Abstract
Quantitative measurements and photographic imaging of the moons of Mars set limits on several key geological conclusions-such as the orbits of the moons. Other examples include their estimated bulk densities where Phobos has a density of ∼1.876 g/cm3 and Deimos has a lower and less certain density of ∼1.48 g/cm3. Imaging data reveals a low albedo of both moons – Phobos: ∼0.07; Deimos: ∼0.08. Also, Phobos manifests distinct redder and bluer units, whereas the surface of Deimos is globally comparable to the Phobos redder units with localized streaks of brighter material. Further, the libration of Phobos suggests interior density distributions potentially ranging from a generally homogeneous interior to a slightly heterogeneous composition, whereas Deimos lacks sufficient evidence to estimate its interior density distribution. Both moons are mantled in a global equivalent of dozens to hundreds of meters of regolith deposits, yet they differ in their surface characteristics. Other than scattered boulders and an underabundance of fresh craters, the surface of Deimos is generally smooth with most observable impact craters filled with regolith. Conversely, thousands of boulders are observed on Phobos, and the moon is heavily modified by larger craters that are crosscut by grooves and mantled with regolith deposits and smaller generally fresh and unfilled craters. Yet models that focus on many key questions are inadequately supported by definitive evidence, or lack definitive evidence altogether – and these questions must be considered open. For example, how were Deimos and Phobos produced? Where are their geological histories similar, and where do they diverge? Why are the global densities of Deimos and Phobos different from each other, and why are these densities less than typical rocky bodies? What are their present-day geochemical compositions, density distributions, and deeper interior structures? What are the natures of the Phobos red and blue surface units? When did the Stickney Crater (\(D \sim 9\) km) impact take place on Phobos and how did the Stickney impact alter the surface and interior of Phobos? How and when were the Phobos grooves produced? Do large impact craters on Mars emplace observable deposits of martian ejecta on the martian moons? Finally, how might we collect definitive evidence to address these open questions?
Similar content being viewed by others
Data Availability
Not applicable (Review/Synthesis submission – no new research).
Code Availability
Not applicable (Review/Synthesis submission – no new research).
References
Y. Abe, Protoatmospheres and surface environment of protoplanets. Earth Moon Planets 108, 9–14 (2011). https://doi.org/10.1007/s11038-010-9368-x
S.N. Alexashkin, Yu.K. Zaiko, S.E. Sutugin, O.E. Kozlov, Phobos grunt soil sampling device. Sol. Syst. Res. 46, 555–561 (2012). https://doi.org/10.1134/S0038094612070052
J.C. Andrews-Hanna, M.T. Zuber, W.B. Banerdt, The Borealis basin and the origin of the martian crustal dichotomy. Nature 453, 1212–1216 (2008). https://doi.org/10.1038/nature07011
E. Asphaug, H.J. Melosh, The Stickney impact of Phobos: a dynamical model. Icarus 101, 144–164 (1993). https://doi.org/10.1006/icar.1993.1012
