Using a radar capable of penetrating the ground, a group of scientists detected an enormous amount of frozen water between the layers of sand at the north pole of Mars. This deposit contains so much ice that if it melts and rises to the surface, it could leave much of the planet submerged.
The discovery is a kind of deposit of multiple layers of ice, which is mixed with sand, and formed over hundreds of millions of years. It is located about two kilometers below the planet's surface and, before this new study, scientists thought it was composed mainly of sand dunes.
But now, the device used for its detection suggests that it is filled with more frozen water than sand. As a result, this may be the third largest water reservoir on the red planet, along with two other layers of polar ice caps. An article containing these findings was published in the scientific journal Geophysical Research Letters.
These new observations were made by a device called SHARAD (Shallow Radar), an instrument on board the Mars Reconnaissance Orbiter, from NASA. SHARAD emits radar waves capable of penetrating the surface, allowing the internal structures of these layers to be seen.
These observations revealed the existence of a series of horizontal blocks, rich in ice, that were trapped between layers of sand. As the press release points out, if the ice melts and leaks to the surface, "it would be equivalent to a layer of water that would be able to envelop the entire territory of Mars at least 1,5 meters deep".
How did the ice come about?
SHARAD data shows that the frequency and volume of the ice sheets increased as they approached the north pole. In one region, for example, researchers detected two layers of sand more than 40 kilometers wide that had an ice layer between 50 and 100 meters deep.
These buried structures are the remains of old ice caps, which were created and ended up being buried during warmer periods, according to the published article. Therefore, this part contains a historical record of the Martian climate. The layers of ice are like the rings of a tree, showing the growth and retreat of the old polar caps over the years.
As with Earth, Mars experienced several, say, icy periods. During the warmer seasons, the sand enveloped the ice layers, protecting them from the sun and, in turn, preventing them from evaporating into the atmosphere.
Water in other locations
The new discovery may also tell us a little more about the frozen water located elsewhere on Mars, especially in the lower latitudes. Jack Holt, co-author of the study and a researcher at the University of Arizona, used SHARAD to confirm the presence of massive glaciers in the middle latitudes of Mars. These glaciers are almost completely composed of frozen water, but are hidden by the surface materials.
“Surprisingly, the total volume of water from these buried polar deposits is approximately the same as that found in glaciers buried in the low latitudes of Mars. And both are the same age, ”said Holt.
As we can see, the red planet has a large amount of water that can facilitate the way humans want to colonize the planet. Perhaps this is what the scientists were hoping to find in order to start a mission, in an attempt to make life survive on Mars.