0.388 AU (58.0 million km; 36.1 million mi)
Perihelion altitude0.046 AU (6.9 million km; 4.3 million mi; 9.86 R)[note 1]
Aphelion altitude0.73 AU (109 million km; 68 million mi)[5]
Inclination3.4°
Period88 days
Sun
Transponders
BandKa-band
X-band
Artwork of the spacecraft next to the Sun, enclosed in a circle with a yellow border. The words "Parker Solar Probe" are placed around the interior of the border, while the words "a mission to touch the Sun" are written inline in a smaller font in the bottom right of the image.
The official insignia for the mission.

The project was announced in the fiscal 2009 budget year. Johns Hopkins University Applied Physics Laboratory designed and built the spacecraft,[11] which was launched on 12 August 2018.[2] It became the first NASA spacecraft named after a living person, honoring physicist Eugene Newman Parker, professor emeritus at the University of Chicago.[12]

A memory card containing names submitted by over 1.1 million people was mounted on a plaque and installed below the spacecraft's high-gain antenna.[13] The card also contains photos of Parker and a copy of his 1958 scientific paper predicting important aspects of solar physics.[14]

On 29 October 2018, at about 18:04 UTC, the spacecraft became the closest ever artificial object to the Sun. The previous record, 42.73 million kilometres (26.55 million miles) from the Sun's surface, was set by the Helios 2 spacecraft in April 1976.[15] At its perihelion on 27 September 2023, the PSP's closest approach was 7.26 million kilometres (4.51 million miles),[16] reaching this distance again on 29 March 2024.[17] This will be surpassed after the remaining flyby of Venus.

History

edit

The Parker Solar Probe concept originates in the 1958 report by the Fields and Particles Group, Committee 8 of the National Academy of Sciences' Space Science Board,[18][19][20] which proposed several space missions including "a solar probe to pass inside the orbit of Mercury to study the particles and fields in the vicinity of the Sun".[21][22]

Studies in the 1970s and 1980s reaffirmed its importance,[21] but it was always postponed due to cost. A cost-reduced Solar Orbiter mission was studied in the 1990s, and a more capable Solar Probe mission served as one of the centerpieces of the Outer Planet/Solar Probe (OPSP) program formulated by NASA in the late 1990s. The first three missions of the program were planned to be: the Solar Orbiter, the Pluto and Kuiper belt reconnaissance Pluto Kuiper Express mission, and the Europa Orbiter astrobiology mission focused on Europa.[23][24]

 
Evolution of PSP design

The original Solar Probe design used a gravity assist from Jupiter to enter a polar orbit which dropped almost directly toward the Sun. While this explored the important solar poles and came even closer to the surface (3 R, a perihelion of 4 R),[24] the extreme variation in solar irradiance made for an expensive mission and required a radioisotope thermal generator for power. The trip to Jupiter also made for a long mission, 3+12 years to first solar perihelion, 8 years to second.

Following the appointment of Sean O'Keefe as Administrator of NASA, the entirety of the OPSP program was canceled as part of President George W. Bush's request for the 2003 United States federal budget.[25] Administrator O'Keefe cited a need for a restructuring of NASA and its projects, falling in line with the Bush Administration's wish for NASA to refocus on "research and development, and addressing management shortcomings".[25]

In the early 2010s, plans for the Solar Probe mission were incorporated into a lower-cost Solar Probe Plus.[26] The redesigned mission uses multiple Venus gravity assists for a more direct flight path, which can be powered by solar panels. It has a higher perihelion, reducing the demands on the thermal protection system.

In May 2017, the spacecraft was renamed the Parker Solar Probe in honor of astrophysicist Eugene Newman Parker,[27][28] who had proposed the existence of nanoflares as an explanation of coronal heating[29] as well as having developed a mathematical theory that predicted the existence of solar wind.[30] The solar probe cost NASA US$1.5 billion.[31][32] The launch rocket bore a dedication in memory of APL engineer Andrew A. Dantzler who had worked on the project.[33]

Spacecraft

edit

The Parker Solar Probe is the first spacecraft to fly into the low solar corona. It will assess the structure and dynamics of the Sun's coronal plasma and magnetic field, the energy flow that heats the solar corona and impels the solar wind, and the mechanisms that accelerate energetic particles.

The spacecraft's systems are protected from the extreme heat and radiation near the Sun by a solar shield. Incident solar radiation at perihelion is approximately 650 kW/m2, or 475 times the intensity at Earth orbit.[1][34]: 31  The solar shield is hexagonal, mounted on the Sun-facing side of the spacecraft, 2.3 m (7 ft 7 in) in diameter,[35] 11.4 cm (4.5 in) thick, and is made of two panels of reinforced carbon–carbon composite with a lightweight 11-centimeter-thick (4.5 in) carbon foam core,[36] which is designed to withstand temperatures outside the spacecraft of about 1,370 °C (2,500 °F).[1] The shield weighs only 73 kilograms (160 lb) and keeps the spacecraft's instruments at 29 °C (85 °F).[36]

A white reflective alumina surface layer minimizes absorption. The spacecraft systems and scientific instruments are located in the central portion of the shield's shadow, where direct radiation from the Sun is fully blocked. If the shield were not between the spacecraft and the Sun, the probe would be damaged and become inoperative within tens of seconds. As radio communication with Earth will take about eight minutes in each direction, the Parker Solar Probe has to act autonomously and rapidly to protect itself. This will be done using four light sensors to detect the first traces of direct sunlight coming from the shield limits and engaging movements from reaction wheels to reposition the spacecraft within the shadow again. According to project scientist Nicky Fox, the team describe it as "the most autonomous spacecraft that has ever flown".[6]

The primary power for the mission is a dual system of solar panels (photovoltaic arrays). A primary photovoltaic array, used for the portion of the mission outside 0.25 au, is retracted behind the shadow shield during the close approach to the Sun, and a much smaller secondary array powers the spacecraft through closest approach. This secondary array uses pumped-fluid cooling to maintain operating temperature of the solar panels and instrumentation.[37][38]

Trajectory

edit
 
An animation of the Parker Solar Probe's trajectory from August 7, 2018, to August 29, 2025:
  Parker Solar Probe ·   Sun ·   Mercury ·   Venus ·   Earth
For more detailed animation, see this video.

