Long ago, something struck Phobos and almost shattered the tiny moon. The scar of that impact, 9km-wide Stickney crater, is located at the top of the image. Color filters in MRO's camera reveal a blue splash of material around Stickney's rim. What is it? No one knows. Equally striking are Phobos' many long grooves and crater chains. Although these seem to radiate from Stickney, recent studies show that most are not related to the crater. Instead they come from the planet below; when asteroids hit Mars, debris flies up and scores Phobos. The grooves seem to emerge from Stickney only because the crater faces Mars.