Islands of ice on Mars and Pluto

• Published in: Journal of Geophysical Research: Planets
• Main Authors: Sori, Michael M., Bapst, Jonathan, Becerra, Patricio, Byrne, Shane
• Other Authors: Univ Arizona, Lunar & Planetary Lab
• Format: Article in Journal/Newspaper
• Language: English
• Published: AMER GEOPHYSICAL UNION 2019
• Subjects: ice mounds; volatiles; craters; south polar layered deposits; Sputnik Planitia; Sputnik; Ice Sheet
• Online Access: http://hdl.handle.net/10150/636169; https://doi.org/10.1029/2018je005861

Ice sheets, such as the polar layered deposits (PLDs) of Mars, are of great interest as records of past climate. Smaller outlier ice deposits near the north and south PLDs are likely more sensitive to climate changes and thus may hold information about more recent climate history. However, the southern outlier deposits have largely remained unmapped and unanalyzed. Here, we identify 31 deposits near, but separated from, Mars's south PLDs, all of which are located within impact craters >15 km in diameter. On the basis of morphology, radar analysis, physical similarity to portions of the PLD margin, and overall similarity to previously described deposits in Mars's north polar region, we conclude that these deposits are primarily composed of water ice. An additional 66 craters contain smaller depositional features, some of which may be remnant ice deposits. The 31 outlier ice deposits represent a previously unquantified inventory of water on Mars, with a total volume between 15,000 and 38,000 km(3). In addition, we identify five analogous outlier nitrogen ice deposits located within impact craters near Sputnik Planitia, the large nitrogen ice sheet on Pluto. Although important differences exist between Mars and Pluto, broad physical similarities between the two cases suggest that the topography and microclimates of impact craters cause them to be favorable locations for volatile accumulation and/or retention throughout the Solar System. NASA's Mars Data Analysis Program National Aeronautics & Space Administration (NASA) [80NSSC17K0510] 6 month embargo; published online 15 Oct 2019 This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [e-mail].