Mars' moon Phobos is a strange, cratered, misshaped moon -- and it's pulling itself to pieces from the inside out.
Because Phobos is so close to the Martian surface, it's subject to a much stronger than usual gravitational pull. The result of that pull can be seen up close in what researchers are calling "stretch marks" covering the moon:
NASA estimates that Phobos will have completely broken up within 30-50 million years.
Images: NASA's Goddard Space Flight Center and ESA/DLR/FU Berlin/G. Neukum