Deposits of water ice stretching over two miles below the ground have been discovered at Mars’ equator

Deposits of water ice stretching over two miles below the ground have been discovered at Mars’ equator. It’s thought that if melted there is enough water in the newly found deposits to cover the entire surface of the red planet in a layer of water 1.5 to 2.7 meters deep.

Buried ice will be a vital resource for the first people to set foot on Mars, according to NASA. As well as for drinking, water could be used to make rocket fuel, but it could also reveal the climate history of Mars. That makes the new discovery potentially valuable because missions to Mars will need to land near the planet’s equator.

Valuable Discovery

The discovery, announced in a paper published today in the journal Geophysical Research Letters, was made using data from MARSIS radar on board the European Space Agency’s Mars Express spacecraft. It’s been orbiting the red planet for almost 20 years.

The deposits were found in Medusae Fossae Formation, the planet’s largest sedimentary deposit, which has long been mysterious to scientists. Until now, thought to be the largest single source of dust on Mars, the MFF is about the size of India, according to ESA.

Dust-Covered Ice

“We’ve explored the MFF again using newer data from Mars Express’s MARSIS radar and found the deposits to be even thicker than we thought,” said Thomas Watters of the Smithsonian Institution, lead author of both the new research and the initial study of the MFF in 2007. The deposits are 2.3 miles (3.7 km) thick and covered by a protective layer of dry dust several hundred meters thick.

“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.”

Ancient Reservoir

This is the most water ever found close to Mars’ equator, but it’s not the first time ice has been found on the dusty planet. It’s known that water ice exists at the planet’s polar caps, in buried glaciers near the equator, and in the Martian soil.

“This latest analysis challenges our understanding of the Medusae Fossae Formation, and raises as many questions as answers,” says Colin Wilson, ESA project scientist for Mars Express and the ESA ExoMars Trace Gas Orbiter (TGO). 

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

Inaccessible For Decades

Although technically interesting for human exploration plans, the discovery of water ice close to the equator of Mars comes with one downside—it’s buried under a lot of dust. “Unfortunately, these MFF deposits are covered by hundreds of meters of dust, making them inaccessible for at least the next few decades,” said Colin Wilson, ESA project scientist for Mars Express. 

“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.”

Wishing you clear skies and wide eyes.