Evidence of ancient ice age found on Mars' north pole

BOULDER, Colo., May 26 (UPI) -- New analysis of polar deposits on Mars has revealed evidence of an ancient Martian ice age. The analysis was done by researchers at the Southwest Research Institute using data collected by NASA's Mars Reconnaissance Orbiter.

"We found an accelerated accumulation rate of ice in the uppermost 100 to 300 meters of the polar cap," Isaac Smith, a postdoctoral researcher at SwRI, said in a press release.

Smith is the lead author of a new paper on the revelation, published this week in the journal Science.

"The volume and thickness of ice matches model predictions from the early 2000s," Smith added. "Radar observations of the ice cap provide a detailed history of ice accumulation and erosion associated with climate change."

Researchers say factors that influence ice age cycles on Earth -- the planet's tilt and orbit -- are even more significant on Mars. The tilt of the Martian axis shifts as much as 60 degrees over the course of several million years. Over a similar time period, the Earth's axis shifts just a couple of degrees.

"Because the climate on Mars fluctuates with larger swings in axial tilt, and ice will distribute differently for each swing, Mars would look substantially different in the past than it does now," Smith explained. "Furthermore, because Mars has no oceans at present, it represents a simplified 'laboratory' for understanding climate science on Earth."

Thanks to the data collected by MRO, researchers have been able to plot the accumulation of ice at Mars' poles, which can be used to reconstruct the changes in the Red Planet's orbital eccentricity, axial tilt and rotation.

"Studying ice on Mars also is important to the future of human exploration of the Red Planet," Smith said. "Water will be a critical resource for a martian outpost."