planetary surface

Planetary surfaces are found throughout the Solar System, from the inner terrestrial planets, to the asteroid belt, the natural satellites of the giant planets and beyond to the Trans-Neptunian objects. Surface conditions, temperatures and terrain vary significantly due to a number of factors including Albedo often generated by the surfaces itself. Measures of surface conditions include surface area, surface gravity, surface temperature and surface pressure. Surface stability may be affected by erosion through Aeolian processes, hydrology, subduction, volcanism, sediment or seismic activity. Some surfaces are dynamic while others remain unchanged for millions of years.

File:HSF 0163 0681410921 308ECM N0110001HELI00000 000085J Perseverance Spotted By Ingenuity's colour camera On Its 11th Flight.gif on Mars, hovering over its serface and being watched by its parent rover Perseverance rover.]]

Distance, gravity, atmospheric conditions (extremely low or extremely high atmospheric pressure) and unknown factors make exploration both costly and risky. This necessitates the space probes for early exploration of planetary surfaces. Many probes are stationary have a limited study range and generally survive on extraterrestrial surfaces for a short period, however mobile probes (rovers) have surveyed larger surface areas. Sample return missions allow scientist to study extraterrestrial surface materials on Earth without having to send a crewed mission, however is generally only feasible for objects with low gravity and atmosphere.

{{More citations needed section|date=September 2020}}

The first extraterrestrial planetary surface to be explored was the lunar surface by Luna 2 in 1959. The first and only human exploration of an extraterrestrial surface was the Moon, the Apollo program included the first moonwalk on July 20, 1969, and successful return of extraterrestrial surface samples to Earth. Venera 7 was the first landing of a probe on another planet on December 15, 1970. Mars 3 "soft landed" and returned data from Mars on August 22, 1972, the first rover on Mars was Mars Pathfinder in 1997, the Mars Exploration Rover has been studying the surface of the red planet since 2004. NEAR Shoemaker was the first to soft land on an asteroid – 433 Eros in February 2001 while Hayabusa was the first to return samples from 25143 Itokawa on 13 June 2010. Huygens soft landed and returned data from Titan on January 14, 2005.

There have been many failed attempts, more recently Fobos-Grunt, a sample return mission aimed at exploring the surface of Phobos.

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|File:Foto de Venera 9.png

|alt1=Venera 9 returned the first view and this first clear image from the surface of another planet in 1975 (Venus).{{cite web |title=Venera 9's landing site |url=https://www.planetary.org/space-images/20120907_venera_9_panorama_stryk |website=The Planetary Society |access-date=16 September 2020 |language=en}}

|Venera 9 returned the first view and this first clear image from the surface of another planet in 1975 (Venus).{{cite web |title=Venera 9's landing site |url=https://www.planetary.org/space-images/20120907_venera_9_panorama_stryk |website=The Planetary Society |access-date=16 September 2020 |language=en}}

}}

The surfaces of Solar System objects, other than the four Outer Solar System giant planets, are mostly solid, with few having liquid surfaces.

In general terrestrial planets have either surfaces of ice, or surface crusts of rock or regolith, with distinct terrains.

Water ice predominates surfaces in the Solar System beyond the frost line in the Outer Solar System, with a range of icy celestial bodies. Rock and regolith is common in the Inner Solar System until Mars.

The only Solar System object having a mostly liquid surface is Earth, with its global ocean surface comprising 70.8 % of Earth's surface, filling its oceanic basins and covering Earth's oceanic crust, making Earth an ocean world. The remaining part of its surface consists of rocky or organic carbon and silicon rich compounds.

File:Liquid lakes on titan.jpg (lower right) and other northern hemisphere hydrocarbon lakes]]

Liquid water as surface, beside on Earth, has only been found, as seasonal flows on warm Martian slopes, as well as past occurrences, and suspected at the habitable zones of other planetary systems.

Surface liquid of any kind, has been found notably on Titan, having large methane lakes, some of which are the largest known lakes in the Solar System.

Volcanism can cause flows such as lava on the surface of geologically active bodies (the largest being the Amirani (volcano) flow on Io). Many of Earth's Igneous rocks are formed through processes rare elsewhere, such as the presence of volcanic magma and water. Surface mineral deposits such as olivine and hematite discovered on Mars by lunar rovers provide direct evidence of past stable water on the surface of Mars.

Apart from water, many other abundant surface materials are unique to Earth in the Solar System as they are not only organic but have formed due to the presence of life – these include carbonate hardgrounds, limestone, vegetation and artificial structures although the latter is present due to probe exploration (see also List of artificial objects on extra-terrestrial surfaces).

