Mineralogical indicators of Mercury's hollows composition in MESSENGER color observations. Issue 4 (25th February 2016)

• Record Type: Journal Article
• Authors: Vilas, Faith; Domingue, Deborah L.; Helbert, Jörn; D'Amore, Mario; Maturilli, Alessandro; Klima, Rachel L.; Stockstill‐Cahill, Karen R.; Murchie, Scott L.; Izenberg, Noam R.; Blewett, David T.; Vaughan, William M.; Head, James W.
• Is Part Of: Geophysical research letters. Volume 43:Issue 4(2016)
• Page Start: 1450
• Page End: 1456
• Publication Date: 2016-02-25
• Subjects: Mercury (planet) -- MESSENGER -- hollows -- Mercury surface composition -- spectral reflectance; Geophysics -- Periodicals; Planets -- Periodicals; Lunar geology -- Periodicals; 550
• DOI: 10.1002/2015GL067515
• Languages: English
• ISSNs: 0094-8276

Abstract

Abstract: Early during MErcury Surface Space ENvironment GEochemistry, and Ranging (MESSENGER)'s orbital mission, the Mercury Dual‐Imaging System imaged the landform called hollows on the two craters Dominici and Hopper, using its Wide‐Angle Camera with eight narrowband color filters ranging from 433 to 996 nm. An absorption feature centered in the MDIS 629 nm filter is evident in reflectance spectra for Dominici's south wall/rim hollows. A different absorption feature found in photometry of Dominici's center hollows extends through the MDIS 828 nm filter. Hollows in Hopper exhibit a weaker spectral absorption feature than that observed in Dominici's center. At Dominici, we postulate that fresher hollows‐hosting material in the wall/rim was exposed to the space environment through a process of slumping of the overlying material. With time, local and global processes darken the hollows and change or mix the surface mineralogy, so that the spectral signature evolves. The hollows could contain low‐density MgS and an opaque component, potentially derived from background material. Key Points: First positive ID of absorption features suggesting mineralogy in MESSENGER surface reflectance photometry First ID of absorption features in Mercury's hollows Variation in absorption features potential key to alteration (space weathering) with age