The real tetrahedrons of Mars

A Piece of Mars: The real tetrahedrons of Mars are dunes, built by winds blowing sand from more than one direction. This 0.5×0.5 km (0.31×0.31 mi) area shows a dune formed from two winds that are about 90 degrees apart: one blowing from the bottom and one blowing from the right. This makes the dune

The thinnest landslides

A Piece of Mars: In the dustiest regions of Mars, steep slopes occasionally produce very thin avalanches of dust, revealing a darker surface under the top layer of dust. This shows one that is 610 m (0.38 mi) long, running from its tiny point of initiation near the top of the slope down to the