Background levels of methane in Mars’ atmosphere show strong seasonal variations

• DOI: 10.1126/science.aaq0131
• Publication Date: 2018-06-07T19:05:41Z
• Authors: Christopher R. We...; Paul R. Mahaffy; Sushil K. Atreya; John E. Moores; Gregory J. Flesch; Charles Malespin; Christopher P. McKay; German Martinez; Christina L. Smith; Javier Martin-Torres; Javier Gomez-Elvira; Maria-Paz Zorzano; Michael H. Wong; Melissa G. Trainer; Andrew Steele; Doug Archer; Brad Sutter; Patrice J. Coll; Caroline Freissinet; Pierre-Yves Meslin; Raina V. Gough; Christopher H. House; Alexander Pavlov; Jennifer L. Eigen...; Daniel P. Glavin; John C. Pearson; Didier Keymeulen; Lance E. Christensen; Susanne P. Schwenzer; Rafael Navarro-Go...; Jorge Pla-García; Scot C. R. Rafkin; Álvaro Vicente-Re...; Henrik Kahanpää; Daniel Viudez-Mor...; Michael D. Smith; Ari-Matti Harri; Maria Genzer; Donald M. Hassler; Mark Lemmon; Joy Crisp; Stanley P. Sander; Richard W. Zurek; Ashwin R. Vasavada
• Keywords: 550; 13. Climate action; 0103 physical sciences; [SDE.ES] Environmental Sciences/Environment and Society; [SDE.ES]Environmental Sciences/Environment and Society; [SDE.ES]Environmental Sciences/Environmental and Society; 01 natural sciences

Measuring martian organics and methane

The Curiosity rover has been sampling on Mars for the past 5 years (see the Perspective by ten Kate). Eigenbrode et al. used two instruments in the SAM (Sample Analysis at Mars) suite to catch traces of complex organics preserved in 3-billion-year-old sediments. Heating the sediments released an array of organics and volatiles reminiscent of organic-rich sedimentary rock found on Earth. Most methane on Earth is produced by biological sources, but numerous abiotic processes have been proposed to explain martian methane. Webster et al. report atmospheric measurements of methane covering 3 martian years and found that the background level varies with the local seasons. The seasonal variation provides an important clue for determining the origin of martian methane.

Science , this issue p. 1096 , p. 1093 ; see also p. 1068