By Sid Perkins
Scientists scanning satellite images of the southern Sahara have detected trails left on the landscape by the whirlwinds commonly known as dust devils, the first such observations made from Earth orbit.
Cameras on several spacecraft that have landed on Mars have spotted such whirlwinds, and some images of the Red Planet from orbit show shadows cast by dust-filled funnel clouds, says Angelo Pio Rossi of the International Research School of Planetary Sciences in Pescara, Italy.