Increasingly organic compounds are being found on objects throughout the Solar System. While unlikely to indicate the presence of extraterrestrial life, all known life is based on these compounds. Complex carbon molecules may form through various complex chemical interactions or delivered through impacts with small solar system objects and can combine to form the "building blocks" of Carbon-based life. As organic compounds are often volatile, their persistence as a solid or liquid on a planetary surface is of scientific interest as it would indicate an intrinsic source (such as from the object's interior) or residue from larger quantities of organic material preserved through special circumstances over geological timescales, or an extrinsic source (such as from past or recent collision with other objects).{{cite journal|last1=Ehrenfreund|first1=P.|last2=Spaans|first2=M.|last3=Holm|first3=N. G.|title=The evolution of organic matter in space|journal=Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences|volume=369|issue=1936|year=2011|pages=538–554|doi=10.1098/rsta.2010.0231|pmid=21220279|bibcode=2011RSPTA.369..538E|doi-access=free}} Radiation makes the detection of organic matter difficult, making its detection on atmosphereless objects closer to the Sun extremely difficult.{{cite journal|last1=Anders|first1=Edward|title=Pre-biotic organic matter from comets and asteroids|journal=Nature|volume=342|issue=6247|year=1989|pages=255–257|doi=10.1038/342255a0|pmid=11536617|bibcode=1989Natur.342..255A|s2cid=4242121}}

Examples of likely occurrences include:

• Tholins – many Trans Neptunian Objects including Pluto-Charon,{{cite journal|last1=Grundy|first1=W. M.|last2=Cruikshank|first2=D. P.|last3=Gladstone|first3=G. R.|last4=Howett|first4=C. J. A.|last5=Lauer|first5=T. R.|last6=Spencer|first6=J. R.|last7=Summers|first7=M. E.|last8=Buie|first8=M. W.|last9=Earle|first9=A. M.|last10=Ennico|first10=K.|last11=Parker|first11=J. Wm.|last12=Porter|first12=S. B.|last13=Singer|first13=K. N.|last14=Stern|first14=S. A.|last15=Verbiscer|first15=A. J.|last16=Beyer|first16=R. A.|last17=Binzel|first17=R. P.|last18=Buratti|first18=B. J.|last19=Cook|first19=J. C.|last20=Dalle Ore|first20=C. M.|author20-link=Cristina Dalle Ore|last21=Olkin|first21=C. B.|last22=Parker|first22=A. H.|last23=Protopapa|first23=S.|last24=Quirico|first24=E.|last25=Retherford|first25=K. D.|last26=Robbins|first26=S. J.|last27=Schmitt|first27=B.|last28=Stansberry|first28=J. A.|last29=Umurhan|first29=O. M.|last30=Weaver|first30=H. A.|last31=Young|first31=L. A.|last32=Zangari|first32=A. M.|last33=Bray|first33=V. J.|last34=Cheng|first34=A. F.|last35=McKinnon|first35=W. B.|last36=McNutt|first36=R. L.|last37=Moore|first37=J. M.|last38=Nimmo|first38=F.|last39=Reuter|first39=D. C.|last40=Schenk|first40=P. M.|last41=Stern|first41=S. A.|last42=Bagenal|first42=F.|last43=Ennico|first43=K.|last44=Gladstone|first44=G. R.|last45=Grundy|first45=W. M.|last46=McKinnon|first46=W. B.|last47=Moore|first47=J. M.|last48=Olkin|first48=C. B.|last49=Spencer|first49=J. R.|last50=Weaver|first50=H. A.|last51=Young|first51=L. A.|last52=Andert|first52=T.|last53=Barnouin|first53=O.|last54=Beyer|first54=R. A.|last55=Binzel|first55=R. P.|last56=Bird|first56=M.|last57=Bray|first57=V. J.|last58=Brozović|first58=M.|last59=Buie|first59=M. W.|last60=Buratti|first60=B. J.|last61=Cheng|first61=A. F.|last62=Cook|first62=J. C.|last63=Cruikshank|first63=D. P.|last64=Dalle Ore|first64=C. M.|author64-link=Cristina Dalle Ore|last65=Earle|first65=A. M.|last66=Elliott|first66=H. A.|last67=Greathouse|first67=T. K.|last68=Hahn|first68=M.|last69=Hamilton|first69=D. P.|last70=Hill|first70=M. E.|last71=Hinson|first71=D. P.|last72=Hofgartner|first72=J.|last73=Horányi|first73=M.|last74=Howard|first74=A. D.|last75=Howett|first75=C. J. A.|last76=Jennings|first76=D. E.|last77=Kammer|first77=J. A.|last78=Kollmann|first78=P.|last79=Lauer|first79=T. R.|last80=Lavvas|first80=P.|last81=Linscott|first81=I. R.|last82=Lisse|first82=C. M.|last83=Lunsford|first83=A. W.|last84=McComas|first84=D. J.|last85=McNutt Jr.|first85=R. L.|last86=Mutchler|first86=M.|last87=Nimmo|first87=F.|last88=Nunez|first88=J. I.|last89=Paetzold|first89=M.|last90=Parker|first90=A. H.|last91=Wm. Parker|first91=J.|last92=Philippe|first92=S.|last93=Piquette|first93=M.|last94=Porter|first94=S. B.|last95=Protopapa|first95=S.|last96=Quirico|first96=E.|last97=Reitsema|first97=H. J.|last98=Reuter|first98=D. C.|last99=Robbins|first99=S. J.|last100=Roberts|first100=J. H.|last101=Runyon|first101=K.|last102=Schenk|first102=P. M.|last103=Schindhelm|first103=E.|last104=Schmitt|first104=B.|last105=Showalter|first105=M. R.|last106=Singer|first106=K. N.|last107=Stansberry|first107=J. A.|last108=Steffl|first108=A. J.|last109=Strobel|first109=D. F.|last110=Stryk|first110=T.|last111=Summers|first111=M. E.|last112=Szalay|first112=J. R.|last113=Throop|first113=H. B.|last114=Tsang|first114=C. C. C.|last115=Tyler|first115=G. L.|last116=Umurhan|first116=O. M.|last117=Verbiscer|first117=A. J.|last118=Versteeg|first118=M. H.|last119=Weigle II|first119=G. E.|last120=White|first120=O. L.|last121=Woods|first121=W. W.|last122=Young|first122=E. F.|last123=Zangari|first123=A. M.|title=The formation of Charon's red poles from seasonally cold-trapped volatiles|journal=Nature|volume=539|issue=7627|year=2016|pages=65–68|doi=10.1038/nature19340|pmid=27626378|bibcode=2016Natur.539...65G|display-authors=29|arxiv=1903.03724|s2cid=205250398}} Titan,{{cite journal |last1=McCord |first1=T. B. |last2=Hansen |first2=G. B. |last3=Buratti |first3=B. J. |last4=Clark |first4=R. N. |last5=Cruikshank |first5=D. P. |last6=D’Aversa |first6=E. |last7=Griffith |first7=C. A. |last8=Baines |first8=E. K. H. |last9=Brown |first9=R. H. |last10=Dalle Ore |first10=C. M.|author10-link=Cristina Dalle Ore |last11=Filacchione |first11=G. |last12=Formisano |first12=V. |last13=Hibbitts |first13=C. A. |last14=Jaumann |first14=R. |last15=Lunine |first15=Jonathan I. |last16=Nelson |first16=R. M. |last17=Sotin |first17=C. |title=Composition of Titan's surface from Cassini VIMS |journal=Planetary and Space Science |volume=54 |issue=15 |year=2006 |pages=1524–1539 |doi=10.1016/j.pss.2006.06.007 |bibcode=2006P&SS...54.1524M }} Triton,{{cite journal |last1=Grundy |first1=W. M. |last2=Buie |first2=M. W. |last3=Spencer |first3=J. R. |title=Spectroscopy of Pluto and Triton at 3–4 Microns: Possible Evidence for Wide Distribution of Nonvolatile Solids |journal=The Astronomical Journal |volume=124 |issue=4 |pages=2273–2278 |date=October 2002 |doi=10.1086/342933 |bibcode=2002AJ....124.2273G |doi-access=free }} Eris,{{cite journal

