The grooved appearance of Phobos probably caused by the rolling of rocks

One of the most interesting moons in orbit around the planet in our solar system is Phobos, the moon of Mars. One of the key aspects of this moon is its strange shape and its unique grooves that cross the moon's surface in roughly the same direction. Brown University has developed computer models to determine the exact cause of grooves on the surface of the moon.

The computer sims examined the movement of the debris from Stickney Crater, which is the massive crater at the end of the oblong surface of the moon. Ken Ramsley, a researcher at Brown University, explains precisely how these grooves were formed for 40 years. One theory had to do with a huge impact on Mars spilling debris into Phobos.

Another theory is that the gravity of Mars tears the moon and that the grooves are signs of structural failure. Other scientists believe that the grooves are related to the impact of the Stickney crater. This theory posits that Stickney's bouncy, slippery and rolling blocks carved the grooves of the moon.

Phobos is a small moon located 27 km from the widest point. Stickney Crater is gigantic compared to 9 km in diameter. The argument against this theory is that some of the Phobos grooves do not align radially with the Stickney Crater as one might expect.

Another argument against this theory is that there appear to be grooves created at two different times, suggesting that they could have been there before crater formation. The computer models created by the researchers showed that the rolling rock theory could be correct because it showed grooves that looked a lot like the surface of Phobos. The simulation also gave an idea of ​​what could have caused the grooves aligned differently. Basically, some rocks seemed to have circled the moon because of the low gravity and their small size.