Specialists of Colorado University in Bouldere opened the appearance reasons on the surface of Mars of unusual canyons – “spiders”. Article in Icarus log claims that canyons appear because of thawing and the reverse freezing of artificial ice.
Appear and grow
The probe MRO photographed regions about the South Pole of Mars. In pictures scientists found canyons of the unusual form – with accurately designated center and cracks which dispersed from it in different directions.
The research of the pictures made at different times showed that canyons – “spiders” increase in sizes over time, however quite often objects disappeared from the surface of Mars. Shooting was continued with use of the camera HiRISE to receive better photos.
Canyons – “spiders” begin to be created in the spring. Scientists believe that the reason of their appearance – thawing of artificial ice, the frozen carbonic acid which afterwards again freezes. A part of ice which covers sandy dunes on Mars gets warm in the spring and turns into gaseous state – carbon dioxide. The bubble under a glacier surface is formed of it.
Pressure in a bubble grows, ice bursts, and carbon dioxide escapes in the atmosphere of Mars. Together with gas a large amount of sand which destroys environmental space is thrown out – works like the sanding machine.
As a rule, canyons remain throughout the Martian winter, gradually extending and increasing in sizes. However so far scientists don’t know whether they will be able to cover the sands covering certain regions of Mars them. At the same time on the North Pole of Mars of similar canyons isn’t present – there sand any more, and it can fill cracks directly.