| title = Discovery of a Planetary-sized Object in the Scattered Kuiper Belt

| author = Brown, Michael E., Trujillo, Chadwick A., Rabinowitz, David L.

| journal = The Astrophysical Journal

| date = 2005

| volume = 635

| issue = 1

| pages = L97–L100

| doi = 10.1086/499336

| arxiv = astro-ph/0508633

| bibcode = 2005ApJ...635L..97B

| s2cid = 1761936

}} Sedna,{{cite journal

| title = Is Sedna another Triton?

| journal = Astronomy & Astrophysics

| volume = 439

| issue = 2

| year = 2005

| pages = L1–L4

| doi = 10.1051/0004-6361:200500144

| bibcode = 2005A&A...439L...1B

| last1 = Barucci

| first1 = M. A.

| last2 = Cruikshank

| first2 = D. P.

| last3 = Dotto

| first3 = E.

| last4 = Merlin

| first4 = F.

| last5 = Poulet

| first5 = F.

| last6 = Dalle Ore

| first6 = C.|author6-link=Cristina Dalle Ore

| last7 = Fornasier

| first7 = S.

| last8 = De Bergh

| first8 = C.

| doi-access = free

}} 28978 Ixion,{{cite journal

|date=2004

|title=Surface characterization of 28978 Ixion (2001 KX76)

|journal=Astronomy and Astrophysics Letters

|volume=415 |pages=L21–L25

|doi=10.1051/0004-6361:20040005

|bibcode=2004A&A...415L..21B

|display-authors=1

|issue=2

|last1=Boehnhardt

|first1=H.

|last2=Bagnulo

|first2=S.

|last3=Muinonen

|first3=K.

|last4=Barucci

|first4=M. A.

|last5=Kolokolova

|first5=L.

|last6=Dotto

|first6=E.

|last7=Tozzi

|first7=G. P.

|doi-access=free

}} 90482 Orcus,{{cite journal

| first = C.

| last = de Bergh

| title = The Surface of the Transneptunian Object 9048 Orcus

| journal = Astronomy & Astrophysics

| volume = 437

| issue = 3

| date = 2005

| pages = 1115–20

| bibcode = 2005A&A...437.1115D

| doi = 10.1051/0004-6361:20042533

| doi-access = free

}} 24 Themis{{cite journal |last1=Omar |first1=M. H. |last2=Dokoupil |first2=Z. |title=Solubility of nitrogen and oxygen in liquid hydrogen at temperatures between 27 and 33K |journal=Physica |date=May 1962 |volume=28 |issue=5 |pages=461–471 |doi=10.1016/0031-8914(62)90033-2 |bibcode=1962Phy....28..461O }}{{Cite journal |last1=Rivkin |first1=Andrew S. |last2=Emery |first2=Joshua P. |title=Detection of ice and organics on an asteroidal surface |journal=Nature |volume=464 |issue=7293 |pages=1322–1323 |date=2010 |doi=10.1038/nature09028 |pmid=20428165 |bibcode = 2010Natur.464.1322R |s2cid=4368093 }} ([http://somosbacteriasyvirus.com/surface.pdf pdf version] accessed 28 Feb. 2018).