G.A. Avanesov, B.I. Bonev, F. Kempe, A.T. Bazilevsky, V. Boycheva, K.N. Chikov, M. Danz, D. Dimitrov, T. Duxbury, P. Gromatikov, D. Halmann, J. Head, V.N. Helfets, V. Kolev, V.I. Kostenko, V.A. Kottsov, V.M. Krasavtsev, V.A. Krasilov, A. Krumov, A.A. Kuzmin, K.D. Losev, K. Lumme, D.N. Mishev, D. Möhlmann, K. Muinonen, V.M. Murav’ev, S. Murchie, B. Murray, W. Neumann, L. Paul, D. Petkov, I. Petuchova, W. Pössel, B. Rebel, Yu.G. Shkuratov, S. Simeonov, B. Smith, A. Totev, Yu. Uzunov, V.P. Fedotov, G.-G. Weide, H. Zapfe, B.S. Zhukov, Ya.L. Ziman, Television observations of Phobos. Nature 341, 585–587 (1989). https://doi.org/10.1038/341585a0
G. Avanesov, B. Zhukov, Ya. Ziman, V. Kostenko, A. Kuzmin, V. Murav’ev, V. Fedotov, B. Bonev, D. Mishev, D. Petkov, A. Krumov, S. Simeonov, V. Boycheva, Yu. Uzunov, G.-G. Weide, D. Halmann, W. Pössel, J. Head, S. Murchie, Yu.G. Schkuratov, R. Berghänel, M. Danz, T. Mangoldt, U. Pihan, U. Weidlich, K. Lumme, K. Muinonen, J. Peltoniemi, T. Duxbury, B. Murray, K. Herkenhoff, F. Fanale, W. Irvine, B. Smith, Results of TV imaging of Phobos (experiment VSK-FREGAT). Planet. Space Sci. 39, 281–295 (1991). https://doi.org/10.1016/0032-0633(91)90150-9
A. Bagheri, A. Khan, M. Efroimsky, M. Kruglyakov, D. Giardini, Dynamical evidence for Phobos and Deimos as remnants of a disrupted common progenitor. Nat. Astron. 5, 539–543 (2021)
A.T. Basilevsky, T.V. Shingareva, The selection and characterization of the Phobos-Soil landing sites. Sol. Syst. Res. 44, 38–43 (2010). https://doi.org/10.1134/S0038094610010053
A.T. Basilevsky, C.A. Lorenz, T.V. Shingareva, J.W. Head, K.R. Ramsley, A.E. Zubarev, The surface geology and geomorphology of Phobos. Planet. Space Sci. 102, 95–118 (2014). https://doi.org/10.1016/j.pss.2014.04.013
A.T. Basilevsky, J.W. Head, F. Horz, K. Ramsley, Survival times of meter-sized rock boulders on the surface of airless bodies. Planet. Space Sci. 117, 312–328 (2015). https://doi.org/10.1016/j.pss.2015.07.003
J.A. Burns, Contradictory clues as to the origin of the Martian moons, in Mars, ed. by H.H. Kieffer, B.M. Jakosky, C.W. Snyder, M.S. Matthews. (Univ. of Ariz. Press, Tucson, 1992), pp. 1283–1301
R. Canup, J. Salmon, Origin of Phobos and Deimos by the impact of a Vesta-to-Ceres sized body with Mars. Sci. Adv. 4, 1–6 (2018). https://doi.org/10.1126/sciadv.aar6887
B. Carry, Density of asteroids. Planet. Space Sci. 73, 98–118 (2012). https://doi.org/10.1016/j.pss.2012.03.009
A. Cazenave, A. Dobrovolskis, B. Lago, Orbital history of the Martian satellites with inferences on their origin. Icarus 44, 730–744 (1980). https://doi.org/10.1016/0019-1035(80)90140-2
C.R. Chapman, Space weathering of asteroid surfaces. Annu. Rev. Earth Planet. Sci. 32, 539–567 (2004). https://doi.org/10.1146/annurev.earth.32.101802.120453
L. Chappaz, H.J. Melosh, M. Vaquero, K.C. Howell, Transfer of impact ejecta material from the surface of Mars to Phobos and Deimos. Astrobiology 13, 963–980 (2013). https://doi.org/10.1089/ast.2012.0942
V. Ciarletti, A variety of radars designed to explore the hidden structures and properties of the Solar System’s planets and bodies. C. R. Phys. 17, 966–975 (2016). https://doi.org/10.1016/j.crhy.2016.07.022
F. Cipriani, O. Witasse, F. Leblanc, R. Modolo, R.E. Johnson, A model of interaction of Phobos’ surface with the martian environment. Icarus 212, 643–648 (2011). https://doi.org/10.1016/j.icarus.2011.01.036
R.I. Citron, H. Genda, S. Ida, Formation of Phobos and Deimos via a giant impact. Icarus 252, 334–338 (2015). https://doi.org/10.1016/j.icarus.2015.02.011
