Canadian researchers put forward the hypothesis that billions of years ago Mars was covered with an ice shield. It goes against the dominant theory that in ancient times the red planet was a humid climate. In the new version, most Martian valleys is not dry river beds, and the traces of the channels of melt water under glaciers. Ice protect water from harmful solar radiation, therefore, existed on the early Mars conditions were quite suitable for life, according to experts.
Researchers from the University of British Columbia and the University of Western Ontario (Canada) put forward the hypothesis that many of the Martian valleys formed by melting water under ancient glaciers. This was reported in the journal Nature Geoscience.
According to the dominant to date, the hypothesis that early Mars was warm and wet. Flowed a river, they fell into seas and oceans, and Istaravshan water falls to the surface as precipitation. Under the new version of the canadian team of scientists, it was not so in ancient times the Red planet was covered with ice, and soil erosion in most cases caused the melt water, formed by glaciers.
As proof of their hypothesis, the scientists show a surprising similarity of the images of most Martian valleys and drainage channels of melt water under the glaciers of the uninhabited Devon island in the Canadian part of the Arctic archipelago.
“over the past 40 years, since the opening of valleys on Mars, it was assumed that they all once were formed by erosion caused by rivers. But on Mars the hundreds of valleys, and they look very, very different from each other. If you look at the Earth from a satellite, you can see many of the valleys: some were formed by rivers, others glaciers, the third — as a result of exposure to other processes,” says main author, a former graduate student of the Department of Earth Sciences, the ocean and the atmosphere at the University of British Columbia Anna Grau Galore.
According to researchers, the landscape of Devon island is the closest terrestrial analogue to early Mars is cold, dry and very cold polar desert. After comparison of under-ice channels Devon and most Martian valleys prigly scientists to the conclusion that the latter is not considered a parched riverbeds of the rivers, and traces the impact of melt water on the soil of the red planet. In total, the researchers analyzed more than 10 thousand Martian valleys, revealing the character of soil erosion.
“As we were able to detect only a small part of the network of valleys has a pattern typical of erosion caused by surface water, which obviously contradicts the conventional wisdom. Use in studying the surface of Mars geomorphology for a thorough and hon��arnoga reconstruction of the nature and characteristics of the evolution of the planet — the approach, frankly, is revolutionary,” says another study author, lecturer at the Department of Earth Sciences, the ocean and the atmosphere at the University of British Columbia mark Jellinek.
According to the theory of canadian researchers, Martian rivers could not flow over the surface of the planet. Valley, whose age has about 3.8 billion years, formed at a time when the intensity of the Sun was much lower, and the Mars is from a star much further away than the Earth. Therefore, the Red planet was covered with glaciers.
“using climate modeling we can assume that during the formation of the network of valleys the climate on Mars was much colder. We tried to make a complete picture and to put forward a hypothesis not previously been considered: the channels of outflow of water and the network of valleys formed under the ice sheet,” said Grau Galore.
Existed on early Mars climatic conditions were quite suitable to sustain life, the researchers said.
The surface layer of ice protected underneath the water from solar radiation in the absence of a magnetic field, which disappeared on this planet several billion years ago.
Designed to explore Mars analytical tools scientists will use to study Earth’s early history.
“we can Now in detail to reconstruct the history of global glaciation on the Earth from 1 to 5 million years ago, as well as to study the onset and retreat of ice sheets that occurred at least 35 million years ago — long before the times which are the most ancient of extracted ice cores,” concluded mark Jellinek.