The Parker Solar Probe mission design uses repeated gravity assists at Venus to incrementally decrease its orbital perihelion to achieve a final altitude (above the surface) of approximately 8.5 solar radii, or about 6×10^6 km (3.7×10^6 mi; 0.040 au).[35] The spacecraft trajectory will include seven Venus flybys over nearly seven years to gradually shrink its elliptical orbit around the Sun, for a total of 24 orbits.[1] The near Sun radiation environment is predicted to cause spacecraft charging effects, radiation damage in materials and electronics, and communication interruptions, so the orbit will be highly elliptical with short times spent near the Sun.[34]

The trajectory requires high launch energy, so the probe was launched on a Delta IV Heavy launch vehicle and an upper stage based on the Star 48BV solid rocket motor.[34] Interplanetary gravity assists will provide further deceleration relative to its heliocentric orbit, which will result in a heliocentric speed record at perihelion.[4][39] As the probe passes around the Sun, it will achieve a velocity of up to 200 km/s (120 mi/s), which will temporarily make it the fastest human-made object, almost three times as fast as the previous record holder, Helios-2.[40][41][42]

Launch injection was very close to the modelled one, but nevertheless required path correction. Trajectory was re-optimized after the launch to save the fuel. The first Venus flyby was only 52 days after the launch; three trajectory correction maneuvers were performed in this window.[20]

On September 27, 2023, the spacecraft traveled at 394,736 miles per hour (176.5 km/s), fast enough to fly from New York to Tokyo in just over a minute.[16] Like every object in an orbit, due to gravity the spacecraft will accelerate as it nears perihelion, then slow down again afterward until it reaches its aphelion.

Science goals

edit
 
An apparent size of the Sun as seen from the Parker Solar Probe at perihelion compared to its apparent size seen from Earth

The goals of the mission are:[34]

  • Trace the flow of energy that heats the solar corona and accelerates the solar wind.
    1. How is energy from the lower solar atmosphere transferred to, and dissipated in, the corona and solar wind?
    2. What processes shape the non-equilibrium velocity distributions observed throughout the heliosphere?
    3. How do the processes in the corona affect the properties of the solar wind in the heliosphere?
  • Determine the structure and dynamics of the plasma and magnetic fields at the sources of the solar wind.
    1. How does the magnetic field in the solar wind source regions connect to the photosphere and the heliosphere?
    2. Are the sources of the solar wind steady or intermittent?
    3. How do the observed structures in the corona evolve into the solar wind?
  • Explore mechanisms that accelerate and transport energetic particles.
    1. What are the roles of shocks, reconnection, waves, and turbulence in the acceleration of energetic particles?
    2. What are the source populations and physical conditions necessary for energetic particle acceleration?
    3. How are energetic particles transported in the corona and heliosphere?[34]

Instruments

edit
 
Schematic view of all PSP's instruments
 
Parker Solar Probe 3D model

Parker Solar Probe has four main instruments:[43][44]

  • FIELDS (Electromagnetic Fields Investigation). The instrument suite captures the scale and shape of electric and magnetic fields in the Sun's atmosphere. FIELDS measures waves and turbulence in the inner heliosphere with high time resolution to understand the fields associated with waves, shocks and magnetic reconnection, a process by which magnetic field lines explosively realign. FIELDS measures the electric field around the spacecraft with five antennas, four of which stick out beyond the spacecraft's heat shield and into the sunlight, where they experience temperatures of 2,500 °F (1,370 °C). The 2-meter-long (6 ft 7 in) antennas are made of a niobium alloy, which can withstand extreme temperatures. FIELDS measures electric fields across a broad frequency range both directly and remotely. Operating in two modes, the four sunlit antennas measure the properties of the fast and slow solar wind — the flow of solar particles constantly streaming out from the Sun. The fifth antenna, which sticks out perpendicular to the others in the shade of the heat shield, helps make a three-dimensional picture of the electric field at higher frequencies. The suite also has three magnetometers to assess the magnetic field. A search coil magnetometer, or SCM, measures how the magnetic field changes over time. Two identical fluxgate magnetometers, MAGi and MAGo, measure the large-scale coronal magnetic field. The fluxgate magnetometers are specialized for measuring the magnetic field further from the Sun where it varies at a slower rate, while the search coil magnetometer is necessary closer to the Sun where the field changes quickly, as it can sample the magnetic field at a rate of two million times per second. The Principal Investigator is Stuart Bale at the University of California, Berkeley.[43]
  • IS☉IS (Integrated Science Investigation of the Sun). The instrument uses two complementary instruments to measure particles across a wide range of energies. By measuring electrons, protons and ions, IS☉IS will understand the particles' lifecycles — where they came from, how they became accelerated and how they move out from the Sun through interplanetary space. The two energetic particle instruments on IS☉IS are called EPI-Lo and EPI-Hi (EPI stands for Energetic Particle Instrument). EPI-Lo measures the spectra of electrons and ions and identifies carbon, oxygen, neon, magnesium, silicon, iron and two isotopes of helium, He-3 and He-4. Distinguishing between helium isotopes will help determine which of several theorized mechanisms caused the particles' acceleration. The instrument has a design with an octagonal dome body supporting 80 viewfinders. Multiple viewfinders provide a wide field of view to observe low-energy particles. An ion that enters EPI-Lo through one of the viewfinders first passes through two carbon-polyimide-aluminum foils and then encounters a solid-state detector. Upon impact, the foils produce electrons, which are measured by a microchannel plate. Using the amount of energy left by the ion's impact on the detector and the time it takes the ions to pass through the sensor identifies the species of the particles. EPI-Hi uses three particle sensors composed of stacked layers of detectors to measure particles with energies higher than those measured by EPI-Lo. The front few layers are composed of ultra-thin silicon detectors made up of geometric segments, which allows for the determination of the particle's direction and helps reduce background noise. Charged particles are identified by measuring how deep they travel into the stack of detectors and how many electrons they pull off atoms in each detector, a process called ionization. At closest approach to the Sun, EPI-Hi will be able to detect up to 100,000 particles per second. The Principal Investigator is David McComas at Princeton University.[43][45]
  • WISPR (Wide-field Imager for Solar Probe). These optical telescopes acquire images of the corona and inner heliosphere. WISPR uses two cameras with radiation-hardened Active Pixel Sensor CMOS detectors. The camera's lenses are made of a radiation hard BK7, a common type of glass used for space telescopes, which is also sufficiently hardened against the impacts of dust. The Principal Investigator is Russell Howard at the Naval Research Laboratory.[43]
  • SWEAP (Solar Wind Electrons Alphas and Protons). This investigation will count the electrons, protons and helium ions, and measure their properties such as velocity, density, and temperature. Its main instruments are the Solar Probe Analyzers (SPAN, two electrostatic analyzers) and the Solar Probe Cup (SPC). SPC is a Faraday cup, a metal device that can catch charged particles in a vacuum. Peeking over the heat shield to measure how electrons and ions are moving, the cup is exposed to the full light, heat and energy of the Sun. The cup is composed of a series of highly transparent grids — one of which uses variable high voltages to sort the particles — above several collector plates, which measure the particles' properties. The variable voltage grid also helps sort out background noise, such as cosmic rays and photoionized electrons, which could otherwise bias the measurements. The grids, located near the front of the instrument, can reach temperatures of 3,000 °F (1,650 °C), glowing red while the instrument makes measurements. The instrument uses pieces of sapphire to electrically isolate different components within the cup. As it passes close to the Sun, SPC takes up to 146 measurements per second to accurately determine the velocity, density and temperature of the Sun's plasma. SPAN is composed of two instruments, SPAN-A and SPAN-B, which have wide fields of view to allow them to see the parts of space not observed by SPC. Particles encountering the detectors enter a maze that sends the particles through a series of deflectors and voltages to sort the particles based on their mass and charge. While SPAN-A has two components to measure both electrons and ions, SPAN-B looks only at electrons. The Principal Investigator is Justin Kasper at the University of Michigan and the Smithsonian Astrophysical Observatory.[43]

