Water ice found at the south pole
It was previously known that Mars has ice situated at its poles. This is not to the same extent as Earth, as Mars’ polar ice is much thinner and more seasonally variable.
More surprising, Mars Express’ Observatoire pour la Minéralogie, l'Eau, les Glaces et l'Activité (OMEGA) instrument revealed that water ice, as well as carbon dioxide ice, is present at both the north and south poles.
OMEGA measured the amount of sunlight and heat reflected from the poles to confirm this result. In the case of the south pole, scientists were also surprised to see vast amounts of perennial water ice encasing it.
The steep slopes, known as ‘scarps’, are made almost entirely of water ice