• Methane clathrate (CH₄·5.75H₂O) – Oberon, Titania, Umbriel, Pluto, 90482 Orcus, Comet 67P

Martian exploration including samples taken by on the ground rovers and spectroscopy from orbiting satellites have revealed the presence of a number of complex organic molecules, some of which could be biosignatures in the search for life.

• Thiophene ({{chem|C|4|H|4|S}}){{cite journal|last1=Voosen|first1=Paul|title=NASA rover hits organic pay dirt on Mars|journal=Science|year=2018|doi=10.1126/science.aau3992|s2cid=115442477 }}
• Polythiophene (polymer of {{chem|C|4|H|4|S}}){{cite journal|last1=Mukbaniani|first1=O. V.|last2=Aneli|first2=J. N.|last3=Markarashvili|first3=E. G.|last4=Tarasashvili|first4=M. V.|last5=Aleksidze|first5=N. D.|title=Polymeric composites on the basis of Martian ground for building future mars stations|journal=International Journal of Astrobiology|volume=15|issue=2|year=2015|pages=155–160|issn=1473-5504|doi=10.1017/S1473550415000270|s2cid=123421464 }}
• Methanethiol ({{chem|CH|3|SH}}){{cite journal|last1=Eigenbrode|first1=Jennifer L.|last2=Summons|first2=Roger E.|last3=Steele|first3=Andrew|last4=Freissinet|first4=Caroline|last5=Millan|first5=Maëva|last6=Navarro-González|first6=Rafael|last7=Sutter|first7=Brad|last8=McAdam|first8=Amy C.|last9=Franz|first9=Heather B.|last10=Glavin|first10=Daniel P.|last11=Archer|first11=Paul D.|last12=Mahaffy|first12=Paul R.|last13=Conrad|first13=Pamela G.|last14=Hurowitz|first14=Joel A.|last15=Grotzinger|first15=John P.|last16=Gupta|first16=Sanjeev|last17=Ming|first17=Doug W.|last18=Sumner|first18=Dawn Y.|last19=Szopa|first19=Cyril|last20=Malespin|first20=Charles|last21=Buch|first21=Arnaud|last22=Coll|first22=Patrice|title=Organic matter preserved in 3-billion-year-old mudstones at Gale crater, Mars|journal=Science|volume=360|issue=6393|year=2018|pages=1096–1101|issn=0036-8075|doi=10.1126/science.aas9185|pmid=29880683|bibcode=2018Sci...360.1096E|s2cid=46983230|url=http://spiral.imperial.ac.uk/bitstream/10044/1/60810/2/aas9185_CombinedPDF_v2.pdf|doi-access=free}}
• Dimethyl sulfide ({{chem|CH|2|S}})

• Ammonium bicarbonate ({{chem|N|H|4|H|C|O|3}}).{{cite journal|doi=10.1016/j.pss.2017.04.014|title=Preferential formation of sodium salts from frozen sodium-ammonium-chloride-carbonate brines – Implications for Ceres' bright spots|journal=Planetary and Space Science|volume=141|pages=73–77|year=2017|last1=Vu|first1=Tuan H|last2=Hodyss|first2=Robert|last3=Johnson|first3=Paul V|last4=Choukroun|first4=Mathieu|bibcode=2017P&SS..141...73V}}{{cite journal|doi=10.1016/j.icarus.2018.03.004|title=The surface composition of Ceres from the Dawn mission|journal=Icarus|volume=318|pages=2–13|year=2018|last1=McCord|first1=Thomas B|last2=Zambon|first2=Francesca|bibcode=2019Icar..318....2M|s2cid=125115208 }}
• Gilsonite{{cite journal|last1=De Sanctis|first1=M. C.|last2=Ammannito|first2=E.|last3=McSween|first3=H. Y.|last4=Raponi|first4=A.|last5=Marchi|first5=S.|last6=Capaccioni|first6=F.|last7=Capria|first7=M. T.|last8=Carrozzo|first8=F. G.|last9=Ciarniello|first9=M.|last10=Fonte|first10=S.|last11=Formisano|first11=M.|last12=Frigeri|first12=A.|last13=Giardino|first13=M.|last14=Longobardo|first14=A.|last15=Magni|first15=G.|last16=McFadden|first16=L. A.|last17=Palomba|first17=E.|last18=Pieters|first18=C. M.|last19=Tosi|first19=F.|last20=Zambon|first20=F.|last21=Raymond|first21=C. A.|last22=Russell|first22=C. T.|title=Localized aliphatic organic material on the surface of Ceres|journal=Science|volume=355|issue=6326|year=2017|pages=719–722|doi=10.1126/science.aaj2305|pmid=28209893|bibcode=2017Sci...355..719D|s2cid=16758552}}