An additional theoretical investigation named Heliospheric origins with Solar Probe Plus (HeliOSPP) starting from 2010 and ending in 2024 has the role of providing theoretical input and independent assessment of scientific performance to the Science Working Group (SWG) and the SPP Project to maximize the scientific return from the mission. The Principal Investigator is Marco Velli at the University of California, Los Angeles and the Jet Propulsion Laboratory; he also serves as the Observatory Scientist for the mission.[34]

Mission

edit
 
Launch of the Parker Solar Probe in 2018
 
Artist's rendition of the Parker Solar Probe approaching the Sun

The Parker Solar Probe was launched on 12 August 2018, at 07:31 UTC. The spacecraft operated nominally after launching. During its first week in space it deployed its high-gain antenna, magnetometer boom, and electric field antennas.[46] The spacecraft performed its first scheduled trajectory correction on 20 August 2018, while it was 8.8 million kilometers (5.5 million mi) from Earth, and travelling at 63,569 kilometres per hour (39,500 mph)[47]

Instrument activation and testing began in early September 2018. On 9 September 2018, the two WISPR telescopic cameras performed a successful first-light test, transmitting wide-angle images of the background sky towards the galactic center.[48]

The probe successfully performed the first of the seven planned Venus flybys on 3 October 2018, where it came within about 2,400 kilometres (1,500 mi) of Venus in order to reduce the probe's speed and orbit closer to the Sun.[49]

 
The second flyby of Venus on December 26, 2019. The velocity decreases by 2.9 km/s to 26 km/s (red circle), shifting the spacecraft to a new orbit closer to the Sun.

Within each orbit of the Parker Solar Probe around the Sun, the portion within 0.25 AU is the Science Phase, in which the probe is actively and autonomously making observations. Communication with the probe is largely cut off in that phase.[50]: 4  Science phases run for a few days both before and after each perihelion. They lasted 11.6 days for the earliest perihelion, and will drop to 9.6 days for the final, closest perihelion.[50]: 8 

Much of the rest of each orbit is devoted to transmitting data from the science phase. But during this part of each orbit, there are still periods when communication is not possible. First, the requirement that the heat shield of the probe be pointed towards the Sun sometimes puts the heat shield between the antenna and Earth. Second, even when the probe is not particularly near the Sun, when the angle between the probe and the Sun, as seen from Earth, is too small, the Sun's radiation can overwhelm the communication link.[50]: 11–14 

After the first Venus flyby, the probe was in an elliptical orbit with a period of 150 days (two-thirds the period of Venus), making three orbits while Venus makes two. After the second flyby, the period shortened to 130 days. After less than two orbits, only 198 days later, it encountered Venus a third time at a point earlier in the orbit of Venus. This encounter shortened its period to half of that of Venus, or about 112.5 days. After two orbits it met Venus a fourth time at about the same place, shortening its period to about 102 days.[51]

After 237 days, it met Venus for the fifth time and its period was shortened to about 96 days, three-sevenths that of Venus. It then made seven orbits while Venus made three. The sixth encounter, almost two years after the fifth, shortened its period down to 92 days, two-fifths that of Venus. After five more orbits (two orbits of Venus), it will meet Venus for the seventh and last time, decreasing its period to 88 or 89 days and allowing it to approach closer to the Sun.[51]

Timeline

edit
The speed of the probe and distance from the Sun, from launch until 2026
List of events[51][34]: 31 [52]
Year Date Event Perihelion
distance (Gm)[a]
Speed
(km/s)
Orbital period
(days)
Notes
Flyby altitude
over Venus
[b]
Leg of
Parker's orbit
[c]
Inside/Outside
orbit of Venus
[d]
2018 12 August
07:31 UTC
Launch 151.6 174[e]
3 October
08:44 UTC
Venus flyby #1 2548 km[f] Inbound Inside Flybys 1 and 2 occur at the
same point in Venus's orbit
.
6 November
03:27 UTC
Perihelion #1 24.8[g] 95 150 Solar encounter phase
31 October – 11 November[55]
2019 4 April
22:40 UTC
Perihelion #2 Solar encounter phase
30 March – 10 April[56]
1 September
17:50 UTC[57]
Perihelion #3 Solar encounter phase
16 August – 20 September [h]
26 December
18:14 UTC[59]
Venus flyby #2 3023 km Inbound Inside Flybys 1 and 2 occur at the
same point in Venus's orbit
.
2020 29 January
09:37 UTC[60]
Perihelion #4 19.4 109 130 Solar encounter phase
23 January – 29 February[61]
7 June
08:23 UTC[62]
Perihelion #5 Solar encounter phase
9 May – 28 June[63]
11 July
03:22 UTC[64]
Venus flyby #3 834 km Outbound Outside[i] Flybys 3 and 4 occur at the
same point in Venus's orbit
.
27 September Perihelion #6 14.2 129 112.5
2021 17 January Perihelion #7
20 February Venus flyby #4 2392 km Outbound Outside Flybys 3 and 4 occur at the
same point in Venus's orbit
.
28 April Perihelion #8 11.1 147 102 First perihelion to enter the
solar corona
9 August Perihelion #9
16 October Venus flyby #5 3786 km Inbound Inside Flybys 5 and 6 occur at the
same point in Venus's orbit
.
21 November Perihelion #10 9.2 163 96
2022 25 February Perihelion #11
1 June Perihelion #12
6 September Perihelion #13
11 December Perihelion #14
2023 17 March Perihelion #15
22 June Perihelion #16
21 August Venus flyby #6 3939 km Inbound Inside Flybys 5 and 6 occur at the
same point in Venus's orbit
.
27 September Perihelion #17 7.9 176 92
29 December Perihelion #18
2024 30 March Perihelion #19
30 June Perihelion #20
30 September Perihelion #21
6 November Venus flyby #7 317 km Outbound Outside
24 December Perihelion #22 6.9 192 88
2025 22 March Perihelion #23
19 June Perihelion #24
15 September Perihelion #25
12 December Perihelion #26
  1. ^ For altitude above the surface, subtract one solar radius ≈0.7 Gm. (A Gm (gigametre) is a million km or about 621371 mi.)
  2. ^ Details on Venus flybys from Guo et al.[50]: 6  This was published in 2014, four years before the mission began. For a variety of reasons, including the fact that the launch had to be delayed at the last minute, actual details could differ from the ones presented in the work.
  3. ^ Inbound indicates that the Venus flyby will take place after Parker's aphelion (in the case of the first flyby, after its launch), on its way to perihelion. Outbound indicates that the Venus flyby will take place after Parker's perihelion, on its way to aphelion.
  4. ^ Inside indicates that the probe will pass in between Venus and the Sun. Outside indicates that the probe will pass beyond Venus from the Sun; the probe will briefly pass through Venus's shadow in those instances.
  5. ^ The first orbital period of 174 days was the orbit established by the launch and course adjustments, and was the orbit the probe would have taken had nothing further happened to change it. That orbit was, per mission plan, never completed. On the probe's first inbound course towards the Sun, it made its first planned encounter with Venus, which shortened its orbit considerably.
  6. ^ The altitude is from the source cited,[50]: 6  dated 2014. 2548 km comes to 1583 mi. NASA's [53] and Johns Hopkins's [54] press releases (identical), say "...came within about 1500 miles of Venus' surface..." A NASA blog,[49] says, "...completed its flyby of Venus at a distance of about 1500 miles..." Other news reports, presumably taking that information, also provide a figure of 2414 km. But neither the NASA/Hopkins press release nor the blog gives a figure in kilometers.
    Both the NASA and Hopkins press releases say that the flyby reduced the speed of the Parker Solar Probe (relative to the Sun) by about 10%, or 7000 mph. This altered the orbit, bringing perihelion about 4 million miles closer to the Sun than it would have been without the gravity assist.
  7. ^ By way of comparison, the planet Mercury orbits the Sun at a distance varying from about 46.0 Gm (46,001,200 km) at its closest to about 69.8 Gm (69,816,900 km) at its farthest.
  8. ^ After the second solar encounter phase, Parker Solar Probe was able to download much more data than NASA had expected. So NASA announced a substantial extension of the third solar encounter phase from 11 days to about 35 days. The observational instruments were turned on when Parker Solar Probe came within 0.45 au on the inbound trip, and are planned to run until the probe reaches about 0.50 au outbound.[58]
  9. ^ The third flyby of Venus was the first to pass behind Venus from the point of view of the Sun. The probe was in Venus's shadow, obscured from the Sun, for about 11 minutes, and passed through a so-called "tail" of Venus – a trail of charged particles from the atmosphere of Venus. The probe's instruments were to be turned on to make observations.[64]

