The question of life on Mars could be answered, thanks to NASA’s Curiosity rover. The space agency’s latest science robot has been on the Red Planet for more than a year, but it has yet to detect traces of methane.
The lack of methane in Mars’ atmosphere was announced by NASA’s Jet Propulsion Laboratory on Thursday and comes as a surprise to scientists, since previous data reported by US and international scientists indicated positive detections.
Methane is the most abundant hydrocarbon in the solar system. Each molecule is made from one carbon atom and four hydrogen atoms. Precious reports of small amounts of methane were based on observations from Earth and orbit around Mars.
However, the JPL announced that in six samples taken by Curiosity between October 2012 and June 2013, the amount of methane in the current Martian atmosphere was just 1.3 parts per billion. The amount is one-sixth what some earlier estimates showed.
Many microbes on Earth release methane waste, which mixes with the atmosphere. Substantial contributions on our planet come from cows, pigs, and humans. The Guardian notes that not all microbes release methane.
NASA chemist Chris Webster explained that the question of life on Mars, at least methane-producing microbes, appears to be answered. However, Webster went on to say, “But there are other microbes that do not produce methane, so there remains a possibility that there is subsurface microbial activity that is not emitting the gas.”
Webster, who heads the team that ran the analysis at the JPL in California, added that it’s too soon to call off the search for current life on Mars. He explained, “The search for life on Mars is far from over. It takes two particular efforts. One is to look for current microbial activity. But the other is to analyze the rocks to look for signs that the conditions were once right for life. And we are doing that now.”
While NASA’s Curiosity rover looks for past signs of life on Mars, the European Space Agency which will send its own alien-hunting probe to Mars in 2018. The ExoMars will be equipped to look for existing life while Curiosity is meant to look for past life.