Mercury’s EUV Reflectance Spectrum From Mariner 10 Revisited
Abstract
Carbon, as graphite, has emerged from recent analyses of MESSENGER spectrophotometry and theoretical modeling as a possible source for the darkening component in the Low Reflectance Material (LRM), pervasive across Mercury’s surface. Murchie et al. (Icarus 254, 287, 2015) propose graphite, in amounts consistent with results from MESSENGER’s elemental experiments for the presence of C, as the most likely darkening component in LRM. Vander Kaaden and McCubbin (JGR Planets 120, 195, 2015) report that graphite would be the only buoyant phase in an early magma ocean, and any primary flotation crust would have retained C in the form of graphite. Alternatively, Gillis-Davis et al. (Abstract P1 1A-07, AGU, 2013) suggest that nanophase and microphase iron, produced by impacts into Mercury’s crust before and during the late heavy bombardment, could darken the LRM. Carbon in the forms of graphite and anthracite has distinctive far-UV spectral reflectance features. The MESSENGER MASCS UVVS spectrometer does not extend to wavelengths short enough to observe these features. The Mariner 10 EUV airglow spectrometer observed broad swaths of Mercury in 10 filters at wavelengths ranging from 304Å to 1657Å, each having 20Å passbands. We now re-analyze these data in a search for this distinctive UV signature of graphite across large areas of Mercury’s surface, and will report on the results.
- Publication:
-
AAS/Division for Planetary Sciences Meeting Abstracts #47
- Pub Date:
- November 2015
- Bibcode:
- 2015DPS....4710704V