By JON M. CHANG | ABC News
It's another strike for the probability of life on Mars.
Curiosity, NASA's rover on the red planet's surface, has failed to detect any significant amount of methane in Mars' atmosphere, contrary to what was observed by telescopes on Earth, according to a recent paper published in the journal Science.
Scientist use the presence of methane as a possible indicator of life.
Lyle Whyte, vice-chair of the Canadian Astrobiology Network, said that it was a bad day for the search for life on Mars. "It's not a definitive sign saying that there is no life on Mars, but it's not a good sign," he told ABC News. "We have a problem."
Whyte, who was not involved with the paper but collaborates with NASA on other projects, said that methane is like a smoking gun for microbial life. "Ninety percent of the methane of Earth's atmosphere originate from microbes," he said. "That's why people got excited about methane in Mars' atmosphere."
The main evidence for methane on Mars comes from Michael Mumma, a planetary scientist at NASA. One of his papers combined methane observations from the Keck Observatory and the Infrared Telescope Facility, both in Hawaii. "When we saw the methane plumes, we saw values range from 20 to 60 parts per billion," he said. "Curiosity's upper limit is only 1.4 parts per billion." ...more