R.A. Craddock, The origin of Phobos and Deimos, in Proceedings of the Lunar Planet Sci. Conf. XXV. Abstract, vol. 293 (1994)
R.A. Craddock, Are Phobos and Deimos the result of a giant impact? Icarus 211, 1150–1161 (2011). https://doi.org/10.1016/j.icarus.2010.10.023
A.N. Deutsch, J.W. Head, K.R. Ramsley, C.M. Pieters, R.W.K. Potter, A.M. Palumbo, M.S. Bramble, J.P. Cassanelli, E.R. Jawin, L.M. Jozwiak, H.H. Kaplan, C.F. Lynch, A.C. Pascuzzo, L. Qiao, D.K. Weiss, Science exploration architecture for Phobos and Deimos: the role of Phobos and Deimos in the future exploration of Mars. Adv. Space Res. 62, 2174–2186 (2018). https://doi.org/10.1016/j.asr.2017.12.017
A.R. Dobrovolskis, J.A. Burns, Life near the Roche limit: behavior of ejecta from satellites close to planets. Icarus 42, 422–441 (1980). https://doi.org/10.1016/0019-1035(80)90105-0
T.C. Duxbury, The figure of Phobos. Icarus 78, 169–180 (1989). https://doi.org/10.1016/0019-1035(89)90075-4
T.C. Duxbury, J. Veverka, Viking imaging of Phobos and Deimos: an overview of the primary mission. J. Geophys. Res. 82, 4203–4211 (1977). https://doi.org/10.1029/JS082i028p04203
T.C. Duxbury, J. Veverka, Deimos encounter by viking: preliminary imaging results. Science 201, 812–814 (1978). https://doi.org/10.1126/science.201.4358.812
T. Duxbury, M.S. Robinson, C. van der Bogert, P. Thomas, G. Neukum, H. Hiesinger, Phobos grooves, a lunar analog, in Proceedings of the 38th COSPAR Scientific Assembly, Abstract B04-0037-10 (2010)
F.P. Fanale, J.R. Salvail, Loss of water from Phobos. Geophys. Res. Lett. 16, 287–290 (1989). https://doi.org/10.1029/GL016i004p00287
A. Fujiwara, N. Asada, Impact fracture patterns on Phobos ellipsoids. Icarus 56, 590–602 (1983). https://doi.org/10.1016/0019-1035(83)90176-8
M.J. Gaffey, Space weathering and the interpretation of asteroid reflectance spectra. Icarus 209, 564–574 (2010). https://doi.org/10.1016/j.icarus.2010.05.006
M.L. Gernhardt, S.P. Chappell, O.S. Bekdash, F.J. Abercromby, E.Z. Crues, Z.Q. Li, P. Bielski, A.S. Howe, Human and Robotic Exploration Missions to Phobos Prior to Crewed Mars Surface Missions (IEEE Press, New York, 2016). ISBN: 978-1-4673-7676-1/16. https://ntrs.nasa.gov/citations/20170009183
M. Hamelin, Motion of blocks on the surface of Phobos: new constraints for the formation of grooves. Planet. Space Sci. 59, 1293–1307 (2011). https://doi.org/10.1016/j.pss.2010.05.023
D.P. Hamilton, A.V. Krivov, Circumplanetary dust dynamics: effects of solar gravity, radiation pressure, planetary oblateness, and electromagnetism. Icarus 123, 503–523 (1996). https://doi.org/10.1006/icar.1996.0175
J.W. Head, The geology of Phobos and Deimos and the origin of grooves on Phobos: scientific questions for the Phobos mission, in Scientific and Methodological Aspects of the Phobos Study (USSR, Moscow, 1986), pp. 61–69
J.W. Head, M.J. Cintala, Grooves on Phobos: Evidence for Possible Secondary Cratering Origin. Reports of the Planetary Geology Program 1978–1979, NASA TM-80339, pp. 19–21 (1979)
J.W. Head, L. Wilson, Dynamics of groove formation on Phobos by ejecta from Stickney crater: predictions and tests, in Proceedings of the First Moscow Solar System Symposium (1M-S3). Abstract, vol. 32 (2010)