Findings

edit
 
PSP observed switchbacks — traveling disturbances in the solar wind that caused the magnetic field to bend back on itself.
NASA animation of the Probe passing through the Sun's stellar corona. Inside the boundary at the corona's edge, its Alfvén critical surface, plasma connects to the Sun by waves traveling back and forth to the surface.

On November 6, 2018, Parker Solar Probe observed its first magnetic switchbacks – sudden reversals in the magnetic field of the solar wind.[65] They were first observed by the NASA-ESA mission Ulysses, the first spacecraft to fly over the Sun's poles.[66][67] The switchbacks generate heat that warms solar corona.[68]

On 4 December 2019, the first four research papers were published describing findings during the spacecraft's first two dives near the Sun.[69][70][71][72][73] They reported the direction and strength of the Sun's magnetic field, and described the unusually frequent and short-lived changes in the direction of the Sun's magnetic field. These measurements confirm the hypothesis that Alfvén waves are the leading candidates for understanding the mechanisms that underlie the coronal heating problem.[70][74] The probe observed approximately a thousand "rogue" magnetic waves in the solar atmosphere that instantly increase solar winds by as much as 300,000 miles per hour (480,000 km/h) and in some cases completely reverse the local magnetic field.[70][71][75][76]

They also reported that, using the "beam of electrons that stream along the magnetic field", they were able to observe that "the reversals in the Sun's magnetic field are often associated with localized enhancements in the radial component of the plasma velocity (the velocity in the direction away from the Sun's center)". The researchers found a "surprisingly large azimuthal component of the plasma velocity (the velocity perpendicular to the radial direction). This component results from the force with which the Sun's rotation slingshots plasma out of the corona when the plasma is released from the coronal magnetic field".[70][71]

PSP discovered evidence of a cosmic dust-free zone of 3.5 million miles (5.6 million kilometres) radius from the Sun, due to vaporisation of cosmic dust particles by the Sun's radiation.[77]

On April 28, 2021, during its eighth flyby of the Sun, Parker Solar Probe encountered the specific magnetic and particle conditions at 18.8 solar radii that indicated that it penetrated the Alfvén surface;[78][79] the probe measured the solar wind plasma environment with its FIELDS and SWEAP instruments.[80] This event was described by NASA as "touching the Sun".[78]

On 25 September 2022, the first discovery of a comet was made in images from the Parker Solar Probe. The comet is named PSP-001. It was found by Peter Berrett, who participates in the NASA funded Sungrazer project.[81] PSP-001 was discovered in images from 29 May 2022, part of the spacecraft's 12th approach to the Sun.

Since this discovery, a further 19 sungrazer comets have been discovered in the images taken by the Parker Solar Probe, including two non-group comets.

Designation Comet classification Image date Discovery date[82] Discoverer[82][83]
PSP-001 Kreutz 29 May 2022 25 Sep 2022 Peter Berrett
PSP-002 Kreutz 1 Sep 2022 N/A Karl Battams
PSP-003 Kreutz 2 Sep 2022 N/A Karl Battams
PSP-004 Kreutz 1 Sep 2022 N/A Karl Battams
PSP-005 Kreutz 18 Nov 2021 11 Feb 2023 Peter Berrett
PSP-006 Non Group 11 Dec 2022 13 May 2023 Peter Berrett
PSP-007 Kreutz 12 Mar 2023 12 Jul 2023 Karl Battams
PSP-008 Non Group 6 Dec 2022 16 Jul 2023 Rafał Biros
PSP-009 Kreutz 25 Apr 2021 28 Jul 2023 Rafał Biros
PSP-010 Kreutz 25 Apr 2021 28 Jul 2023 Rafał Biros
PSP-011 Kreutz 17 Nov 2021 24 Jul 2023 Rafał Biros
PSP-012 Kreutz 21 Feb 2022 30 Jul 2023 Rafał Biros
PSP-013 Kreutz 15 Feb 2022 27 Jul 2022 Peter Berrett
PSP-014 Kreutz 4 Aug 2021 3 Aug 2023 Rafał Biros
PSP-015 Kreutz 5–6 Aug 2021 3 Aug 2023 Rafał Biros
PSP-016 Kreutz 29 May 2022 4 Aug 2023 Rafał Biros
PSP-017 Kreutz 12 Jan 2021 16 Aug 2023 Robert Pickard
PSP-018 Kreutz 19 Jun 2023 13 Oct 2023 Peter Berrett
PSP-019 Non Group 27 Sep 2023 2 Nov 2023 Guillermo Stenborg
PSP-020 Kreutz 13 Jan 2021 8 Aug 2023 Peter Berrett

