Think about this for a moment -- we're seeing a different moon from the surface of a different world. And this moon is weird not just for its lumpiness, but also because it orbits so close to Mars that it outpaces Mars' rotation. That means it rises in the west and sets in the east, more than twice every Martian day. Completely alien. And awesome, in the literal sense of the world.

I would not have noticed this image were it not for the ever-watchful members of unmannedspaceflight.com (user "fredk" this time). I'm so grateful for that community. We're running a fundraiser right now to support our hosting costs -- if you, too, value the beautiful images and constant attentiveness of this community of volunteers and amateurs, please consider making a donation to support it.

* NOTE: I originally had the wrong time of day for this image, but as a commenter pointed out, it was taken at 13:27 UT on September 21, 2012, which corresponds to 17:27 at Curiosity's location on Mars. Sunset occurred at 15:21 that day. --ESL