New Mars rock hints at short-lived lakes New Scientist

The Mars rover Opportunity has discovered hints of a type of rock never before seen on the planet. Its presence would mean that any watery periods in Mars’ past were cold and short-lived. Opportunity has been perched on the rim of a 130-metre wide crater dubbed Endurance since early May. It has been using its remote sensing instruments to study the rocks exposed in the steep sides of the crater.