Posted by tourdemars to Mars Express at March 17, 2004 11:17 PM

Thanks to ESA’s Mars Express, we now know that Mars has vast fields of perennial water ice, stretching out from the south pole of the Red Planet. Planetary scientists have discovered that the south polar region of Mars can be split into three separate parts. Part one is the bright polar cap itself, a mixture of 85% highly reflective carbon dioxide ice and 15% water ice. The second part comprises steep slopes known as ‘scarps’, made almost entirely of water ice, that fall away from the polar cap to the surrounding plains. The third part was unexpected and encompasses the vast permafrost fields that stretch for tens of kilometres away from the scarps.