• Methylamine/Ethylamine{{cite journal|last1=Khawaja|first1=N|last2=Postberg|first2=F|last3=Hillier|first3=J|last4=Klenner|first4=F|last5=Kempf|first5=S|last6=Nölle|first6=L|last7=Reviol|first7=R|last8=Zou|first8=Z|last9=Srama|first9=R|title=Low-mass nitrogen-, oxygen-bearing, and aromatic compounds in Enceladean ice grains|journal=Monthly Notices of the Royal Astronomical Society|volume=489|issue=4|year=2019|pages=5231–5243|issn=0035-8711|doi=10.1093/mnras/stz2280|bibcode=2019MNRAS.489.5231K|doi-access=free}} (CH₃ NH₂)
• Acetaldehyde (CH₃ CHO)

The space probe Philae (spacecraft) discovered the following organic compounds on the surface of Comet 67P:.{{cite news |url=https://www.washingtonpost.com/world/philae-probe-finds-evidence-that-comets-can-be-cosmic-labs/2015/07/30/63a2fc0e-36e5-11e5-ab7b-6416d97c73c2_story.html |archive-url=https://web.archive.org/web/20181223235109/https://www.washingtonpost.com/world/philae-probe-finds-evidence-that-comets-can-be-cosmic-labs/2015/07/30/63a2fc0e-36e5-11e5-ab7b-6416d97c73c2_story.html |url-status=dead |archive-date=23 December 2018 |title=Philae probe finds evidence that comets can be cosmic labs |newspaper=The Washington Post |agency=Associated Press |first=Frank |last=Jordans |date=30 July 2015 |access-date=30 July 2015}}{{cite web |url=http://www.esa.int/Our_Activities/Space_Science/Rosetta/Science_on_the_surface_of_a_comet |title=Science on the Surface of a Comet |publisher=European Space Agency |date=30 July 2015 |access-date=30 July 2015}}{{cite journal |last1=Bibring |first1=J.-P. |last2=Taylor |first2=M.G.G.T. |last3=Alexander |first3=C. |last4=Auster |first4=U. |last5=Biele |first5=J. |last6=Finzi |first6=A. Ercoli |last7=Goesmann |first7=F. |last8=Klingehoefer |first8=G. |last9=Kofman |first9=W. |last10=Mottola |first10=S. |last11=Seidenstiker |first11=K.J. |last12=Spohn |first12=T. |last13=Wright |first13=I. |title=Philae's First Days on the Comet – Introduction to Special Issue |date=31 July 2015 |journal=Science |volume=349 |issue=6247 |page=493 |doi=10.1126/science.aac5116 |bibcode=2015Sci...349..493B |pmid=26228139|doi-access=free }}

• Acetamide ({{chem|CH|3|CONH|2}})
• Acetone (CH₃)₂CO
• Methyl isocyanate ({{chem|CH|3|NCO}})
• Propionaldehyde ({{chem|CH|3|CH|2|CHO}})

File:Titan dunes crop.png on Earth (top), compared with dunes in Belet on Titan]]

The following is a non-exhaustive list of surface materials that occur on more than one planetary surface along with their locations in order of distance from the Sun. Some have been detected by spectroscopy or direct imaging from orbit or flyby.

