RT Journal Article SR Electronic T1 Question of Martian Methane Is Still Up in the Air JF Science JO Science FD American Association for the Advancement of Science SP 733 OP 733 DO 10.1126/science.338.6108.733 VO 338 IS 6108 A1 Kerr, Richard A. YR 2012 UL http://science.sciencemag.org/content/338/6108/733.abstract AB