Phobos ahoy!

The entire universe in blog form
March 2 2010 2:15 PM

Phobos ahoy!

Over the next few weeks, the European probe Mars Express will be making a series of close passes to the Martian moon Phobos, a wrecked potato that has had an extensively battered history. In January, ME got this shot (among others):

marsexpress_phobos

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You can see that this little moon has been kicked around quite a bit. Those parallel grooves are still a bit of a mystery; they are most likely cracks that formed when Phobos got whacked, creating the 10-km-wide crater Stickney on one end, but that matter is not 100% settled. Maybe these new observations will help end the debate. [UPDATE: Commenter Big Bob points out that the cracks are most likely not due to the Stickney impact! I haven't kept up on my Phobos groovy research, obviously. Also, in the next bit I say more images are coming, but in fact this close passage of Phobos will not yield very high-res pictures, because this flyby is to measure the gravity field around Mars, and the other instruments -- including the cameras -- must be turned off. Oh well.]

And as nice as this image is, we'll be getting lots better ones soon! So this is a heads-up: closest approach is on March 3, so stayed tuned for more pictures. I'll post 'em as I see 'em.

Phil Plait writes Slate’s Bad Astronomy blog and is an astronomer, public speaker, science evangelizer, and author of Death from the Skies!