Mars, Like Earth, Has Cyclical Ice Ages, Study Says

In this article, scientists discuss the history of Mar's ice ages and the new theory that surround them. Within the last 5 million years, Mars has undergone 40 different ice ages. As these occur, they send the sheets of ice down to the equator and than they melt back upwards. The reasons for the variation in ice ages has to do with the amount of sunlight reaching the surface of the planet. Evidence of ice has been found very far from the poles of the planet, and originally it was thought that this ice formed following snowfall on the planet around 5 million years ago. Now scientists believe that the ice was formed more recently than originally though. Scientists now believe that most of Mar's ice has been formed by vapor diffusion—the seeping of gas directly into underground pockets during cold periods. This could completely alter the history originally thought for the planet.

The reason scientists believe there are so many different ice ages has to do with the wobbly theory, which suggests that because the planet has no moon to stabilize it, it is subject to varying degrees of wobble from its normal position at 25 degrees. As the planet wobbles, the amount of sunlight reaching the surface of the planet varies and the ice sheets move towards the equator or the poles.