Massive Ancient Collision ‘Puffed and Fractured’ the Milky Way

True Twisted shape of Milky Way Galaxy


“While there have been many dwarf satellites falling onto the Milky Way over its life, this was the largest of them all,” said Sergey Koposov of Carnegie Mellon University, about the collision 10 billion years ago with the massive Gaia Sausage satellite galaxy, whose total mass in gas, stars and dark matter was more than 10 billion times the mass of our Sun, which lies in the center of this enormous cloud of stars.