Mars South Polar “Lakes” Are Actually Clay

A new paper provides multiple lines of evidence that show the cause of the bright radar reflections under Mars’ south polar ice cap is actually a clay called smectite.

IMAGE: This image taken by NASA’s Mars Reconnaissance Orbiter shows ice sheets at Mars’ south pole. The spacecraft detected clays nearby this ice; scientists have proposed such clays are the source of radar reflections that have been previously interpreted as liquid water. CREDIT: NASA/JPL-Caltech/University of Arizona/JHU

A few weeks ago, I brought you the story that bright radar reflections from under Mars’ south polar ice caps were…