A.J. Hesselbrock, D.A. Minton, An ongoing satellite–ring cycle of Mars and the origins of Phobos and Deimos. Nat. Geosci. 10, 266–269 (2017). https://doi.org/10.1038/ngeo2916
K.C. Horstman, H.J. Melosh, Drainage pits in cohesionless materials: implications for the surface of Phobos. J. Geophys. Res. 94, 12433–12441 (1989). https://doi.org/10.1029/JB094iB09p12433
D.M. Hunten, Capture of Phobos and Deimos by protoatmospheric drag. Icarus 37, 113–123 (1979). https://doi.org/10.1016/0019-1035(79)90119-2
T.A. Hurford, E. Asphaug, J.N. Spitale, D. Hemingway, A.R. Rhoden, W.G. Henning, B.G. Bills, S.A. Kattenhorn, M. Walker, Tidal disruption of Phobos as the cause of surface fractures. J. Geophys. Res., Planets 121, 1054–1065 (2016). https://doi.org/10.1002/2015JE004943
R. Hyodo, H. Genda, S. Charnoz, P. Rosenblatt, On the impact origin of Phobos and Deimos. I. Thermodynamic and physical aspects. Astrophys. J. 845, 125–133 (2017). https://doi.org/10.3847/1538-4357/aa81c4
E. Illes, A. Horváth, On the origin of grooves on Phobos, in Proceedings of the Symposium on Progress in Planetary Exploration, Budapest (1980)
R.A. Jacobson, The orbits and masses of the Martian satellites and the libration of Phobos. Astron. J. 139, 668–679 (2010). https://doi.org/10.1088/0004-6256/139/2/668
A. Juhász, M. Tátrallyay, G. Gévai, M. Horányi, On the density of the dust halo around Mars. J. Geophys. Res. 98, 1205–1211 (1993). https://doi.org/10.1029/92JE02681
A.V. Krivov, L.L. Sokolov, V.V. Dikarev, Dynamics of Mars-orbiting dust: effects of light pressure and planetary oblateness. Celest. Mech. Dyn. Astron. 63, 313–339 (1995). https://doi.org/10.1007/BF00692293
K. Lambeck, On the orbital evolution of the Martian satellites. J. Geophys. Res. 84, 5651–5658 (1979). https://doi.org/10.1029/JB084iB10p05651
D.J. Lawrence, P.N. Peplowski, A.W. Beck, M.T. Burks, N.L. Chabot, M.J. Cully, R.C. Elphic, C.M. Ernst, S. Fix, J.O. Goldsten, E.M. Hoffer, H. Kusano, S.L. Murchie, B.C. Schratz, T. Usui, Z.W. Yokley, Measuring the elemental composition of Phobos: the Mars-Moon Exploration with GAmma rays and NEutrons (MEGANE) investigation for the Martian Moons eXploration (MMX) mission. Earth Space Sci. 6, 2605–2623 (2019). https://doi.org/10.1029/2019EA000811
S. Le Maistre, P. Rosenblatt, N. Rambaux, J.C. Castillo-Rogez, V. Dehant, J-C. Marty, Phobos interior from librations determination using Doppler and star tracker measurements. Planet. Space Sci. 85, 106–122 (2013). https://doi.org/10.1016/j.pss.2013.06.015
S. Le Maistre, A. Rivoldini, P. Rosenblatt, Signature of Phobos’ interior structure in its gravity field and libration. Icarus 321, 272–290 (2019). https://doi.org/10.1016/j.icarus.2018.11.022
M.M. Marinova, O. Aharonson, E. Asphaug, Mega-impact formation of the Mars hemispheric dichotomy. Nature 453, 1216–1219 (2008). https://doi.org/10.1038/nature07070
H.J. Melosh, Impact Cratering: A Geologic Process (Oxford University Press, New York, 1989)
C.M. Mercer, K.E. Young, J.R. Weirich, K.V. Hodges, B.L. Jolliff, J-A. Wartho, M.C. van Soest, Refining lunar impact chronology through high spatial resolution 40Ar/39Ar dating of impact melts. Sci. Adv. 1, 1–8 (2015). https://doi.org/10.1126/sciadv.1400050
G.G. Michael, G. Neukum, Planetary surface dating from crater size-frequency distribution measurements: partial resurfacing events and statistical age uncertainty. Earth Planet. Sci. Lett. 294, 223–229 (2010). https://doi.org/10.1016/j.epsl.2009.12.041
