Scientists Discover Concealed Glaciers on Mars at Mid-Latitudes



 the actual surface and without debris
Three Martian craters: the actual surface is on the left, and without debris is on the right.More images of concealed Martian glaciers and similar features on Earth are online. 









Developers of the Shallow Radar had the mid-latitude aprons in mind, along with Mars' polar-layered deposits, long before the instrument reached Mars in 2006.

"We developed the instrument so it could operate on this kind of terrain," said Roberto Seu of Sapienza University of Rome, leader of the instrument science team. "It is now a priority to observe other examples of these aprons to determine whether they are also ice."


"There's an even larger volume of water ice in the northern deposits," said the Jet Propulsion Laboratory's Jeffrey J. Plaut, whose paper on that discovery has been accepted for publication by the journal Geophysical Research Letters. "The fact that these features are in the same latitude bands--about 35 to 60 degrees--in both hemispheres points to a climate-driven mechanism for explaining how they got there."

The rocky-debris blanket topping the glaciers has apparently protected the ice from vaporizing as it would if exposed to the atmosphere at these latitudes.

"A key question is 'How did the ice get there in the first place?'" said James W. Head of Brown University.

"The tilt of Mars' spin axis sometimes gets much greater than it is now, and climate modeling tells us that ice sheets could cover mid-latitude regions of Mars during those high-tilt periods," said Head. He believes the buried glaciers make sense as preserved fragments from an ice age millions of years ago.

"On Earth," said Head, "such buried glacial ice in Antarctica preserves the record of traces of ancient organisms and past climate history."

Images of concealed Martian glaciers and similar features on Earth are online.