Ice belt 'encircled Mars equator'

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Europe's Mars Express probe may have found evidence for a band of ice that once spanned the Martian equator... They found that when Mars' tilt changed to an obliquity of about 35 degrees around five million years ago, moisture trapped at the North and South Poles may have been re-deposited in equatorial regions as snow. It is also possible that water trapped in the Martian tropics since ancient Noachian times was mobilised around five million years ago. Eventually, the poles may have got smaller and a thick belt of ice formed around the tropics... He added it was possible the ice could have got as thick as several hundred metres at high altitudes.