Imaging Mercury's polar deposits during MESSENGER's low‐altitude campaign. Issue 18 (17th September 2016)

• Record Type: Journal Article
• Authors: Chabot, Nancy L.; Ernst, Carolyn M.; Paige, David A.; Nair, Hari; Denevi, Brett W.; Blewett, David T.; Murchie, Scott L.; Deutsch, Ariel N.; Head, James W.; Solomon, Sean C.
• Is Part Of: Geophysical research letters. Volume 43:Issue 18(2016)
• Page Start: 9461
• Page End: 9468
• Publication Date: 2016-09-17
• Subjects: Mercury -- polar -- ice -- MESSENGER; Geophysics -- Periodicals; Planets -- Periodicals; Lunar geology -- Periodicals; 550
• DOI: 10.1002/2016GL070403
• Languages: English
• ISSNs: 0094-8276

Abstract

Abstract: Images obtained during the low‐altitude campaign in the final year of the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) mission provide the highest‐spatial‐resolution views of Mercury's polar deposits. Images for distinct areas of permanent shadow within 35 north polar craters were successfully captured during the campaign. All of these regions of permanent shadow were found to have low‐reflectance surfaces with well‐defined boundaries. Additionally, brightness variations across the deposits correlate with variations in the biannual maximum surface temperature across the permanently shadowed regions, supporting the conclusion that multiple volatile organic compounds are contained in Mercury's polar deposits, in addition to water ice. A recent large impact event or ongoing bombardment by micrometeoroids could deliver water as well as many volatile organic compounds to Mercury. Either scenario is consistent with the distinctive reflectance properties and well‐defined boundaries of Mercury's polar deposits and the presence of volatiles in all available cold traps. Key Points: MESSENGER's low‐altitude images reveal Mercury's ice‐bearing polar deposits in high resolution All deposits imaged appear young, with low‐reflectance surfaces and well‐defined boundaries Brightness variations provide evidence for multiple volatile organic compounds in the deposits