Martian moon’s grooves are early signs of a long, slow crumble into oblivion
OXON HILL, Md. — Mars’ moon Phobos is stressed and starting to crack under pressure. A network of grooves encircling the moon are early signs that the Red Planet’s gravity is splintering Phobos, Terry Hurford reported November 10 at a meeting of the American Astronomical Society’s Division for Planetary Sciences.
Phobos, unlike its sibling satellite Deimos, is slowly spiraling toward Mars. “As [Phobos] gets closer… it gets pulled out into a football shape,” says Hurford, a planetary scientist at the NASA Goddard Space Flight Center in Greenbelt, Md. “The changing shape causes stresses that we think form the grooves.” Sometime in the next 50 million years, the stress will become too much and the moon will break apart.
The grooves were first seen by the Viking landers in 1976, and some researchers proposed stress fractures as a cause. But scientists also