In 2024, it was reported that the probe detected a Kelvin-Helmholtz instability (KHI) during an observed coronal mass ejection. It is the first spacecraft that detected this long theorized event.[84]

PSP and Solar Orbiter collaboration

edit

PSP and ESA-NASA's Solar Orbiter (SolO) missions cooperated to trace solar wind and transients from their sources on the Sun to the inner interplanetary space.[85]

In 2022, PSP and SolO collaborated to study why the Sun's atmosphere is "150 times hotter" than its surface. SolO observed the Sun from 140 million kilometers, while PSP simultaneously observed the Sun's corona during flyby at a distance of nearly 9 million kilometers.[86][87]

In March 2024, both space probes were at their closest approach to the Sun, PSP at 7.3 million km, and SolO at 45 million km. SolO observed the Sun, while PSP sampled the plasma of solar wind, that allowed scientists to compare data from both probes.[88]

edit

See also

edit

Notes

edit
  1. ^ Mission planning used a perihelion of 9.5 R (6.6 Gm; 4.1×10^6 mi), or 8.5 R (5.9 Gm; 3.7×10^6 mi) altitude above the surface,[5] but later documents all say 9.86 R. The exact value will not be finalized until the seventh Venus gravity assist in 2024. Mission planners might decide to alter it slightly before then.

