Blue planet? Ice discovery at Mars equator offers new insight

Huge tracts of ice could lie under equatorial regions of Mars, scientists said on Thursday, challenging current understanding of the planet.

New radar data shows that the entire planet would be engulfed in water if the ice deposits melted, the international team of US and European scientists said.

They re-examined the Medusae Fossae Formation (MFF) on the planet, using data from the Mars Express orbiter’s Marsis radar, and now believe there are major deposits of ice under the surface of the Red Planet.

“We’ve explored the MFF again … and found the deposits to be even thicker than we thought, up to 3.7km thick,” said lead author Thomas Watters of the Smithsonian Institution.

“Excitingly, the radar signals match what we’d expect to see from layered ice, and are similar to the signals we see from Mars’s polar caps, which we know to be very ice-rich.”

The deposits had been identified previously but it was not known what they were made from.

“This latest analysis challenges our understanding of the Medusae Fossae Formation, and raises as many questions as answers,” said Colin Wilson, European Space Agency project scientist for Mars Express.

The MFF consists of several wind-sculpted features measuring hundreds of kilometres across and several kilometres high.

If melted, the ice could cover the planet in a layer of water up to 2.7m deep, or enough to fill Earth’s Red Sea.

“How long ago did these ice deposits form, and what was Mars like at that time? If confirmed to be water ice, these massive deposits would change our understanding of Mars' climate history,” Mr Wilson said.

“Any reservoir of ancient water would be a fascinating target for human or robotic exploration.”

Mars Express data showed the MFF to be relatively transparent to radar and low in density, both characteristics of icy deposits.

The new results suggest layers of dust and ice, topped by a protective layer of dust or ash several hundred metres thick.

The extent and location of the icy deposits would also make them potentially very valuable for our future exploration of Mars.

“Unfortunately, these MFF deposits are covered by hundreds of metres of dust, making them inaccessible for at least the next few decades,” the team said.

“However, every bit of ice we find helps us build a better picture of where Mars’s water has flowed before, and where it can be found today.”

Missions to Mars will need to land near the planet’s equator, far from the ice-rich polar caps or high-latitude glaciers.

They will need water as a resource, so finding ice in the region opens up new dreams of exploration.