• Ice ({{chem|H|2|O}}) – Mercury (polar); Earth-Moon system;{{cite web|url=http://nssdc.gsfc.nasa.gov/planetary/ice/ice_moon.html |title=Ice on the Moon |publisher=NASA|date=10 December 2012 |author=Williams, David R. }} Mars (polar); CeresChoi, Charles Q. (December 15, 2016) [http://www.space.com/35035-water-on-ceres-in-permanent-shadow.html Water Ice Found On Dwarf Planet Ceres, Hidden in Permanent Shadow]. Space.com] and some asteroids such as 24 Themis;{{cite web|last=Moskowitz |first=Clara |url=http://www.space.com/8305-water-ice-discovered-asteroid-time.html |title=Water Ice Discovered on Asteroid for First Time |publisher=Space.com |date=2010-04-28 |access-date=2018-08-20}} Jupiter moons – Europa,{{cite web |url=http://teachspacescience.org/cgi-bin/search.plex?catid=10000304&mode=full |title=Europa: Another Water World? |date=2001 |access-date=9 August 2007 |publisher=NASA, Jet Propulsion Laboratory |work=Project Galileo: Moons and Rings of Jupiter |url-status=dead |archive-url=https://web.archive.org/web/20110721210346/http://teachspacescience.org/cgi-bin/search.plex?catid=10000304&mode=full |archive-date=21 July 2011 }} Ganymede and Callisto; Triton,; Saturn moons – Titan and Enceladus; Uranus moons – Miranda, Umbriel, Oberon; Kuiper belt objects including Pluto-Charon system, Haumea, 28978 Ixion, 90482 Orcus, 50000 Quaoar
• Silicate rock – Mercury, Venus, Earth, Mars, asteroids, Ganymede, Callisto, Moon, Triton
• Regolith – Mercury;{{cite journal | bibcode = 1997P&SS...45...31L | title=The regolith of Mercury: present knowledge and implications for the Mercury Orbiter mission | journal=Planetary and Space Science | volume=45 | issue=1 | pages=31–37 | year=1997 | doi=10.1016/s0032-0633(96)00098-0| last1=Langevin | first1=Y }} Venus,{{cite book|author1=Scott, Keith |author2=Pain, Colin |title=Regolith Science|url=https://books.google.com/books?id=mo-MUnoPmN4C&pg=PA390|date=18 August 2009|publisher=Csiro Publishing|isbn=978-0-643-09996-8|pages=390–}} Earth-Moon system; Mars (and its moons Phobos and Deimos); asteroids (including 4 Vesta{{Cite journal | last1 = Pieters | first1 = C. M. | last2 = Ammannito | first2 = E. | last3 = Blewett | first3 = D. T. | last4 = Denevi | first4 = B. W. | last5 = De Sanctis | first5 = M. C. | last6 = Gaffey | first6 = M. J. | last7 = Le Corre | first7 = L. | last8 = Li | first8 = J. -Y. | last9 = Marchi | first9 = S. | last10 = McCord | doi = 10.1038/nature11534 | first10 = T. B. | last11 = McFadden | first11 = L. A. | last12 = Mittlefehldt | first12 = D. W. | last13 = Nathues | first13 = A. | last14 = Palmer | first14 = E. | last15 = Reddy | first15 = V. | last16 = Raymond | first16 = C. A. | last17 = Russell | first17 = C. T. | title = Distinctive space weathering on Vesta from regolith mixing processes | journal = Nature | volume = 491 | issue = 7422 | pages = 79–82 | year = 2012 | pmid = 23128227|bibcode = 2012Natur.491...79P | s2cid = 4407636 }}); Titan
• Nitrogen ice ({{chem|N}}) – Pluto–Charon,{{cite web|title=Flowing nitrogen ice glaciers seen on surface of Pluto after New Horizons flyby|url=http://www.abc.net.au/news/2015-07-25/flowing-nitrogen-ice-glaciers-seen-on-surface-of-pluto/6647636|website=ABC|access-date=6 October 2015|date=25 July 2015}} Triton,{{cite encyclopedia|title = Encyclopedia of the Solar System|chapter = Triton|last1 = McKinnon|first1 = William B.|last2 = Kirk|first2 = Randolph L.|publisher = Elsevier|date = 2014|editor1-first = Tilman|editor1-last = Spohn|editor2-first = Doris|editor2-last = Breuer|editor3-first = Torrence|editor3-last = Johnson|edition = 3rd|location = Amsterdam; Boston|isbn = 978-0-12-416034-7|pages = 861–82|chapter-url = https://books.google.com/books?id=0bEMAwAAQBAJ&pg=PA861}} Kuiper belt objects, Plutinos
• Sulphur ({{chem|S}}) – Mercury; Earth; Mars; Jupiter moons – Io and Europa

• Salts – Earth, Mars, Ceres, Europa and Jupiter Trojans,{{cite journal|arxiv=1211.3099 |doi=10.1016/j.icarus.2012.11.025|title=Are large Trojan asteroids salty? An observational, theoretical, and experimental study|journal=Icarus|volume=223|issue=1|pages=359–366|year=2013|last1=Yang|first1=Bin|last2=Lucey|first2=Paul|last3=Glotch|first3=Timothy|bibcode=2013Icar..223..359Y|citeseerx=10.1.1.763.9669|s2cid=53323934}} Enceladus{{cite web|url=http://sciencing.com/salt-other-planets-23945.html |title=Salt on Other Planets |publisher=Sciencing |date=April 25, 2017 |author=Deziel, Chris }}
• Clays – Earth; Mars;[https://www.sciencedaily.com/releases/2012/12/121220144201.htm Clays On Mars: More Plentiful Than Expected]. Science Daily. December 20, 2012 asteroids including Ceres{{cite journal|url=http://irtfweb.ifa.hawaii.edu/~elv/icarus185.563.pdf |title=The surface composition of Ceres: Discovery of carbonates and iron-rich clays|journal=Icarus|volume=185|issue=2|pages=563–567|doi=10.1016/j.icarus.2006.08.022|year=2006|last1=Rivkin|first1=A.S|last2=Volquardsen|first2=E.L|last3=Clark|first3=B.E|bibcode=2006Icar..185..563R}} and Tempel 1;{{cite journal|last1=Napier|first1=W.M.|last2=Wickramasinghe|first2=J.T.|last3=Wickramasinghe|first3=N.C.|title=The origin of life in comets|journal=International Journal of Astrobiology|volume=6|issue=4|pages=321|year=2007|doi=10.1017/S1473550407003941|bibcode=2007IJAsB...6..321N|s2cid=121008660 }} Europa{{cite news |title=Clay-Like Minerals Found on Icy Crust of Europa |url=http://www.nasa.gov/jpl/news/europa-clay-like-minerals-20131211.html |agency=JPL, NASA.gov |date=December 11, 2013}}
• Sand – Earth, Mars, Titan
• Calcium carbonate ({{chem|Ca||C||O|3}}) – Earth, Mars{{cite journal