References

edit
  1. ^ a b c d Parker Solar Probe – Extreme Engineering Archived August 24, 2018, at the Wayback Machine. NASA.
  2. ^ a b Chang, Kenneth (August 12, 2018). "Parker Solar Probe Launches on NASA Voyage to 'Touch the Sun'". The New York Times. Archived from the original on December 24, 2021. Retrieved August 12, 2018.
  3. ^ "Parker Solar Probe Ready for Launch on Mission to the Sun". NASA. August 10, 2018. Archived from the original on March 8, 2021. Retrieved August 10, 2018.   This article incorporates text from this source, which is in the public domain.
  4. ^ a b Clark, Stephen (March 18, 2015). "Delta 4-Heavy selected for launch of solar probe". Spaceflight Now. Archived from the original on November 16, 2018. Retrieved March 18, 2015.
  5. ^ a b Applied Physics Laboratory (November 19, 2008). Feasible Mission Designs for Solar Probe Plus to Launch in 2015, 2016, 2017, or 2018 (PDF) (Report). Johns Hopkins University. Archived (PDF) from the original on December 21, 2021.   This article incorporates text from this source, which is in the public domain.
  6. ^ a b Clark, Stuart (July 22, 2018). "Parker Solar Probe: set the controls for the edge of the sun..." The Guardian. Archived from the original on December 3, 2020. Retrieved July 22, 2018.
  7. ^ a b "NASA Press Kit: Parker Solar Probe" (PDF). nasa.gov. NASA. August 2018. Archived (PDF) from the original on September 1, 2020. Retrieved August 15, 2018.   This article incorporates text from this source, which is in the public domain.
  8. ^ "Parker Solar Probe—eoPortal Directory—Satellite Missions". directory.eoportal.org. Archived from the original on July 1, 2017. Retrieved October 6, 2018.
  9. ^ Garner, Rob (August 9, 2018). "Parker Solar Probe: Humanity's First Visit to a Star". NASA. Archived from the original on June 5, 2017. Retrieved August 9, 2018.   This article incorporates text from this source, which is in the public domain.
  10. ^ "NASA solar probe becomes fastest object ever built as it 'touches the sun'". CNET. May 2, 2021. Retrieved June 17, 2022.
  11. ^ Bogel-Burroughs, Nicholas; Dunn, Marcia. "NASA probe operated from Johns Hopkins lab in Laurel rockets toward sun for closest look yet". The Baltimore Sun. Archived from the original on October 16, 2018. Retrieved August 16, 2018.
  12. ^ "NASA Renames Solar Probe Mission to Honor Pioneering Physicist Eugene Parker". NASA. May 31, 2017. Archived from the original on May 31, 2017. Retrieved May 31, 2017.   This article incorporates text from this source, which is in the public domain.
  13. ^ "More Than 1.1 Million Names Installed on NASA's Parker Solar Probe". NASA. May 21, 2018. Archived from the original on December 16, 2021. Retrieved December 17, 2021.
  14. ^ "NASA Press Kit: Parker Solar Probe". NASA. Archived from the original on July 1, 2017. Retrieved August 15, 2018.   This article incorporates text from this source, which is in the public domain.
  15. ^ Rogers, James (October 29, 2018). "NASA's Parker Solar Probe breaks record, becomes closest spacecraft to the Sun". Fox News. Archived from the original on March 25, 2021. Retrieved October 29, 2018.
  16. ^ a b Apodaca, Desiree (September 28, 2023). "For the Record: Parker Solar Probe Sets Distance, Speed Marks on 17th Swing by the Sun". blogs.nasa.gov. Retrieved October 12, 2023.
  17. ^ "Hey Nineteen! Parker Solar Probe Completes Record-Matching Sun Flyby". parkersolarprobe.jhuapl.edu. Retrieved May 12, 2024.
  18. ^ Naugle, John E. (1991). "3.2.2: Physics of Fields and Particles in Space". First Among Equals: The Selection of NASA Space Science Experiments (PDF). The NASA History Series. p. 34. LCCN 91-13286. NASA SP-4215. Archived (PDF) from the original on July 29, 2020. Retrieved February 11, 2020.   This article incorporates text from this source, which is in the public domain.
  19. ^ Bronk, Detlev W. (August 3, 1958). "National Academy of Sciences Establishes Space Science Board" (PDF) (Press release). National Academy of Sciences; National Research Council. Archived (PDF) from the original on March 3, 2019. Retrieved February 11, 2020.   This article incorporates text from this source, which is in the public domain.
  20. ^ a b Guo, Yanping; Thompson, Paul; Wirzburger, John; Pinkine, Nick; Bushman, Stewart; Goodson, Troy; Haw, Rob; Hudson, James; Jones, Drew; Kijewski, Seth; Lathrop, Brian; Lau, Eunice; Mottinger, Neil; Ryne, Mark; Shyong, Wen-Jong; Valerino, Powtawche; Whittenburg, Karl (February 2021). "Execution of Parker Solar Probe's unprecedented flight to the Sun and early results". Acta Astronautica. 179: 425–438. doi:10.1016/j.actaastro.2020.11.007.
  21. ^ a b McNutt, Ralph L. Jr. (December 15, 2015). Solar Probe Plus: A Scientific Investigation Sixty Years in the Making. American Geophysical Union Fall Meeting. Bibcode:2015AGUFMSH24A..01M. Archived from the original on September 25, 2021. Retrieved February 11, 2020.
  22. ^ Graber-Stiehl, Ian (August 13, 2018). "A 60-year race to touch the Sun". Astronomy. Archived from the original on January 24, 2020. Retrieved February 11, 2020.
  23. ^ "McNamee Chosen to Head NASA's Outer Planets/Solar Probe Projects" (Press release). Jet Propulsion Laboratory. April 15, 1998. Archived from the original on January 2, 2017. Retrieved January 2, 2017.
  24. ^ a b Maddock, Robert W.; Clark, Karla B.; Henry, Curt A.; Hoffman, Pamela J. (March 7, 1999). The Outer Planets/Solar Probe Project: "Between an ocean, a rock, and a hot place" (PDF). 1999 IEEE Aerospace Conference. Bibcode:1999aero....1..383M. Archived (PDF) from the original on May 11, 2019. Retrieved August 12, 2018.
  25. ^ a b Berger, Brian (February 4, 2002). "NASA Kills Europa Orbiter; Revamps Planetary Exploration". space.com. Purch Group. Archived from the original on February 10, 2002. Retrieved January 2, 2017.
  26. ^ Fazekas, Andrew (September 10, 2010). "New NASA Probe to Dive-bomb the Sun". National Geographic. 21st Century Fox/National Geographic Society. Archived from the original on January 2, 2017. Retrieved January 2, 2017.
  27. ^ Chang, Kenneth (August 10, 2018). "NASA's Parker Solar Probe Is Named for Him. 60 Years Ago, No One Believed His Ideas About the Sun". The New York Times. Archived from the original on August 11, 2018. Retrieved January 16, 2024. It is the Parker Solar Probe, named after Dr. Parker, now 91 years old. It is the first time that NASA has named a mission for a living person.
  28. ^ Burgess, Matt (May 31, 2017). "Nasa's mission to Sun renamed after astrophysicist behind solar wind theory". Wired. Archived from the original on November 25, 2020. Retrieved January 1, 2018.
  29. ^ Chhabra, Sherry (April 30, 2022). "Obituary: Eugene N. Parker (1927 - 2022)". SolarNews. Retrieved January 7, 2024.
  30. ^ "Eugene Parker, 'legendary figure' in solar science and namesake of Parker Solar Probe, 1927-2022 | University of Chicago News". news.uchicago.edu. March 16, 2022. Retrieved January 7, 2024.
  31. ^ How NASA's New Solar Probe Will 'Touch' the Sun on Historic Mission Archived January 27, 2021, at the Wayback Machine. Meghan Bartels, Space.com. August 9, 2018.
  32. ^ Successful Launch of NASA's Parker Solar Probe. Archived February 19, 2019, at the Wayback Machine SatNews Daily. August 12, 2018.
  33. ^ "Parker Solar Probe Begins Mission on Rocket Dedicated to APL's Andy Dantzler". The Johns Hopkins University Applied Physics Laboratory. September 26, 2018. Archived from the original on November 26, 2020. Retrieved December 3, 2018.
