September 5, 2013
Images Of Becquerel Crater Offer Insight Into Martian History
Lee Rannals for redOrbit.com - Your Universe Online
A new image taken by the high-resolution stereo camera on the European Space Agency's (ESA) Mars Express shows an area on the Red Planet that features radiating patterns.The mosaic is composed of four images of the Becquerel crater located in Arabia Terra, which is an area between the southern highlands and the northern lowlands of Mars. The Becquerel crater is the largest feature in the picture with a diameter of about 100 miles and a depth of 2 miles.
ESA said the presence of minerals in the crater suggest that water may have once existed there in a vast crater lake before evaporating.
"It is likely that the entire crater floor was once covered with such sediments, but over billions of years much of it has been eroded away by wind, leaving just a polished, rounded mound behind," ESA reported.
Arabia Terra features similar light-toned sulphate-bearing deposits, including some in the crater walls themselves. Experts say this points to a large-scale process that affects the entire region. The crater contains a mound that rises a little over half a mile above the crater flood and comprises hundreds of layers of light-toned sediments.
ESA said that although water does not flow on Mars anymore, wind still plays a crucial role in shaping the environment. The dark material sitting within the Becquerel crater most likely blew in from other places, perhaps even from volcanic eruptions.
"A number of tiny craters with tail-like structures lie along this track: their raised rims influence the flow of wind over them such that the material immediately downwind of the crater remains undisturbed in comparison to the surrounding, exposed plains," ESA officials wrote in a description of the image.
The mosaic features another streak of dust along a radial path out of Becquerel crater that traces out a gentle topographic depression, beyond the eroded rim of the old crater. Dark sediments inside the small crater towards the far left of the main image were blown out in a similar direction by the powerful prevailing wind.
Wind continues to bring changes to the Martian surface, exposing ancient rock formations as well as eradicating younger features. Studies of these wind-blown patterns allow scientists to peek into the history of Mars.
Princeton University scientists believe Mount Sharp, where NASA's Curiosity rover is currently heading, was formed by wind. They said back in May that the mountain formed as a result of Mars' dust atmosphere, rather than a lake as some scientists had proposed. The team said Mount Sharp emerged as strong winds carried dust and sand into the 96-mile-wide crater in which the mound sits.