From Ethan Siegel at Forbes: The first test was performed first, and came back negative. The second test was next, and also came back negative. By time the third test was performed, with both landers in situ, the prospects were pretty grim, but the data was taken anyway. To the surprise of almost everyone, both Viking 1 and 2 detected metabolized, radioactive carbon-14 as part of the carbon dioxide emitted. They even took their samples from different locations: one from soil in direct sunlight, the other from soil found under a rock. In both samples, the carbon dioxide emission was immediate and sustained after the first injection. To great excitement and fanfare, the team led by Gilbert Levin thought they Read More ›