A Moon Falling Apart: Grooves on Phobos Are a Sign of its Eventual Catastrophic Fate

The unusual grooves on Phobos’ surface, such as those on the left side of this image, are now thought to be caused by tidal stress. The large crater Stickney is in the upper portion of the image. Image Credit: NASA/JPL-Caltech/University of Arizona

Phobos is the largest of Mars’ two tiny moons, but 50 million […]