S. Murchie, S. Erard, Spectral properties and heterogeneity of Phobos from measurements by Phobos2. Icarus 123, 63–86 (1996). https://doi.org/10.1006/icar.1996.0142
S.L. Murchie, J.W. Head, N.D. Efford, Morphologic classes of grooves on Phobos, in Proceedings of the Lunar Planet Sci. Conf. 20 (1989), pp. 744–745
S.L. Murchie, D.T. Britt, J.W. Head, S.F. Pratt, P.C. Fisher, B.S. Zhukov, A.A. Kuzmin, L.V. Ksanfomality, A.V. Zharkov, G.E. Nikitin, F.P. Fanale, D.L. Blaney, J.F. Bell, M.S. Robinson, Color heterogeneity of the surface of Phobos: relationships to geologic features and comparison to meteorite analogs. J. Geophys. Res. 96, 5925–5945 (1991). https://doi.org/10.1029/90JB02354
S.L. Murchie, A.A. Fraeman, R.E. Arvidson, A.S. Rivkin, R.V. Morris, Internal characteristics of Phobos and Deimos from spectral properties and density: relationship to land-forms and comparison with asteroids, in Proceedings of the Lunar Planet Sci. Conf. 44 Abstract, vol. 1604 (2013)
S.L. Murchie, D.T. Britt, C.M. Pieters, The value of Phobos sample return. Planet. Space Sci. 102, 176–182 (2014). https://doi.org/10.1016/j.pss.2014.04.014
S.L. Murchie, P.C. Thomas, A.S. Rivkin, N.L. Chabot, in Asteroids IV: Phobos and Deimos, ed. by P. Michel, F.E. DeMeo, W.F. Bottke (Univ. of Arizona, Tucson, 2015), pp. 451–467. https://doi.org/10.2458/azu_uapress_9780816532131-ch024
J.B. Murray, New survey of the grooves of Phobos from Mars express images, in Proceedings of the First Moscow Solar System Symposium (1M-S3). Abstract, vol. 35 (2010)
J.B. Murray, Formation of the grooves of Phobos in the light of new evidence from Mars Express images, in EPSC-DPS Joint Meeting, vol. 6 (2011). Abstract EPSC-DPS2011-1003
J.B. Murray, D.C. Heggie, Character and origin of Phobos’ grooves. Planet. Space Sci. 102, 119–143 (2014). https://doi.org/10.1016/j.pss.2014.03.001
J.B. Murray, J.C. Iliffe, Martian impacts and the grooves of Phobos: implications for the evolution of Phobos’ rotation axis, in Proceedings of the Lunar Planet Sci. Conf. XXVI (1995), pp. 1015–1016
J.B. Murray, J.C. Iliffe, Morphological and geographical evidence for the origin of Phobos’ grooves from HRSC Mars Express images, in Martian Geomorphology, ed. by B.M.R. Balme, A.S. Bargery, C.J. Gallagher, S. Gupta (Geological Society London Special Publications, London, 2011), pp. 21–41
J.B. Murray, D.A. Rothery, G. Thornhill, J.-P. Muller, T. Cook, T. Day, J.C. Iliffe, The origin of grooves and crater chains of Phobos, in Proceedings of the Lunar Planet Sci. Conf. XXIII (1992), pp. 949–950
J.B. Murray, D.A. Rothery, G.D. Thornhill, J.-P. Muller, J.C. Iliffe, T. Day, A.C. Cook, The origin of Phobos grooves and crater chains. Planet. Space Sci. 42, 519–526 (1994). https://doi.org/10.1016/0032-0633(94)90093-0
J.B. Murray, J.C. Iliffe, J.-P. Muller, G. Neukum, S. Werner, M. Balme, the HRSC Co-Investigator Team, New evidence on the origin of Phobos’ parallel grooves from HRSC Mars Express, in Proceedings of the Planet Sci. Conf. XXXVII. Abstract, vol. 2195 (2006)
NASA Manned Spacecraft Center, Apollo 14 Preliminary Science Report, National Aeronautics and Space Administration, Washington, DC, NASA SP-272 (1971)
NASA Manned Spacecraft Center, Apollo 15 Preliminary Science Report, National Aeronautics and Space Administration, Washington, DC, NASA SP-289 (1972a)
