Many scientists believe tiny Martian microbes could flourish beneath the red planet's ice-cemented polar caps, or even in briny puddles of ultra-salty water—which they believe may be locked under Mars' soil in seasonal flows. But here's one important question about the possibility of life on Mars: What the heck does it eat?

According to Gary King, a biologist at Louisiana State University, the surprising answer could be a scentless, atmospheric gas: carbon monoxide. In a new study in the science journal PNAS, King has concluded that enough of the gas seeps into Mars's soil from the planet's atmosphere to feed hearty lifeforms. Such organisms which could look like Alkalilimnicola ehrlichii, a carbon monoxide-munching microbe found in California in 2007.

To read more, click here.