The dominant feature on the surface of Mars’ largest satellite, Phobos, is Stickney — a 9-kilometre-wide mega crater that spans nearly half the moon. The crater lends Phobos a physical resemblance to the planet-destroying Death Star in the film “Star Wars.” But over the decades, understanding the formation of such a massive crater has proven elusive for researchers.
Lunar swirls have been the source of debate for years. The twisting, swirling streaks of bright soil stretch, in some cases, for thousands of miles across the Moon’s surface. Brown University researchers have produced new evidence that they were created by several comet collisions over the last 100 million years.