It seems like all eyes are on Mars lately. But several Earth-orbiting satellites continue to photograph this planet, too. Sometimes it's hard to tell which world we're looking at.

This image shows a region of southern Iran, where a collision between the Asian landmass and the Arabian platform has folded rocks and pushed up the rugged Zagros Mountains. In places, underlying deposits of salt have ascended in fluid-like plumes, NASA scientists explained.

Some of these plumes have pushed through the rock above, like toothpaste from a tube, and they are now visible as darkish irregular patches. This image shows a few of more than 200 similar features -- called diapirs, or salt plugs -- that are scattered about this part of the Zagros Mountains.

Gravity has caused the salt to flow like glaciers into adjacent valleys. The resulting tongue-shaped bodies have repeating bow-shaped ridges separated by crevasse-like gullies and with steep sides and fronts.

The darker tones are due to clays brought up with the salt, as well as the probable accumulation of airborne dust. The data for this image, released this week, was gathered in August 2001.

Credit: NASA/GSFC/MITI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team