Scientists at the U.S. space agency NASA say they have discovered evidence of carbon dioxide snowfalls on Mars.
The space agency data provided by its Mars Reconnaissance Orbiter provides evidence that the Red Planet has snow clouds made of frozen carbon dioxide, better known as "dry ice."
NASA says data from observations in Mars' south polar region during its 2006-2007 winter points to what would be the only known example of carbon dioxide snow falling in the solar system.
NASA study author Paul Hayne said in a statement Tuesday that the finding of snowfall could explain why Mars' south polar residual ice cap persists year-round.