Sand dunes near
the north pole of Mars show their seasonal change in this image by the 2001
Mars Odyssey.
The
crescent shapes of the dunes could resemble migrating birds in flight against a
blue sky on Earth, or a finely woven net or mesh. They are part of a sea of
sand that scientists call an “erg.” Summer on Mars peels back the winter coat
of ice through sublimation to expose the reddish-brown material underneath.
Scientists
won’t have to be content with just admiring such dunes from afar much longer,
as the Phoenix Mars Lander readies
for landing on May 25. Odyssey will be among three Mars orbiters that turn
their sights from the planet to the spacecraft in order to track Phoenix’s descent.
— JPL-Caltech and SPACE.com Staff
Credit: NASA/JPL-Caltech/Arizona
State University
Return each weekday for a new SPACE.com Image of the Day.
| 
