Mars weather threatens rovers
Okay, so it's a long way from Maryland. But the weather on Mars is pretty interesting, and we sometimes have better imagery to look at. In this case, it's raging dust storm, and it threatens to 
obscure the sunlight long enough to rob NASA's twin rovers, Spirit and Opportunity, of their solar electric power.
That elecricity is vital to keeping the rovers' batteries charged and their innards warm and functioning. Deprived of sunlight long enough, and the two robots, now in the middle of their fourth year on the Martian surface, will die. Read more about it here.
Here are a pair of images from a Mars orbiter showing how the global dust storm has obscured the surface.
And here is a satellite shot of a dust storm on Earth, over Pakistan and Afghanistan..
