A nice new satellite pic (actually a composite of images from NASA's Landsat) from the Earth Observatory.  The volcano, Tarso Toussidé, is located on Chad's Tibesti Mountain Range.  From the EO's site:

Looking like the result of a giant inkwell tipped on its side, Tarso Toussidé underwent a violent eruption in the recent geologic past, and the remains of that eruption have stained the ground black. The volcano ejected tephra, fragments of rock and volcanic glass, lava, and ash. Tephra does not last on the landscape as long as consolidated volcanic rocks such as tuff or lava, so the presence of tephra suggests fairly recent activity. In the middle of the field of dark tephra is Pic Toussidé, a lava dome poking out of the current caldera.

Volcanoes often sport multiple calderas, particularly as the primary site for eruptive activity shifts over time. East of Pic Topussidé are two calderas, the southern one bearing a white splotch roughly 2 kilometers long. This white color could result from salt. Water pooling in the caldera would not have an outlet, and as the water evaporated, minerals such as salt would be left behind.

Image courtesy Robert Simmon/Earth Observatory.

Also: NASA released some cool movies today of Saturn revolving in orbit with its moons. They're sharp enough to look like computer animation but are really compilations of images taken by Hubble over periods of several hours.