Mars’ largest moon Phobos shows signs of being ripped apart by the extreme gravitational forces exerted on it by the Red Planet.
Researchers have revealed that the unusual
grooves covering Phobos’ surface, previously assumed to be scars from an ancient asteroid impact, are actually dust-filled canyons that are growing wider as the moon gets stretched out by gravitational forces. Phobos is around 17 miles across at its widest and orbits Mars at a distance of 3,728 miles, completing a full rotation three times every day. Unlike our Moon, Phobos’ orbit around Mars isn’t stable. The tiny satellite is trapped in a death spiral and is slowly falling towards the Martian surface at a rate of 1.8 metres every 100 years. But Phobos’ most unusual feature is arguably its mysterious stripy surface. Parallel grooves, or surface striations, cover the moon. The most widely accepted theory suggests that the striations formed when an asteroid slammed into Phobos at some point in the past, leaving behind a six-mile-wide crater, known as Stickney, in the moon’s flank.