The imprint of atmospheric evolution in the D/H of Hesperian clay minerals on Mars

MSL Science Team

Research output: Contribution to journalArticle

65 Citations (Scopus)


The deuterium-to-hydrogen (D/H) ratio in strongly bound water or hydroxyl groups in ancient martian clays retains the imprint of the water of formation of these minerals. Curiosity’s Sample Analysis at Mars (SAM) experiment measured thermally evolved water and hydrogen gas released between 550° and 950°C from samples of Hesperian-era Gale crater smectite to determine this isotope ratio. The D/H value is 3.0 (±0.2) times the ratio in standard mean ocean water. The D/H ratio in this ~3-billion-year-old mudstone, which is half that of the present martian atmosphere but substantially higher than that expected in very early Mars, indicates an extended history of hydrogen escape and desiccation of the planet.
Original languageEnglish
Pages (from-to)412-414
Number of pages3
Issue number6220
Early online date23 Jan 2015
Publication statusPublished - 23 Jan 2015


Cite this