Th red planet's hot again, cold again history: Explaining persistent hydrogen in Mars' atmosphere
The fact that the cold, dry Mars of today had flowing rivers and lakes several billion years ago has puzzled scientists for ...
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Newly discovered super-Earth orbits in and out of its star's habitable zone. Could life survive its extreme climate?
A super-Earth planet that dips in and out of its star's habitable zone has been discovered just 19.7 light-years away.