ESA’s great Phobos animation – showing a 360-degree view of Phobos – is today’s APOD! What a great way to celebrate the holiday (and MEX’s 10th anniversary of arrival at Mars)! Better yet: Mars Express is lined up to make the closest-ever flyby of Phobos on 29 December, just 45 km from the surface. (There won’t be any images, but we’ll keep you updated here in the blog.)

What does the Martian moon Phobos look like? To better visualize this unusual object, images from ESA’s Mars Express orbiter have been combined into a virtual rotation movie. The rotation is actually a digital illusion – tidally-locked Phobos always keeps the same face toward its home planet, as does Earth’s moon. The above video highlights Phobos’ chunky shape and an unusually dark surface covered with craters and grooves. What lies beneath the surface is a topic of research since the moon is not dense enough to be filled with solid rock. Phobos is losing about of centimeter of altitude a year and is expected to break up and crash onto Mars within the next 50 million years. To better understand this unusual world, Mars Express is on course to make the closest flyby ever on Sunday.