Martian polar-layered deposits may bear imprint of changes in Red Planets orbit

February 4th, 2009 - 2:29 pm ICT by ANI  

Washington, Feb 4 (ANI): A new study has suggested that the polar-layered deposits on Mars may bear an imprint of variations in the Red Planets orbit.

The study was led by J. Taylor Perron and Peter Huybers of the department of Earth and Planetary Sciences, Harvard University.

Climate records in ice cores and ocean sediments record temperature changes, including repeated ice ages that bear a clear mark of long-term variations in the Earths orbit.

In their study, Perron and Huybers tried to determine whether the polar ice caps on Mars contain a similar record of orbital changes.

The Martian polar caps contain hundreds of meters of layers composed of mixed ice and dust, and scientists have speculated that these layers formed in response to variations in orbital characteristics like the tilt of Mars rotational axis, which controls the intensity of the seasons.

Perron and Huybers used spacecraft images of exposed layers and elevation measurements to construct virtual cores through the north polar cap.

Their analysis of these cores revealed repeating layers 1.6 meters (about 5 feet) thick in many areas of the polar cap.

Because the age of the polar caps is unknown, it is not currently possible to determine whether the layering formed in response to orbital variations, contrary to the conclusions of several previous studies.

To confirm an orbital cause, repeating layers with multiple thicknesses, corresponding to the multiple orbital cycles, would be required.

According to the researchers, the Martian layers could be evidence of a shorter-term process that affects the deposition of ice and dust at the poles, perhaps similar to the way the El Nino Southern Oscillation produces intermittent changes in Pacific Ocean temperatures and rainfall.

Perron and Huybers do not rule out the possibility that the layers they observe are part of an orbital signature, and they note that new data from current and future Mars missions could reveal whether the layers on Mars are, or are not, like the ones buried in Earths oceans and Antarctic ice. (ANI)

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