Martian sand dunes are blowing within the wind — however slowly, and primarily based on elements that do not have an effect on sand motion right here on Earth.
Scientists tracked the motion of almost 500 particular person dunes, all utilizing knowledge gathered by NASA’s Mars Reconnaissance Orbiter. By finding out the motion of all that sand, the researchers had been capable of evaluate the interplay between wind and sand on the Crimson Planet with the identical interplay on Earth.
“On Mars, there merely isn’t sufficient wind vitality to maneuver a considerable quantity of fabric round on the floor,” lead creator Matthew Chojnacki, a planetary scientist on the College of Arizona, mentioned in an announcement. “It would take two years on Mars to see the identical motion you’d sometimes see in a season on Earth.”
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Chojnacki and his colleagues used photos taken by HiRISE, a specialised digicam on board the Mars Reconnaissance Orbiter that photos the floor of Mars with extremely detailed pictures. These pictures embody loads of scenes of sand dunes rippling throughout the planet.
Scientists are significantly within the sand dunes as a result of they signify areas the place the floor is altering sufficient that the identical materials is not getting continually blasted by the cruel atmosphere. “If you do not have sand shifting round, which means the floor is simply sitting there, getting bombarded by ultraviolet and gamma radiation that will destroy advanced molecules and any historic Martian biosignatures,” Chojnacki mentioned.
By choosing pairs of photos that confirmed the identical patch of floor years aside, the crew was capable of measure how briskly every dune was shifting. That evaluation means that Martian sand dunes transfer at a fraction of the velocity of these discovered on Earth — which is sensible given how a lot thinner an environment the Crimson Planet boasts than Earth.
What was much less predictable was that only a handful of spots would sport considerably sooner sand motion: Syrtis Main, the Hellespontus mountains and a area known as the north polar ergs. The researchers assume that the comparatively quick sand motion right here could also be brought on by dramatic modifications in floor elevation and temperature that come up the place various kinds of floor options neighbor one another. That is not a scenario that prompts winds right here on Earth.
“These will not be elements you’d discover in terrestrial geology,” Chojnacki mentioned. “On Earth, the elements at work are completely different from Mars. For instance, floor water close to the floor or crops rising within the space retard dune sand motion.”
The analysis is described in a paper revealed March 11 within the journal Geology.
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