Mars Express Reveals Climate Evolution On Red Planet

June 7, 2012
Image Caption: This computer-generated perspective view was created using data obtained from the High- Resolution Stereo Camera (HRSC) on ESA’s Mars Express. Centered at around 7°N and 353°E, this image has a ground resolution of about 26 m per pixel. A part of Danielson crater dominates this view with the detailed relief of the yardangs being interrupted by the 30 km-long field of dark dunes. The uniform thickness in the alternating sedimentary layers provides evidence for the theory that periodic changes in the climate of Mars occurred, possibly due to changes in the planet’s rotation axis. Credits: ESA/DLR/FU Berlin (G. Neukum)

Lee Rannals for redOrbit.com

ESA announced on Thursday that Mars Express has taken images of a crater on Mars which may show evidence that the planet underwent fluctuations in its climate due to changes in its rotation axis.

ESA’s spacecraft used its high-resolution stereo camera at the Arabia Terra region of Mars on June 19, 2011 to image the Danielson and Kalocsa craters.

Danielson crater is filled with layered sediments, and within the crater are peculiarly layered buttes, which are known as yardangs.

Yardangs are hills carved from bedrock or any consolidated or semi-consolidated material by abrasive dust and sand particles carried in the wind.

These structures are seen on Earth in desert regions, with examples in North Africa, Central Asia and Arizona.

ESA believes the sediments in Danielson crater were cemented by water, maybe from an ancient reservoir.

Scientists theorize that strong north-northeasterly winds both deposited the original sediments and then caused their subsequent erosion in a drier period later on in Martian history.

The 18.50 mile-long field of dunes can be seen bisecting the yardangs and is thought to have formed at a later epoch, according to ESA.

Danielson’s crater floor shows evidence for a series of alternating sedimentary layers with uniform thickness and separation.

Some scientists believe this indicates periodic fluctuations in the climate of Mars, which is triggered by regular changes in the planet’s axis of rotation.

According to ESA, the different layers would have been laid down during different epochs. The Kalocsa crater shows a different topography.

In the Kalocsa crater, no layered sediments can be seen, which is due to the higher altitude of its floor, ESA said.

The space agency said that another hypothesis is that the Kalocsa crater is younger than its neighbor, and was created when water was not present anymore.

Source: Lee Rannals for redOrbit.com

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