Publication Date:
2015-03-07
Description:
We measured maps of atmospheric water (H2O) and its deuterated form (HDO) across the martian globe, showing strong isotopic anomalies and a significant high deuterium/hydrogen (D/H) enrichment indicative of great water loss. The maps sample the evolution of sublimation from the north polar cap, revealing that the released water has a representative D/H value enriched by a factor of about 7 relative to Earth's ocean [Vienna standard mean ocean water (VSMOW)]. Certain basins and orographic depressions show even higher enrichment, whereas high-altitude regions show much lower values (1 to 3 VSMOW). Our atmospheric maps indicate that water ice in the polar reservoirs is enriched in deuterium to at least 8 VSMOW, which would mean that early Mars (4.5 billion years ago) had a global equivalent water layer at least 137 meters deep.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Villanueva, G L -- Mumma, M J -- Novak, R E -- Kaufl, H U -- Hartogh, P -- Encrenaz, T -- Tokunaga, A -- Khayat, A -- Smith, M D -- New York, N.Y. -- Science. 2015 Apr 10;348(6231):218-21. doi: 10.1126/science.aaa3630. Epub 2015 Mar 5.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA. Catholic University of America, Washington, DC 20064, USA. geronimo.villanueva@nasa.gov. ; NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA. ; Iona College, New Rochelle, NY 10801, USA. ; European Southern Observatory, Munich, Germany. ; Max Planck Institute for Solar System Research, Katlenburg-Lindau 37191, Germany. ; Observatoire de Paris-Meudon, Meudon 92195, France. ; University of Hawaii-Manoa, Honolulu, HI 96822, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/25745065" target="_blank"〉PubMed〈/a〉
Keywords:
Atmosphere
;
Deuterium/analysis
;
Deuterium Oxide
;
Evolution, Planetary
;
Extraterrestrial Environment
;
Ice
;
*Mars
;
*Water
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
