Sand is blowing in the wind on the surface of Mars _ at least in some places.
NASA on Thursday released images documenting dozens of spots on the red planet where sand dunes shifted several yards. Scientists had suspected this was occurring but thought it was limited to a few locations.
The latest images were taken by the Mars Reconnaissance Orbiter, which has been photographing the Martian surface since 2005.
Dust is constantly being blown around on Mars, but sand grains are tougher to move. In a study published online in the journal Geology, scientists surmised that the planet has stronger winds than expected in order to move the sand.