Modern Mars is a barren world, drier than any desert on Earth,media reported. But geological evidence suggests that this has not always been the case — in the distant past, there was flowing water on the red planet. It has long been thought that ancient Mars was warm and humid, but a new study has found that it is covered by ice sheets and that most of the water is runoff from glaciers.
There is plenty of evidence that Mars was once wetter than it is now. Through orbiters and earth-based probes in the Martian sky, we have seen traces of the planet’s oceans, coastlines, lakes, rivers, and flood plains.
All this led scientists to speculate that Mars was once very similar to Earth, with warm, mild climates and regular rainfall. But now, a new study from the University of British Columbia finds that the story doesn’t explain all the structures seen.
“In the last 40 years, since the first discovery of the Martian valleys, the assumption is that there have been rivers on Mars that have eroded and created all of these valleys,” said Anna Grau Galofre, the study’s lead author. If you look at the Earth from a satellite, you’ll see many valleys: some are formed by rivers, some by glaciers, some by other processes, each with its own unique shape. Mars is similar, and each valley looks very different, suggesting that there are many processes for carving them. “
For the study, the researchers used an algorithm to study the shape of the valleys and calculate the erosion processes that most likely to form them. The team is reported to have used the algorithm to analyze more than 10,000 valleys on Mars. As a result, they found that only a small portion of the valley networks studied matched the expected pattern of surface water erosion, while many others resembled path circulation channels formed under glaciers.
This scenario also helps to close a major plot loophole in the previous warm-wet hypothesis. When these passages formed — about 3.8 billion years ago — the sun was much quieter, and Mars should have a rather cold climate.
“Climate models predict that the ancient climate of Mars was much colder during the period when the valley network was formed,” said researcher Garu Galofre. “
Much of Mars is icy rather than warm, a view that seems to have poured cold water on the red planet’s possibility of ancient life — but the team says the opposite is true. They say the ice sheet stabilizes the water supply and protects any life from solar radiation.