NASA Manned Spacecraft Center, Apollo 16 Preliminary Science Report, National Aeronautics and Space Administration, Washington, DC, NASA SP-315 (1972b)
NASA Manned Spacecraft Center, Apollo 17 Preliminary Science Report, National Aeronautics and Space Administration, Washington, DC, NASA SP-330 (1973)
M. Nayak, F. Nimmo, B. Udrea, Effects of mass transfer between Martian satellites on surface geology. Icarus 267, 220–231 (2016). https://doi.org/10.1016/j.icarus.2015.12.026
Q. Nénon, A.R. Poppe, Ion weathering of the surface of the martian moon Phobos as inferred from Maven ion observations, in Proceedings of the Planet Sci. Conf. 51. Abstract, vol. 1214 (2020)
D.R. Ostrowski, C.H.S. Lacy, K.M. Gietzen, D.W.G. Sear, IRTF spectra for 17 asteroids from the C and X complexes: a discussion of continuum slopes and their relationships to C chondrites and phyllosilicates. Icarus 212, 682–696 (2011). https://doi.org/10.1016/j.icarus.2011.01.032
M. Pätzold, T. Andert, R. Jacobson, P. Rosenblatt, V. Dehant, Phobos: observed bulk properties. Planet. Space Sci. 102, 86–94 (2014b). https://doi.org/10.1016/j.pss.2014.01.004
M. Pätzold, T.P. Andert, G.L. Tyler, S.W. Asmar, B. Häusler, S. Tellmann, Phobos mass determination from the very close flyby of Mars Express in 2010. Icarus 229, 92–98 (2014a). https://doi.org/10.1016/j.icarus.2013.10.021
C.M. Pieters, S.K. Noble, Space weathering on airless bodies. J. Geophys. Res., Planets 121, 1865–1884 (2016). https://doi.org/10.1002/2016JE005128
C.M. Pieters, S. Murchie, N. Thomas, D. Britt, Composition of surface materials on the Moons of Mars. Planet. Space Sci. 102, 144–151 (2014). https://doi.org/10.1016/j.pss.2014.02.008
J. Pollack, J.A. Burns, An origin by capture of the Martian satellites? Bull. Am. Astron. Soc. 9, 518–519 (1977)
N. Rambaux, J.C. Castillo-Rogez, S. Le Maistre, P. Rosenblatt, Rotational motion of Phobos. Astron. Astrophys. 548(A14), 1–14 (2012). https://doi.org/10.1051/0004-6361/201219710
K.R. Ramsley, J.W. Head III., The origin of Phobos grooves from ejecta launched from impact craters on Mars: tests of the hypothesis. Planet. Space Sci. 75, 69–95 (2013a). https://doi.org/10.1016/j.pss.2012.10.007
K.R. Ramsley, J.W. Head III., Mars impact ejecta in the regolith of Phobos: bulk concentration and distribution. Planet. Space Sci. 87, 115–129 (2013b). https://doi.org/10.1016/j.pss.2013.09.005
K.R. Ramsley, J.W. Head, The Stickney Crater ejecta secondary impact crater spike on Phobos: implications for the age of Stickney and the surface of Phobos. Planet. Space Sci. 138, 7–24 (2017). https://doi.org/10.1016/j.pss.2017.02.004
K.R. Ramsley, J.W. Head, Origin of Phobos grooves: testing the Stickney Crater ejecta model. Planet. Space Sci. 165, 137–147 (2019). https://doi.org/10.1016/j.pss.2018.11.004
P. Rosenblatt, The origin of the Martian moons revisited. Astron. Astrophys. Rev. 19(44), 1–26 (2011). https://doi.org/10.1007/s00159-011-0044-6
P. Rosenblatt, S. Charnoz, On the formation of the martian moons from a circum-martian accretion disk. Icarus 221, 806–815 (2012). https://doi.org/10.1016/j.icarus.2012.09.009
P. Rosenblatt, A. Rivoldini, V. Dehant, Inhomegeneous mass distribution inside Phobos, in European Planetary Science Congress Abstracts, vol. 5 (2010). EPSC2010-235
