Just ten million years ago (a geological eyeblink), Mars could've had an ice age. Even cooler, it may have been one of several, meaning the planet underwent freeze/thaw periods much like those here on Earth. And that means — you guessed it — the chances for liquid water and life on the Red Planet just went way up. Cooler still, those glaciers likely had liquid water near their base, and seeping into the rocks below. A new study in the journal Geology based on images from the Mars Reconnaissance Orbiter has found compelling evidence that sheets of ice between 1 and 2.5 kilometers thick grew near the Martian equator some time in the recent past.

Even if Mars has had steadily sub-freezing weather for a long time now, glaciers can provide the kind of cover needed to maintain liquid water. We know from Earthling ice sheets that as you go deeper inside them, the temperature tends to go up. Down near the bottom the crushing pressure of miles of ice piled on top can cause melting. Ponds and lakes can even form.

The researchers — headed by Jay Dickson of Brown University — think the same thing could've happened on Mars:

After examining stunning high-resolution images taken last year by the Mars Reconnaissance Orbiter, the researchers have documented for the first time that ice packs at least 1 kilometer (0.6 miles) thick and perhaps 2.5 kilometers (1.6 miles) thick existed along Mars' mid-latitude belt as recently as 100 million years ago. In addition, the team believes other images tell them that glaciers flowed in localized areas in the last 10 to 100 million years - akin to the day before yesterday in Mars' geological timeline.

This evidence of recent activity means the Martian climate may change again and could bolster speculation about whether the Red Planet can, or did, support life.

"We've gone from seeing Mars as a dead planet for three-plus billion years to one that has been alive in recent times," said Jay Dickson, a research analyst in the Department of Geological Sciences at Brown and lead author of the Geology paper. "[The finding] has changed our perspective from a planet that has been dry and dead to one that is icy and active."

Images from Mars orbiter.
Source: Geology via Science Blog