-
Tytuł:
-
New Illumination and Temperature Constraints of Mercury's Volatile Polar Deposits.
-
Autorzy:
-
Hamill CD; Johns Hopkins University Applied Physics Laboratory, Laurel, MD, USA.
Chabot NL; Johns Hopkins University Applied Physics Laboratory, Laurel, MD, USA.
Mazarico E; NASA Goddard Space Flight Center, Greenbelt, MD, USA.
Siegler MA; Planetary Science Institute, Tucson, AZ, USA.
Barker MK; NASA Goddard Space Flight Center, Greenbelt, MD, USA.
Martinez Camacho JM; Southern Methodist University, Dallas, TX, USA.
-
Źródło:
-
The planetary science journal [Planet Sci J] 2020 Dec; Vol. 1 (3), pp. 57. Date of Electronic Publication: 2020 Oct 26.
-
Typ publikacji:
-
Journal Article
-
Język:
-
English
-
Imprint Name(s):
-
Original Publication: [Bristol] : IOP Publishing
-
References:
-
Science. 2013 Jan 18;339(6117):300-3. (PMID: 23196905)
Science. 1992 Oct 23;258(5082):640-3. (PMID: 17748899)
Science. 2013 Jan 18;339(6117):296-300. (PMID: 23196910)
Nature. 2012 Jun 20;486(7403):378-81. (PMID: 22722197)
Science. 1992 Oct 23;258(5082):643-6. (PMID: 17748900)
Science. 1992 Oct 23;258(5082):635-40. (PMID: 17748898)
Geophys Res Lett. 2016 Sep 28;43(18):9461-9468. (PMID: 28943677)
J Geophys Res Planets. 2018 Feb;123(2):666-681. (PMID: 29552436)
Earth Planet Sci Lett. 2019 Aug 15;520:26-33. (PMID: 32454531)
Adv Space Res. 2018 Dec 1;62(11):3214-3228. (PMID: 30846890)
Appl Opt. 1985 Jan 15;24(2):296. (PMID: 18216944)
Icarus. 2016 Jun;280:158-171. (PMID: 29332948)
Science. 2013 Jan 18;339(6117):292-6. (PMID: 23196909)
-
Grant Information:
-
80NSSC19K0881 United States ImNASA Intramural NASA
-
Entry Date(s):
-
Date Created: 20201119 Latest Revision: 20240330
-
Update Code:
-
20240330
-
PubMed Central ID:
-
PMC7668200
-
DOI:
-
10.3847/psj/abb1c2
-
PMID:
-
33210087
-
Images from the Mercury Dual Imaging System (MDIS) aboard the MErcury Surface, Space ENvironment, GEochemistry, and Ranging mission reveal low-reflectance polar deposits that are interpreted to be lag deposits of organic-rich, volatile material. Interpretation of these highest-resolution images of Mercury's polar deposits has been limited by the available topography models, so local high-resolution (125 m pixel -1 ) digital elevation models (DEMs) were made using a combination of data from the Mercury Laser Altimeter (MLA) and from shape-from-shading techniques using MDIS images. Local DEMs were made for eight of Mercury's north polar craters; these DEMs were then used to create high-resolution simulated image, illumination, and thermal models. The simulated images reveal that the pixel brightness variations imaged within Mercury's low-reflectance deposits are consistent with scattered light reflecting off of topography and do not need to be explained by volatile compositional differences as previously suggested. The illumination and thermal models show that these low-reflectance polar deposits extend beyond the permanently shadowed region, more than 1.0 km in some locations, and correspond to a maximum surface temperature of greater than 250 K but less than 350 K. The low-reflectance boundaries of all eight polar deposits studied here show a close correspondence with the surface stability boundary of coronene (C 24 H 12 ). While coronene should only be viewed as a proxy for the myriad volatile compounds that may exist in Mercury's polar deposits, coronene's surface stability boundary supports the idea that Mercury's low-reflectance polar deposits are composed of macromolecular organic compounds, consistent with the hypotheses of exogenous transport and in situ production.