P. Rosenblatt, S. Charnoz, K.M. Dunseath, M. Terao-Dunseath, A. Trinh, R. Hyodo, H. Genda, S. Toupin, Accretion of Phobos and Deimos in an extended debris disc stirred by transient moons. Nat. Geosci. 9, 581–585 (2016). https://doi.org/10.1038/NGEO2742
D.P. Rubincam, B.F. Chao, P.C. Thomas, The gravitational field of Deimos. Icarus 114, 63–67 (1995). https://doi.org/10.1006/icar.1995.1043
A.E. Saal, E.H. Hauri, M.L. Cascio, J.A. Van Orman, M.C. Rutherford, R.F. Cooper, Volatile content of lunar volcanic glasses and the presence of water in the Moon’s interior. Nature 454, 192–196 (2008). https://doi.org/10.1038/nature07047
V.S. Safronov, A.V. Vitjazev, The origin and early evolution of the terrestrial planets, in Chemistry and Physics of Terrestrial Planets, ed. by B.S.K. Saxena (Springer, New York, 1986), pp. 1–29
D.J. Scheeres, S. Van wal, Z. Olikara, N. Baresi, Dynamics in the Phobos environment. Adv. Space Res. 63, 476–496 (2019). https://doi.org/10.1016/j.asr.2018.10.016
N. Schmedemann, G.G. Michael, B.A. Ivanov, J.B. Murray, G. Neukum, The age of Phobos and its largest crater, Stickney. Planet. Space Sci. 102, 152–163 (2014). https://doi.org/10.1016/j.pss.2014.04.009
H.H. Schmitt, N.E. Petro, R.A. Well, M.S. Robinson, B.P. Weiss, C.M. Mercer, Revisiting the field geology of Taurus–Littrow. Icarus 298, 2–33 (2017). https://doi.org/10.1016/j.icarus.2016.11.042
X. Shi, K. Willner, J. Oberst, J. Ping, Y.E. ShuHua, Working models for the gravity field of Phobos. Sci. China, Phys. Mech. Astron. 55, 358–364 (2012). https://doi.org/10.1007/s11433-011-4606-4
X. Shi, K. Willner, J. Oberst, Evolution of Phobos’ orbit, tidal forces, dynamical topography, and related surface modification processes, in Proceedings of the Planet Sci. Conf. 44, Abstract, vol. 1889 (2013)
T.V. Shingareva, R.O. Kuzmin, Mass-wasting processes on the surface of Phobos. Sol. Syst. Res. 35, 431–443 (2001). https://doi.org/10.1023/A:1013082711274
S. Soter, A. Harris, Are striations on Phobos evidence of tidal stress? Nature 268, 421–422 (1977). https://doi.org/10.1038/268421a0
P. Stooke, Phobos and Deimos, in The International Atlas of Mars Exploration: Volume 1, 1953 to 2003: The First Five Decades (Cambridge University Press, New York, 2012), pp. 325–343. https://doi.org/10.1017/CBO9781139028301
G.A. Swann, N.G. Bailey, R.M. Batson, R.E. Eggleton, M.H. Hait, H.E. Holt, K.B. Larson, V.S. Reed, G.G. Schaber, R.L. Sutton, N.J. Trask, G.E. Ulrich, H.G. Wilshire, Geology of the Apollo 14 Landing Site in the Fra Mauro Highlands. United States Geological Survey Professional Paper 880 (1977)
M.B. Syal, J. Rovny, J.M. Owen, P.L. Miller, Excavating Stickney crater at Phobos. Geophys. Res. Lett. 43, 10595–10601 (2016). https://doi.org/10.1002/2016GL070749
A.M.K. Szeto, Orbital evolution and origin of the Martian satellites. Icarus 55, 133–168 (1983). https://doi.org/10.1016/0019-1035(83)90056-8
P. Thomas, Surface features of Phobos and Deimos. Icarus 40, 223–243 (1979). https://doi.org/10.1016/0019-1035(79)90069-1
P.C. Thomas, The shapes of small satellites. Icarus 77, 248–274 (1989). https://doi.org/10.1016/0019-1035(89)90089-4
P.C. Thomas, Ejecta emplacement on the Martian satellites. Icarus 131, 78–106 (1998). https://doi.org/10.1006/icar.1997.5858
P. Thomas, J. Veverka, A. Bloom, T. Duxbury, Grooves on Phobos: their distribution, morphology, and possible origin. J. Geophys. Res. 84, 8457–8477 (1979). https://doi.org/10.1029/JB084iB14p08457
