Posted by jburk to Planetology at January 19, 2006 07:53 PM

Large areas of the Red Planet were once turned white by heavy snowfalls that were common on Mars several million years ago, scientists say. A new model of the ancient Martian climate has revealed that the glacial deposits of the planet’s tropics were laid down by snow carried to equatorial regions by monsoon winds. The findings, published today in Science, resolve the mystery about the source of the rocks and debris at the foot of Mars’s tropical mountains and volcanoes spotted by Nasa’s Viking mission in 1976.