Mars was ‘always cold and frozen’ New Scientist

The idea that Mars was once a warm place, awash with oceans that could harboured early life has taken a knock – new data suggests it was always cold, frozen and probably lifeless. A survey of the Red Planet’s surface has revealed only traces of carbonates, minerals that should have formed in abundant quantities if Mars once had expansive seas. On Earth, the mineral is found in limestone and chalk deposits around the world.