Mysterious hills on Mars could be evidence of the Red Planet’s ancient ocean

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Some of the Martian hills and mesas on the northern plains of the Red Planet. Inside these eroded hills are layers of clay created by liquid water. | Source: ESA/DLR/FU Berlin

Thousands of hills and mounds on Mars were found to contain layers of clay minerals that formed when flowing water interacted with the rocks while the northern reaches of Mars were flooded.

“This research shows us that The climate of Mars “In the distant past, things were dramatically different,” Joe McNeil of the Natural History Museum in London said in one opinion. “The hills are rich in clay minerals, meaning liquid water must have been present in large quantities on the surface almost four billion years ago.”

Mars is a planet of two halves. In the south there are ancient plateaus, in the north there are eroded, mostly low-lying plains in which a large body of water probably once existed. In fact, there is now overwhelming evidence that Mars once existed warmer and wetwith Rivers, lakes and possibly even Oceans that existed almost four billion years ago.

Now researchers led by McNeil have found further evidence of a northern sea in the form of more than 15,000 mounds and mounds up to 500 meters high that contain clay minerals.

Related: The ocean’s water supply may be buried in Mars – but can we get there?

To Earth – for example, in the western United States – we find such mounds in the form of hills and mesas in desert areas where rock formations have been eroded by the wind over millions of years.

On Mars we also find hills and mesas. McNeil’s team studied a region the size of the United Kingdom that is filled with thousands of these hills. They are all that remains of a highland area in Chryse Planitia north and west of the southern highland area known as Mawrth Vallis, which has retreated hundreds of kilometers and been eroded by water and wind. Chryse Planitia was the landing site of NASA‘S Vikings 1 Mission in 1976 and is a vast lowland region created by an ancient impact.

Using high-resolution images and spectral composition data from NASA’s HiRISE and CRISM instruments Mars reconnaissance orbiteras well as the European Space Agency‘S Mars Express And ExoMars Trace Gas OrbiterMcNeil’s team showed that Mars’ hills and mesas are made of layered deposits, and that beneath these layers are up to 1,150 feet (350 m) of clay minerals, formed when liquid water penetrates and interacts with the rock over millions of years .

“[This] shows there must have been a lot of water on the surface for a long time,” McNeil said. “It is possible that it came from an ancient northern ocean on Mars, but that is an idea that is still controversial.”

Immediately beneath the clay layers lie older rock layers that do not contain any clay; Above the clay layers lie younger rock layers that also contain no clay. It seems clear that the clay layers come from a specific wet period in Mars’ history, during the Noachian era of the Red Planet (which spans). Time 4.2 to 3.7 billion years ago), a geological period characterized by the presence of liquid water on Mars.