• Curiosity rover has detected a bonanza of organic compounds on the surface of Mars and seasonal fluctuations of atmospheric methane.
  • But NASA scientists emphasized there could be non-biological explanations for both discoveries made by the Curiosity rover at a site called Gale crater, leaving the issue of Martian life a tantalizing but unanswered question.
  • Three different types of organic molecules were discovered when the rover dug just 5 cm into roughly 3.5 billion-year-old mudstone, a fine-grained sedimentary rock, at Gale crater, apparently the site of a large lake when ancient Mars was warmer and wetter than the desolate planet it is today.
  • Curiosity also measured an unexpectedly large seasonal cycle in the low levels of atmospheric methane.
  • About 95 % of the methane in Earth’s atmosphere is produced from biological activity, though the scientists said it is too soon to know if the Martian methane also is related to life.
  • Organic molecules are the building blocks of life, though they can also be produced by chemical reactions unrelated to life.
  • Whether anywhere other than Earth has harbored life, perhaps even in microbial form, is one of the paramount questions in science.
  • There’s three possible sources for the organic material.
  • The first one would be life, which we don’t know about.
  • The second would be meteorites. And the last one is geological processes, meaning the rock-forming processes themselves.
  • What the organic detections in the rock do is to add to the story of habitability.
  • It tells us that this ancient environment on Mars could have supported life.
  • Everything that was needed to support life was there. But it doesn’t tell us that life was there.
  • The amount of methane peaked at the end of summer in the northern hemisphere at about 2.7 times the level of the lowest seasonal amount.
  • The scientists were surprised to find organic compounds, especially in the amounts detected, considering the harsh conditions, including bombardment of solar radiation on the Martian surface.