3,4 billion years ago, two giant asteroid fell one after the other in the Martian ocean with a break of a few million years, and each of them has caused a giant tsunami – a wave height of up to 120 meters, penetrated deep into the mainland for hundreds of kilometers. This fact has found an international group of researchers, led by Alexis Rodriguez of Planetologicheskogo Institute (USA), the study of geomorphological features of the northern valleys of Mars, where, for a long time according to the observations, in ancient times there was the ocean. The details of this work, the scientists told the paper, Published on May 19 in the journal Scientific Reports
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However, such mega-tsunami in those days were not anything special, and
asteroids cause them bombarded the planet Mars, or type Earth about once every three million years.
On Earth, too, traces of these attacks, but erosion of their long time carefully concealed. On Mars, the same for billions of years ago, lost its atmosphere, erosion has affected the surface is not so much, and craters that emerged after the fall of the asteroid can be seen today – each of them has a diameter of about 30 km
advanced the hypothesis. two mega-tsunami, scientists have actually resolved the puzzle, which since the last century called into question the very existence of the Martian ocean. Then Timothy Parker, a geologist at NASA’s, found on Mars some line erosion, encircling the planet. These lines were similar to those seen and learned in the world, when I was looking in the deserts of the traces of ancient lakes. According to Parker, billions of years ago, a third of the Martian surface has been hidden under the ocean waters. Then something happened, and
ocean began to shrink like shagreen leather. Reduced to a certain limit, it lasted so for some time, and then disappeared completely
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As a proof of Parker led made yet “Viking” (a spacecraft NASA) pictures coastlines original and “curled” ocean
These photos are not convinced by the scientific community, as. shots were too low resolution. To confirm the existence of an ancient ocean, it was necessary to prove that its coastlines – and internal and external – are at the same height, because the concept of “sea level” remains so even on Mars. Everyone was waiting for the final verdict of the orbiter NASA Mars Global Surveyor (this machine came to a circular orbit and began observations in September 1997 and completed its work in November 2006): he made clearer photos with ten-height resolution
.
The device, however, the dispute is not resolved, and gave a new surprise:
photographs showed that all the inner ring of the coastline is approximately at the same height, but different parts of the external rings differ in their heights, and sometimes the difference reaches 8 km!
This data is put scientists in a deadlock
And here the solution -. Two mega-tsunami that carried ocean waters at different heights and thus violated inviolable “rule” the sea level.
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All of these events occurred in the period of global change with Mars, in those times when he out-paced, “living” planet, which could well have arisen – and maybe even born – life gradually began to turn into a dead desert, freezing, losing air and water. The first mega-tsunami, according to the authors, had a more or less good times, when it was still relatively warm and the water brought to land a giant wave came out in liquid form. Water left behind the channels through which it comes back. These channels, or rather their traces on the surface of Mars have so far.
The next blow came at a time when the climate on Mars became much colder. The second wave proved petals frozen ice, which, of course, is not returned and stayed there, anywhere. Apparently, this ice over the past billions of years, have never melted.
According to the form of ice emissions, they pronounced borders scientists came to the conclusion that the water in the Martian the ocean was salty
«salt, even very cold water -. says Alberto Feira from Cornell University, one of the work of the co-authors – could become a haven for life forms, if by that time there on Mars, and if so, then these icy petals are very good candidates to search for ancient biological traces »
He was echoed by the head of the study Alexis Rodriguez:.” We have already identified several flooded these tsunami areas where formed lake leaving behind sediments. We intend to characterize these areas and to assess their potential for further research on the site of robots or humans. »
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