USGS: Ice Sheets on Mars Hint at Past Snowfall

Jan 12, 2018

A Flagstaff geologist found eight massive ice sheets on the planet Mars, using images from a NASA spacecraft. It’s the first detailed look at the layered structure of Mars’ ice. KNAU’s Melissa Sevigny reports. 

In this false-color image, an exposed layer of water ice appears in blue.
Credit NASA/JPL/University of Arizona/USGS

Colin Dundas of the U.S. Geological Survey is lead author of the study. He found thick sheets of nearly pure water ice, exposed to the surface by erosion on steep cliffs.

The exposed glaciers are miles wide and in some cases more than 300 feet thick. "It’s quite clean overall," Dundas says, "it has some amount of dust or dirt or debris mixed in, but for the most part it’s just a thick sheet of ice that we believe originated as snowfall in the geologically recent times."

Snow is rare on Mars today. But Dundas thinks it was more common in the past, when the planet’s axis had a different tilt. He says studying these ice sheets could give clues to Mars’ past climate.

Dundas’ paper appears today in the journal Science.