P.C. Thomas, J. Veverka, R. Sullivan, D.P. Simonelli, M.C. Malin, M. Caplinger, W.K. Hartmann, P.B. James, Phobos: regolith and ejecta blocks investigated with Mars Orbiter Camera images. J. Geophys. Res. 105, 15091–15106 (2000). https://doi.org/10.1029/1999JE001204
N. Thomas, R. Stelter, A. Ivanov, N.T. Bridges, K.E. Herkenhoff, A.S. McEwen, Spectral heterogeneity on Phobos and Deimos: HiRISE observations and comparisons to Mars Pathfinder results. Planet. Space Sci. 59, 1281–1292 (2011). https://doi.org/10.1016/j.pss.2010.04.018
T. Usui, K. Bajo, W. Fijiya, Y. Furukawa, M. Koike, Y.N. Miura, H. Sugahara, S. Tachibana, Y. Takano, K. Kuramoto, The importance of Phobos sample return for understanding the Mars-Moon system. Space Sci. Rev. 216(49), 1–18 (2020). https://doi.org/10.1007/s11214-020-00668-9
J. Veverka, T.C. Duxbury, Viking observations of Phobos and Deimos: preliminary results. J. Geophys. Res. 82, 4213–4223 (1977). https://doi.org/10.1029/JS082i028p04213
P. Wiegert, M.A. Galiazzo, Meteorites from Phobos and Deimos at Earth? Planet. Space Sci. 142, 48–52 (2017). https://doi.org/10.1016/j.pss.2017.05.001
L. Wilson, J.W. Head, Dynamics of groove formation on Phobos by ejecta from Stickney, in Proceedings of the Lunar Planet Sci. Conf. XX (1989), pp. 1211–1212
L. Wilson, J.W. Head, Dynamics of groove formation on Phobos by ejecta from Stickney Crater: predictions and tests, in Proceedings of the Lunar Planet Sci. Conf. XXXVI. Abstract, vol. 1186 (2005)
L. Wilson, J.W. Head, Groove formation on Phobos: testing the Stickney ejecta emplacement model for a subset of the groove population. Planet. Space Sci. 105, 26–42 (2015). https://doi.org/10.1016/j.pss.2014.11.001
O. Witasse, T. Duxbury, A. Chicarro, N. Altobelli, T. Andert, A. Aronica, S. Barabash, J.-L. Bertaux, J.-P. Bibring, A. Cardesin-Moinelo, A. Cichetti, V. Companys, V. Dehant, M. Denis, V. Formisano, Y. Futaana, M. Giuranna, B. Gondet, D. Heather, H. Hoffmann, M. Holmström, N. Manaud, P. Martin, K.-D. Matz, F. Montmessin, T. Morley, M. Mueller, G. Neukum, J. Oberst, R. Orosei, M. Pätzold, G. Picardi, R. Pischel, J.J. Plaut, A. Reberac, P. PardoVoss, T. Roatsch, P. Rosenblatt, S. Remus, N. Schmedemann, K. Willner, T. Zegers, Mars express investigations of Phobos and Deimos. Planet. Space Sci. 102, 18–34 (2014). https://doi.org/10.1016/j.pss.2013.08.002
Acknowledgements
The authors greatly appreciate the insightful feedback and recommendations of the reviewers of this report. We found their detailed comments and suggestions to be very helpful in strengthening and clarifying the presentation and discussion of the final revised manuscript, and we thank them for their time and effort.
Funding
Not applicable.
Author information
Authors and Affiliations
Contributions
Both co-authors contributed substantially to the development and writing this report.
Corresponding author
Ethics declarations
Conflicts of interest/Competing interests
Not applicable.
Additional information
Publisher’s Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Rights and permissions
About this article
Cite this article
Ramsley, K.R., Head, J.W. The Origins and Geological Histories of Deimos and Phobos: Hypotheses and Open Questions. Space Sci Rev 217, 86 (2021). https://doi.org/10.1007/s11214-021-00864-1
Received:
Accepted:
Published:
DOI: https://doi.org/10.1007/s11214-021-00864-1