Martian Mystery: How Water Could Have Flowed on Chilly Mars

Nov 27, 2013

A University of Washington researcher may have helped solve a Martian mystery by explaining how the chilly surface of Mars could have once flowed with water.

Pictures of Mars clearly show features that look like valleys and old lakebeds, suggesting liquid water once churned on the planet's surface. And yet that surface is really cold, at -80 degrees Fahrenheit, on average.

One possible explanation is that the Martian atmosphere used to be full of carbon dioxide creating enough greenhouse effect to heat up the surface. But postdoctoral researcher Tyler Robinson said simulations haven’t been able to show how that’s possible.

“The problem is you can only pack so much CO2 into the atmosphere of a planet before it stops being such a good greenhouse gas and actually starts to work to cool the planet,” Robinson said.

So Robinson, working at the UW, and a research team from Penn State tried out some other scenarios. Eventually they figured out that adding a whiff of molecular hydrogen, belched up from Martian volcanoes, would do the trick. Robinsons says it would add another layer of heat-trapping effects.

“The analogy that I like to make is that when it’s really cold at night, you might put on a pair of flannel pajamas, and you’d also put a really thick comforter on the bed,” he said.

Carbon is like the blanket in that scenario, and hydrogen is like the jammies.

The finding bolsters one of the two leading theories of how Mars could have been so wet. The other suggests heavy bombardment by meteors temporarily heated up the planet enough for water to flow.

A warm, wet Mars is especially intriguing because it could have, at one time, provided the right conditions for life to form.