“Enough to fill the Red Sea”

There is also water in the form of ice on the equator of Mars. The European Space Agency (ESA) announced this today. The ice will extend for miles underground. Water ice has previously been found at the poles of Mars, but such a reserve has never been discovered before in this part of the planet.

More than 15 years ago, Mars Express first studied the Medusae Fossae Formation (MFF) on the Martian equator. The Medusae Fossae Formation is hundreds of kilometers wide and several kilometers high. It is located on the border between the highlands and lowlands of Mars. During this investigation, the spacecraft revealed huge deposits up to 2.5 kilometers deep.

However, it was not clear from these early observations what exactly these deposits were composed of. The structure was seen to be relatively transparent to radar and to have a low density, both characteristics seen in glacial deposits. However, scientists were able to rule out a “drier” possibility involving massive accumulations of wind-blown dust, volcanic ash or sediment. But new research now has an answer to this pressing question.

“We have re-examined the MFF using more recent data from Mars Express's MARSIS radar. Not only do we now know what the sediment is made of, but we also know that it is much thicker than we thought: up to 2.3 miles thick,” said Thomas Watters of the Smithsonian Institution. (3.7 km).” He is the lead author of both the new research and the original 2007 study. “It's exciting that the radar signals match what we expect to see from ice sheets. For example, it can be compared to the signals we see from the polar caps of Mars, which we know are very rich in ice. If the ice in the MFF melts, it could cover the entire planet in a layer of water 1.5 to 2.7 meters deep, enough to fill the Red Sea here on Earth. This is the largest amount of water ever found in this part of Mars.

Although Mars now appears to be a dry world, this new research once again shows that the planet's surface is littered with signs that water was once abundant. Dry river channels, ocean floors, ancient lakes and valleys carved by water have already been found. Scientists have also discovered large amounts of ice on Mars, such as massive polar ice caps, buried glaciers near the equator, and near-surface ice weaving through the Martian soil.

“This latest analysis helps us better understand the formation of Medusae Fossae, but at the same time it raises as many questions as it answers,” said Colin Wilson, ESA project scientist for Mars Express and ESA's ExoMars Trace Gas Orbiter (TGO). “. “How long ago did these icy deposits form, and what did Mars look like at that time?” If there is further confirmation that it is water ice, these massive deposits could change our understanding of the climate history of Mars.

Any ancient water reservoir is also an interesting target for future human or robotic exploration. Missions to Mars must land near the planet's equator, far from ice-rich polar caps or glaciers at high latitudes. They need water as a resource, so finding ice in this region is almost a necessity for human missions to the planet. “Unfortunately, these MFF deposits are covered in hundreds of meters of dust, making them inaccessible for at least the next few decades. But every amount of ice we find helps us get a better idea of ​​where Martian water once flowed and where it might be found.” We need it today if we need it in the future.