  34. ^ a b c d e f g Fox, N.J.; Velli, M.C.; Bale, S.D.; Decker, R.; Driesman, A.; Howard, R.A.; Kasper, J.C.; Kinnison, J.; Kusterer, M.; Lario, D.; Lockwood, M.K.; McComas, D.J.; Raouafi, N.E.; Szabo, A. (November 11, 2015). "The Solar Probe Plus Mission: Humanity's First Visit to Our Star". Space Science Reviews. 204 (1–4): 7–48. Bibcode:2016SSRv..204....7F. doi:10.1007/s11214-015-0211-6. ISSN 0038-6308.   Text was copied from this source, which is available under a Creative Commons Attribution 4.0 International License.
  35. ^ a b "Solar Probe Plus: A NASA Mission to Touch the Sun". Johns Hopkins University Applied Physics Laboratory. September 4, 2010. Archived from the original on March 1, 2021. Retrieved September 30, 2010.
  36. ^ a b "GMS: Cutting-Edge Heat Shield Installed on NASA's Parker Solar Probe". svs.gsfc.nasa.gov. July 5, 2018. Retrieved November 4, 2022.   This article incorporates text from this source, which is in the public domain.
  37. ^ Landis, Geoffrey A.; et al. (July 28–30, 2008). Solar Power System Design for the Solar Probe+ Mission (PDF). 6th International Energy Conversion Engineering Conference. Cleveland, Ohio. AIAA 2008-5712. Archived (PDF) from the original on November 11, 2020. Retrieved July 25, 2018.   This article incorporates text from this source, which is in the public domain.
  38. ^ Mehar, Pranjal (July 20, 2018). "Traveling to the Sun: Why won't Parker Solar Probe melt?". Tech Explorist. Archived from the original on December 29, 2019. Retrieved August 15, 2018.
  39. ^ Scharf, Caleb A. "The Fastest Spacecraft Ever?". Scientific American Blog Network. Archived from the original on December 27, 2021. Retrieved July 21, 2017.
  40. ^ "Aircraft Speed Records". Aerospaceweb.org. November 13, 2014. Archived from the original on December 23, 2018. Retrieved March 7, 2017.
  41. ^ "Fastest spacecraft speed". guinnessworldrecords.com. July 26, 2015. Archived from the original on December 19, 2016.
  42. ^ Parker Solar Probe – Check123, Video Encyclopedia, archived from the original on August 10, 2017, retrieved June 1, 2017
  43. ^ a b c d e Garner, Rob (July 12, 2018). "Parker Solar Probe Instruments". NASA. Archived from the original on August 11, 2018. Retrieved August 3, 2022.  This article incorporates text from this source, which is in the public domain.
  44. ^ "Parker Solar Probe: Spacecraft". parkersolarprobe.jhuapl.edu. Retrieved August 3, 2022.
  45. ^ McComas, D.J.; et al. (December 2016). "Integrated Science Investigation of the Sun (ISIS): Design of the Energetic Particle Investigation". Space Science Reviews. 204 (1–4): 187–156. Bibcode:2016SSRv..204..187M. doi:10.1007/s11214-014-0059-1.
  46. ^ "First milestones accomplished on NASA's newly-launched Parker Solar Probe – Spaceflight Now". spaceflightnow.com. Archived from the original on August 22, 2018. Retrieved August 22, 2018.
  47. ^ After Near-Perfect Trajectory Maneuver, Parker Solar Probe On Course To Touch The Sun Archived August 26, 2018, at the Wayback Machine. NASA. August 21, 2018   This article incorporates text from this source, which is in the public domain.
  48. ^ "Illuminating First Light Data from Parker Solar Probe". blogs.nasa.gov/parkersolarprobe. September 19, 2018. Archived from the original on September 22, 2018. Retrieved September 22, 2018.   This article incorporates text from this source, which is in the public domain.
  49. ^ a b "Parker Solar Probe Successfully Completes First Venus Flyby". blogs.nasa.gov/parkersolarprobe. NASA. October 3, 2018. Archived from the original on November 30, 2018. Retrieved December 26, 2018.   This article incorporates text from this source, which is in the public domain.
  50. ^ a b c d e Guo, Yanping; Ozimek, Martin; Mcadams, James; Shyong, Wen-Jong (May 2014). Solar Probe Plus Mission Design Overview and Mission Profile. International Symposium on Space Flight Dynamics, at Laurel, MD. ResearchGate. Archived from the original on May 2, 2022. Retrieved November 6, 2018.
  51. ^ a b c See data and figure at "Solar Probe Plus: The Mission". Johns Hopkins University Applied Physics Laboratory. 2017. Archived from the original on August 22, 2017. Retrieved June 17, 2017.   This article incorporates text from this source, which is in the public domain.
  52. ^ "HORIZONS System". Jet Propulsion Laboratory, NASA. Archived from the original on May 25, 2019. Retrieved August 16, 2018. Data file   This article incorporates text from this source, which is in the public domain.
  53. ^ "Parker Solar Probe Changed the Game Before it Even Launched". Parker Solar Probe News Center. Johns Hopkins University Applied Physics Laboratory. October 4, 2018. Archived from the original on October 6, 2018. Retrieved December 26, 2018.   This article incorporates text from this source, which is in the public domain.
  54. ^ "How A Change in Mission Design Unlocked the Journey to the Sun". Parker Solar Probe Mission News. NASA. October 4, 2018. Archived from the original on December 8, 2018. Retrieved December 26, 2018.   This article incorporates text from this source, which is in the public domain.
  55. ^ "Parker Solar Probe Reports First Telemetry, Acquisition of Science Data Since Perihelion". parkersolarprobe.jhuapl.edu. Johns Hopkins University Applied Physics Laboratory. November 20, 2018. Archived from the original on November 23, 2018. Retrieved December 18, 2018.
  56. ^ "NASA's Parker Solar Probe Makes Second Close Approach to Sun". sci-news.com. April 18, 2019. Archived from the original on April 10, 2019. Retrieved May 11, 2019.
  57. ^ Meghan Bartels (September 1, 2019). "NASA's Daring Solar Probe Is Skimming Past the Sun Today!". Space.com. Archived from the original on September 1, 2019. Retrieved September 2, 2019.
  58. ^ "Parker Solar Probe Gets Extra Observation Time". parkersolarprobe.jhuapl.edu. Johns Hopkins University Applied Physics Laboratory. August 16, 2018. Archived from the original on October 4, 2019. Retrieved September 2, 2018.   This article incorporates text from this source, which is in the public domain.
  59. ^ "Parker Solar Probe Heads Toward Second Venus Flyby". Parker Solar Probe News Center. Johns Hopkins University Applied Physics Laboratory. November 20, 2018. Archived from the original on December 26, 2019. Retrieved December 23, 2019. Gives the time as "1:14 p.m. EST" and the distance of the flyby as "within 1870 miles".   This article incorporates text from this source, which is in the public domain.
  60. ^ "Parker Solar Probe Completes Fourth Closest Approach, Breaks New Speed and Distance Records". Parker Solar Probe News Center. Johns Hopkins University Applied Physics Laboratory. January 29, 2020. Archived from the original on February 3, 2020. Retrieved February 21, 2020.   This article incorporates text from this source, which is in the public domain.
  61. ^ "Parker Solar Probe Reports Successful Record-Setting Fourth Close Encounter of the Sun". Parker Solar Probe News Center. Johns Hopkins University Applied Physics Laboratory. February 1, 2020. Archived from the original on February 3, 2020. Retrieved February 21, 2020.   This article incorporates text from this source, which is in the public domain.
  62. ^ Bartels, Meghan (June 7, 2020). "NASA's Parker Solar Probe flies by the sun in 5th close encounter". space.com. Future US Inc. Archived from the original on June 9, 2020. Retrieved June 11, 2020.
  63. ^ Surowiec, Justyna (May 12, 2020). "Parker Solar Probe Begins Longest Science Observation Campaign". parkersolarprobe.jhuapl.edu. Johns Hopkins University Applied Physics Laboratory. Archived from the original on June 12, 2020. Retrieved June 11, 2020.   This article incorporates text from this source, which is in the public domain.
