THE END OF THE MILKY WAY

摘要

For a tiny smear of light drifting in a sea of darkness, the Milky Way seems stable enough, and indeed it has been around almost as long as the universe itself. But just as gravity created the galaxy we call home, so it has sealed its fate: a slow-dance death spiral with the nearby Andromeda galaxy. Andromeda, also known as the spiral galaxy M31, is heading straight for us at about 360 kilometres per hour. The good news is that, being more than 2.5 million light years away, it won't collide with the Milky Way for another 4 billion years.