Some of the mysterious grooves on the surface of Mars' Moon Phobos are the result of debris ejected by impacts eventually falling back onto the surface to form linear chains of craters, according to a new study. In this spacecraft image of Phobos, red arrows indicate a chain of small craters whose origin researchers  were able to trace back to a primary impact at the large crater known as Grildrig  [Credit: ESA/Mars Express,...

[[ This is a content summary only. Visit my website for full links, other content, and more! ]]