PARIS, Sept 25: Mars undergoes periodic wobbles in its spin and variations in its orbit that, like the Earth, may cause it to endure prolonged Ice Ages or other climate shifts, scientists say.

The evidence comes from the latest pictures of the Red Planet’s northern polar ice cap, a thick dome of what is apparently water ice mixed with dust, and which is up to 2.5 kilometres thick.

The extraordinarily precise images captured by the US Mars Global Surveyor orbiter show a spiral pattern whose accumulated icy layers and deep troughs are the result of scouring by fierce winds and evaporation caused by exposure to the distant Sun.

A team led by Jacques Laskar at France’s National Centre for Scientific Research (CNRS) in Paris calculates that the cap is accumulating at the rate of about 0.05 centimetres annually.—AFP