skip to main content

DOE PAGESDOE PAGES

This content will become publicly available on October 6, 2018

Title: Meteorite constraints on Martian atmospheric loss and paleoclimate

The evolution of Mars' atmosphere to its currently thin state incapable of supporting liquid water remains poorly understood and has important implications for Martian climate history. Martian meteorites contain trapped atmospheric gases that can be used to constrain both the timing and effectiveness of atmospheric escape processes. Here in this article, measurements of xenon isotopes in two ancient Martian meteorites, ALH 84001 and NWA 7034, are reported. The data indicate an early episode of atmospheric escape that mass fractionated xenon isotopes culminated within a few hundred million years of planetary formation, and little change to the atmospheric xenon isotopic composition has occurred since this time. In contrast, on Earth atmospheric xenon fractionation continued for at least two billion years (Pujol et al., 2011). Such differences in atmospheric Xe fractionation between the two planets suggest that climate conditions on Mars may have differed significantly from those on Archean Earth. For example, the hydrogen escape flux may not have exceeded the threshold required for xenon escape on Mars after 4.2–4.3 Ga, which indicates that Mars may have been significantly drier than Earth after this time.
Authors:
 [1]
  1. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). Nuclear and Chemical Sciences Division
Publication Date:
Report Number(s):
LLNL-JRNL-711257
Journal ID: ISSN 0012-821X
Grant/Contract Number:
AC52-07NA27344; NNH14AX56I
Type:
Accepted Manuscript
Journal Name:
Earth and Planetary Science Letters
Additional Journal Information:
Journal Volume: 479; Journal Issue: C; Journal ID: ISSN 0012-821X
Publisher:
Elsevier
Research Org:
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Sponsoring Org:
USDOE; National Aeronautic and Space Administration (NASA)
Country of Publication:
United States
Language:
English
Subject:
58 GEOSCIENCES; 79 ASTRONOMY AND ASTROPHYSICS; Mars; xenon; atmospheric evolution; meteorite; mass spectrometry; noble gas
OSTI Identifier:
1430989