  64. ^ a b Bartels, Meghan (July 10, 2020). "NASA's Parker Solar Probe swings through Venus 'tail' in flyby today". space.com. Future US Inc. Archived from the original on July 18, 2020. Retrieved July 18, 2020.
  65. ^ Hatfield, Miles (April 29, 2020). "New Insight Into Parker Solar Probe's Early Observations". NASA.  This article incorporates text from this source, which is in the public domain.
  66. ^ Hatfield, Miles (March 8, 2021). "Switchbacks Science: Explaining Parker Solar Probe's Magnetic Puzzle". NASA. Retrieved July 31, 2022.  This article incorporates text from this source, which is in the public domain.
  67. ^ Fisk, L. A.; Kasper, J. C. (May 1, 2020). "Global Circulation of the Open Magnetic Flux of the Sun". The Astrophysical Journal Letters. 894 (1): L4. Bibcode:2020ApJ...894L...4F. doi:10.3847/2041-8213/ab8acd.  Material was copied from this source, which is available under a Creative Commons Attribution 3.0
  68. ^ Zurbuchen, Thomas. "How a NASA Probe Solved a Scorching Solar Mystery". Quanta Magazine. Retrieved May 11, 2024.
  69. ^ Verscharen, Daniel (December 4, 2019). "A step closer to the Sun's secrets". Nature. 576 (7786): 219–220. Bibcode:2019Natur.576..219V. doi:10.1038/d41586-019-03665-3. PMID 31822830.
  70. ^ a b c d Chang, Kenneth (December 4, 2019). "NASA's Parker Solar Probe Is Unlocking the Sun's Mysteries". The New York Times. ISSN 0362-4331. Archived from the original on December 5, 2019. Retrieved January 16, 2024.
  71. ^ a b c Kasper, J. C.; Bale, S. D.; Belcher, J. W.; Berthomier, M.; Case, A. W.; Chandran, B. D. G.; Curtis, D. W.; Gallagher, D.; Gary, S. P.; Golub, L.; Halekas, J. S. (December 4, 2019). "Alfvénic velocity spikes and rotational flows in the near-Sun solar wind". Nature. 576 (7786): 228–231. Bibcode:2019Natur.576..228K. doi:10.1038/s41586-019-1813-z. hdl:10150/636481. ISSN 1476-4687. PMID 31802006. S2CID 208625853.
  72. ^ McComas, D. J.; Christian, E. R.; Cohen, C. M. S.; Cummings, A. C.; Davis, A. J.; Desai, M. I.; Giacalone, J.; Hill, M. E.; Joyce, C. J.; Krimigis, S. M.; Labrador, A. W. (December 4, 2019). "Probing the energetic particle environment near the Sun". Nature. 576 (7786): 223–227. Bibcode:2019Natur.576..223M. doi:10.1038/s41586-019-1811-1. ISSN 1476-4687. PMC 6908744. PMID 31802005.
  73. ^ Howard, R. A.; Vourlidas, A.; Bothmer, V.; Colaninno, R. C.; DeForest, C. E.; Gallagher, B.; Hall, J. R.; Hess, P.; Higginson, A. K.; Korendyke, C. M.; Kouloumvakos, A. (December 4, 2019). "Near-Sun observations of an F-corona decrease and K-corona fine structure". Nature. 576 (7786): 232–236. Bibcode:2019Natur.576..232H. doi:10.1038/s41586-019-1807-x. hdl:2268/242497. ISSN 1476-4687. PMID 31802002. S2CID 208620616. Archived from the original on June 25, 2020. Retrieved August 31, 2020.
  74. ^ Bale, S. D.; Badman, S. T.; Bonnell, J. W.; Bowen, T. A.; Burgess, D.; Case, A. W.; Cattell, C. A.; Chandran, B. D. G.; Chaston, C. C.; Chen, C. H. K.; Drake, J. F. (December 4, 2019). "Highly structured slow solar wind emerging from an equatorial coronal hole". Nature. 576 (7786): 237–242. Bibcode:2019Natur.576..237B. doi:10.1038/s41586-019-1818-7. hdl:11603/17219. ISSN 1476-4687. PMID 31802007. S2CID 208623434.
  75. ^ Witze, Alexandra (December 4, 2019). "Sun-bombing spacecraft uncovers secrets of the solar wind". Nature. 576 (7785): 15–16. Bibcode:2019Natur.576...15W. doi:10.1038/d41586-019-03684-0. PMID 31802020.
  76. ^ Drake, Nadia (December 4, 2019). "The sun keeps getting stranger, dive-bombing solar probe shows". National Geographic. Archived from the original on December 6, 2019. Retrieved December 6, 2019.
  77. ^ Tangermann, Victor (December 4, 2019). "Scientists 'Blown Away' by Unexpected Results From NASA's Sun-Kissing Solar Probe". ScienceAlert. Futurism. Archived from the original on December 16, 2019. Retrieved December 16, 2019.
  78. ^ a b Hatfield, Miles (December 13, 2021). "NASA Enters the Solar Atmosphere for the First Time". NASA.  This article incorporates text from this source, which is in the public domain.
  79. ^ "GMS: Animation: NASA's Parker Solar Probe Enters Solar Atmosphere". svs.gsfc.nasa.gov. December 14, 2021. Retrieved July 30, 2022.
  80. ^ "SVS: Parker Solar Probe: Crossing the Alfven Surface". svs.gsfc.nasa.gov. December 14, 2021. Retrieved July 30, 2022.  This article incorporates text from this source, which is in the public domain.
  81. ^ "Welcome to Sungrazer". sungrazer.nrl.navy.mil. Retrieved July 18, 2023.  This article incorporates text from this source, which is in the public domain.
  82. ^ a b "Parker Solar Probe (WISPR) Comets". sungrazer.nrl.navy.mil. Retrieved July 18, 2023.  This article incorporates text from this source, which is in the public domain.
  83. ^ "September 2023 and PSP confirmations". sungrazer.nrl.navy.mil. Retrieved November 16, 2023.  This article incorporates text from this source, which is in the public domain.
  84. ^ Paouris, Evangelos; Stenborg, Guillermo; Linton, Mark G.; Vourlidas, Angelos; Howard, Russell A.; Raouafi, Nour E. (2024). "First Direct Imaging of a Kelvin-Helmholtz Instability by PSP/WISPR". The Astrophysical Journal. 964 (2): 139. Bibcode:2024ApJ...964..139P. doi:10.3847/1538-4357/ad2208.
  85. ^ Biondo, Ruggero; et al. (December 2022). "Connecting Solar Orbiter remote-sensing observations and Parker Solar Probe in situ measurements with a numerical MHD reconstruction of the Parker spiral". Astronomy & Astrophysics. 668: A144. arXiv:2211.12994. Bibcode:2022A&A...668A.144B. doi:10.1051/0004-6361/202244535.   This article incorporates text from this source, which is available under the CC BY 4.0 license.
  86. ^ Skibba, Ramin. "A Pair of Sun Probes Just Got Closer to Solving a Solar Enigma". Wired. Archived from the original on September 20, 2023. Retrieved March 30, 2024.
  87. ^ Telloni, Daniele; et al. (September 1, 2023). "Coronal Heating Rate in the Slow Solar Wind". The Astrophysical Journal Letters. 955 (1): L4. arXiv:2306.10819. Bibcode:2023ApJ...955L...4T. doi:10.3847/2041-8213/ace112.
  88. ^ "ESA and NASA team up to study solar wind". www.esa.int. Retrieved March 30, 2024.
  89. ^ Frazier, Sarah; Surowiec, Justyna (September 19, 2018). "Illuminating First Light Data from Parker Solar Probe". Johns Hopkins University Applied Physics Laboratory. Archived from the original on December 30, 2021. Retrieved September 22, 2018.
  90. ^ Garner, Rob (October 22, 2018). "Parker Solar Probe Looks Back at Home". NASA. Archived from the original on April 29, 2022. Retrieved April 29, 2022.
  91. ^ "Preparing for Discovery With NASA's Parker Solar Probe". Parker Solar Probe. Johns Hopkins University Applied Physics Laboratory. Archived from the original on February 14, 2022. Retrieved December 23, 2018.
  92. ^ Buckley, Mike. "Parker Solar Probe Captures a Planetary Portrait". Parker Solar Probe. Johns Hopkins APL. Archived from the original on April 29, 2022. Retrieved April 29, 2022.
  93. ^ Hatfield, Miles (February 9, 2022). "Parker Solar Probe Captures Visible Light Images of Venus' Surface". NASA. Archived from the original on April 14, 2022. Retrieved April 29, 2022.
  94. ^ Wood, B. E.; Hess, P.; Lustig-Yaeger, J.; Gallagher, B.; Korwan, D.; Rich, N.; Stenborg, G.; Thernisien, A.; Qadri, S. N.; Santiago, F.; Peralta, J.; Arney, G. N.; Izenberg, N. R.; Vourlidas, A.; Linton, M. G.; Howard, R. A.; Raouafi, N. E. (February 9, 2022). "Parker Solar Probe Imaging of the Night Side of Venus". Geophysical Research Letters. 49 (3): e2021GL096302. Bibcode:2022GeoRL..4996302W. doi:10.1029/2021GL096302. PMC 9286398. PMID 35864851.

Further reading

edit
edit