Japan’s doomed Hitomi observatory peeled back a veil on the inner workings of the Perseus cluster of galaxies before the satellite spun out of control earlier this year, revealing in unprecedented detail how gas heated to millions of degrees behaves around an unseen supermassive black hole, scientists said.
Where did the two natural satellites of Mars, Phobos and Deimos, come from? For a long time, their shape suggested that they were captured asteroids. However, the shape and course of their orbits contradict this hypothesis. Two independent and complementary studies now provide an answer: these satellites formed from the debris of a gigantic collision between Mars and a protoplanet one-third its size.