| last1=Boynton |first1=WV

| last2=Ming |first2=DW

| last3=Kounaves |first3=SP

| last4=Young |first4=SM

| last5=Arvidson |first5=RE

| last6=Hecht |first6=MH

| last7=Hoffman |first7=J

| last8=Niles |first8=PB

| last9=Hamara |first9=DK

| last10=Quinn

| first10=R. C.

| last11=Smith

| first11=P. H.

| last12=Sutter

| first12=B

| last13=Catling

| first13=D. C.

| last14=Morris

| first14=R. V.

| title=Evidence for Calcium Carbonate at the Mars Phoenix Landing Site

| url=http://planetary.chem.tufts.edu/Boynton%20etal%20Science%202009v325p61.pdf

| journal=Science |volume=325 |issue=5936 |pages= 61–64

| year=2009 |pmid=19574384 |bibcode=2009Sci...325...61B

| display-authors=3

| doi=10.1126/science.1172768

|s2cid=26740165

}}

{{cite journal

| display-authors=3

| year=2007

| title=Evidence for montmorillonite or its compositional equivalent in Columbia Hills, Mars

| journal=Journal of Geophysical Research

| volume=112 | issue=E6

|pages=E06S01

| doi=10.1029/2006JE002756

| bibcode = 2007JGRE..112.6S01C

| url=http://dspace.stir.ac.uk/bitstream/1893/17119/1/Clark2007_Evidence_for_montmorillonite_or_its_compositional_equivalent_in_Columbia_Hills_Mars.pdf

| last1=Clark

| first1=B. C

| last2=Arvidson

| first2=R. E

| last3=Gellert

| first3=R

| last4=Morris

| first4=R. V

| last5=Ming

| first5=D. W

| last6=Richter

| first6=L

| last7=Ruff

| first7=S. W

| last8=Michalski

| first8=J. R

| last9=Farrand

| first9=W. H

| last10=Yen

| first10=A

| last11=Herkenhoff

| first11=K. E

| last12=Li

| first12=R

| last13=Squyres

| first13=S. W

| last14=Schröder

| first14=C

| last15=Klingelhöfer

| first15=G

| last16=Bell

| first16=J. F

| hdl=1893/17119

| doi-access=free

}}

• Sodium carbonate ({{chem|Na|2|CO|3}}) – Earth, Ceres{{cite news |last1=Landau |first1=Elizabeth |last2=Greicius |first2=Tony |title=Recent Hydrothermal Activity May Explain Ceres' Brightest Area |url=http://www.nasa.gov/feature/jpl/recent-hydrothermal-activity-may-explain-ceres-brightest-area |date=29 June 2016 |work=NASA |access-date=30 June 2016 }}{{cite news |last=Lewin |first=Sarah |url=http://www.space.com/33302-ceres-bright-spots-new-composition.html |title=Mistaken Identity: Ceres Mysterious Bright Spots Aren't Epsom Salt After All |work=Space.com |date=29 June 2016 |access-date=2016-06-30 }}{{cite journal |title=Bright carbonate deposits as evidence of aqueous alteration on (1) Ceres |journal=Nature |date= 29 June 2016 |last=De Sanctis |first=M. C. |display-authors=etal|volume=536 |issue=7614 |doi=10.1038/nature18290 |pages=54–57 |pmid=27362221|bibcode = 2016Natur.536...54D |s2cid=4465999 }}

• Dry ice ({{chem|CO|2}}) – Mars (polar);{{cite journal |last1=Kounaves |first1=S. P. |display-authors=etal |year=2014 |title=Evidence of martian perchlorate, chlorate, and nitrate in Mars meteorite EETA79001: implications for oxidants and organics |journal=Icarus |volume=229 |page=169 |doi=10.1016/j.icarus.2013.11.012 |bibcode=2014Icar..229..206K}} Ariel;

{{cite journal| doi = 10.1016/j.icarus.2006.04.016| last1 = Grundy| first1 = W. M.| last2 = Young| first2 = L. A.| last3 = Spencer| first3 = J. R.| last4 = Johnson| first4 = R. E.| last5 = Young| first5 = E. F.| last6 = Buie| first6 = M. W.| date=October 2006 | title = Distributions of H₂O and CO₂ ices on Ariel, Umbriel, Titania, and Oberon from IRTF/SpeX observations| journal = Icarus| volume = 184| issue = 2| pages = 543–555| arxiv = 0704.1525| bibcode = 2006Icar..184..543G| s2cid = 12105236| ref = {{sfnRef|Grundy Young et al.|2006}}}}

