Evidence of Martian ice age discovered

A team of scientists at the Southwest Research Institute have been pouring over data collected by the Mars Reconnaissance Orbiter and report that they have found evidence of an ice ago in the polar deposits of Mars. The team says that the same forces that drive ice ages here on Earth drive ice ages on Mars. Those forces are long-term cyclical changes in the orbit and tilt of the planet that directly affect how much solar radiation the planet receives at each latitude.

"We found an accelerated accumulation rate of ice in the uppermost 100 to 300 meters of the polar cap," said Dr. Isaac Smith, a postdoctoral researcher at SwRI and lead author of a paper published in the May 27 issue of Science. "The volume and thickness of ice matches model predictions from the early 2000s. Radar observations of the ice cap provide a detailed history of ice accumulation and erosion associated with climate change."

The team says that Mars has seasonal cycles along with longer cycles that have impact on the distribution of ice on the planet. While these changes are not severe on Earth on Mars the scientists say that the Red Planet's tilt can change as much as 60-degrees on a scale of hundreds of thousands to millions of years. Earth's tilt only varies about 2-degrees over that same massive time scale.

The team says that study has revealed that the ice thickness was about 87,000 cubic kilometers of accumulation at the poles since the end of the last ice age some 370,000 years ago. Most of that icy material was accumulated at the Martian north pole. "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," said Smith. "Furthermore, because Mars has no oceans at present, it represents a simplified 'laboratory' for understanding climate science on Earth."

SOURCE: swri