Melting water under glacial ice , and not by free-flowing rivers as previously thought, was what carved out the vast number of valley networks that crisscross the surface of Mars.
This is what a new study from the University of British Columbia (UBC) in Canada suggests, published this Monday in the journal Nature Geoscience .
According to the conclusions of this new study, then, at the origins of Mars there were no rivers, rains and oceans. It was not a hot and humid place. According to lead author Anna Grau Galofre , a former PhD student in the Department of Earth, Ocean and Atmospheric Sciences:
During the last 40 years, since the valleys of Mars were discovered, rivers were supposed to once flow over Mars, eroding and originating all of these valleys. But there are hundreds of valleys on Mars, and they are very different from each other. If you look at Earth from a satellite, you see many valleys: some made by rivers, some by glaciers, some by other processes, and each type has a distinctive shape. Mars is similar in that the valleys look very different from each other, suggesting that many processes were at play to carve them out.
To reach this conclusion, new techniques have been developed to examine thousands of Martian valleys. Martian valleys were also compared to subglacial channels in the Canadian Arctic Archipelago and found striking similarities. In total, the researchers analyzed more than 10,000 Martian valleys , using a new algorithm to infer their underlying erosion processes.
Valleys would have formed 3.8 billion years ago on a planet that is further from the sun than Earth, during a time when the sun was less intense.