Scientists may have solved the mystery of Martian moon markings

The question of how the Martian moon Phobos got the strange groove patterns crisscrossing its surface has captured imaginations for years.

Using advanced computer modeling techniques, scientists from Brown University believe they've come up with an answer: rolling boulders, which were the result of an asteroid impact 150 million years ago, causing the moon's giant Stickney Crater in the process.