Using special infrared telescopes, NASA scientists have discovered the presence of regular methane “plumes” on Mars, further raising the possibility that life once existed – or currently exists – on Mars. Methane gas is one of the simplest organic molecules, a common byproduct of biological life. In fact, more than 90% of the Earth’s methane comes from biologic sources.
It is important to point out that the presence of methane is, in and of itself, not conclusive evidence of life. Methane can be produced from purely non-biological chemical reactions. Based on NASA’s current findings, it’s impossible to say if the gas is from biologic or geologic sources.
Interestingly, the article also highlights recent research showing that microbial life can live quite happily miles underground. A team from Indiana University recently discovered microbes living two miles beneath the Earth’s surface. These microbes harnessed energy from the radioactive decay of nearby rocks to generate fuel. If Martian life does actually exist, it would likely be deep underground, where the temperature is significantly warmer and liquid water would flow freely.
It will be interesting to see if the next Mars rover mission, scheduled for 2011, will target one of the suspicious methane-rich sites.