The rock that orbits Mars is Phobos, one of its two moons. Taken at a distance of 6,800 km ( 4,200 mi), the picture below was captured by HiRISE (High Resolution Imaging Science Experiment) aboard NASA’s Mars Reconnaissance Orbiter. Phobos

Check out the large impact crater on the right side of Phobos. There are striations emanating from the edge of the crater moving from the lower bottom right to the upper left of the face of the moon. It looks like flames left a mark after the impact. Probably not flames of course, but it is mind boggling to consider what might have caused these striations. Possibly ejected debris from an impact?

The crater has a name, naturally. Named Stickney, it has a diameter of 9 km ( 5.6 mi). Scientists from the European Space Agency’s Mars Express believe these marks occurred from impacts on Mars which ejected debris high enough up from the planet to have impacted Phobos. Those were probably some massive hits that Mars took, but Earth likely experienced the same thing.Mimas

Inside the crater Stickney can be seen a series of textures which are landslides formed when material fell into the crater. Phobos gravity is less than 1/1000 of Earth’s. They look like someone used a large spoon and scooped material out of the wall of the crater.

Stickney reminds me of the crater on Saturn’s moon, Mimas. The crater is named Herschel and defines Mimas, shown in the picture at right.

Actually, the two moons of Mars really are essentially rocks. They are believed to be stray asteroids that wandered in too close to Mars and were captured by the planet’s gravity.