Umbriel; Titania; Ganymede;{{cite journal|last1=Jones|first1=Brant M.|last2=Kaiser|first2=Ralf I.|last3=Strazzulla|first3=Giovanni|title=Carbonic acid as a reserve of carbon dioxide on icy moons: The formation of carbon dioxide (CO₂) in a polar environment|journal=The Astrophysical Journal|volume=788|issue=2|year=2014|page=170|doi=10.1088/0004-637X/788/2/170|bibcode=2014ApJ...788..170J|s2cid=51069998 |doi-access=free}} Callisto

• Carbon monoxide ice ({{chem|CO}}) - Triton{{cite journal|last1=Lellouch|first1=E.|last2=de Bergh|first2=C.|last3=Sicardy|first3=B.|last4=Ferron|first4=S.|last5=Käufl|first5=H.-U.|title=Detection of CO in Triton's atmosphere and the nature of surface-atmosphere interactions|journal=Astronomy and Astrophysics|volume=512|year=2010|pages=L8|doi=10.1051/0004-6361/201014339|bibcode=2010A&A...512L...8L|arxiv=1003.2866|s2cid=58889896}}

File:NH-Pluto-SputnikPlanum-HillaryMontes-NorgayMontes-20150714.jpg (photographed by New Horizons flyby on July 14, 2015) appears to exhibit geomorphological features previously thought to be unique to Earth.{{cite web |last=Gipson |first=Lillian |title=New Horizons Discovers Flowing Ices on Pluto |url=http://www.nasa.gov/feature/new-horizons-discovers-flowing-ices-on-pluto |date=24 July 2015 |work=NASA |access-date=24 July 2015 }}]]

Common rigid surface features include:

• Impact craters (though rarer on bodies with thick atmospheres, the largest being Hellas Planitia on Mars)
• Dunes as found on Venus, Earth, Mars and Titan
• volcanoes and cryovolcanoes
• Rilles
• Mountains (the highest being Rheasilvia on 4 Vesta){{Citation needed|date=July 2017}}
• Escarpments
• Canyons and valleys (the largest being Valles Marineris on Mars)
• Caves
• Lava tubes, found on Venus, Earth, The Moon and Mars

Normally, giant planets are considered to not have a surface, although they might have a solid core of rock or various types of ice, or a liquid core of metallic hydrogen. However, the core, if it exists, does not include enough of the planet's mass to be actually considered a surface. Some scientists consider the point at which the atmospheric pressure is equal to 1 bar, equivalent to the atmospheric pressure at Earth's surface, to be the surface of the planet,[http://www.universetoday.com/22719/surface-of-jupiter/] if the planet has no clear rigid terrain. Therefore the location of the surface of terrestrial planets do not depend on an atmospheric pressure of 1 Bar, even if for example Venus has a thick atmosphere with pressures at Venus's surface increasing well above Earth's atmospheric pressure.

{{Main|Planetary habitability|Biosignature|Lunar habitation}}

Planetary surfaces are investigated for the presence of past or present extraterrestrial life.{{Citation needed|date=October 2024}}

{{Gallery

|title=Some planetary surfaces of the Solar System and their compositions

|width=160 | height=170

|align=center

|footer=

|File:Mars Viking 21i093.png

|alt1=The dry, rocky and icy surface of planet Mars (photographed by Viking Lander 2, May 1979) is composed of iron-oxide rich regolith

|The dry, rocky and icy surface of planet Mars (photographed by Viking Lander 2, May 1979) is composed of iron-oxide rich regolith

|File:Huygens surface color.jpg

|alt3=Shiny silver coin with profile of Washington bust.

|Pebbled plains of Saturn's moon Titan (photographed by Huygens probe, January 14, 2005) composed of heavily compressed states of water ice. This is the only ground-based photograph of an outer Solar System planetary surface

|File:PIA02138.jpg

|alt4=Surface of comet Tempel 1 (photographed by the Deep Impact probe), consists of a fine powder of contains water and carbon dioxide rich clays, carbonates, sodium, and crystalline silicates.

|Surface of comet Tempel 1 (photographed by the Deep Impact probe), consists of a fine powder of contains water and carbon dioxide rich clays, carbonates, sodium, and crystalline silicates.

}}

• Extraterrestrial atmosphere
• Hydrosphere
• Subsurface ocean
• Ocean world
• Planetary radius
• Planetary geoid

{{reflist

| colwidth = 30em

| refs =

{{cite encyclopedia

| title = Encyclopedia of the Solar System

| chapter = Triton

| last1 = McKinnon

| first1 = William B.

| last2 = Kirk

| first2 = Randolph L.

| publisher = Academic Press

| date = 2007

| editor = Lucy Ann Adams McFadden

| editor2 = Lucy-Ann Adams

| editor3 = Paul Robert Weissman

| editor4 = Torrence V. Johnson

| edition = 2nd

| location = Amsterdam; Boston

| isbn = 978-0-12-088589-3

| pages = [https://archive.org/details/encyclopediaofso0000unse_u6d1/page/483 483–502]

| chapter-url = https://archive.org/details/encyclopediaofso0000unse_u6d1/page/483

}}

}}

Category:Planetary geology

Category:Surfaces