When Galaxies Collide

Astronomers have discovered two supermassive black holes at the core of a neighboring galaxy, but isn’t it just one supermassive back hole per galaxy? Not if two galaxies collide. Scientists are looking for shock waves or other evidence of a collision, but they are having trouble seeing signs that a collision actually occurred. The galaxy is 160 million light years away, which also means scientists are looking at a snap shot of 160 million years ago. It is being seen as it appeared back then, but we can’t see what it looks like now.  Coming a little closer to home, 25 million light years away, a star has gone Nova in the pinwheel galaxy. This is the closest Supernova to us that has been discovered since 1972. All this and more on this week’s Sky Talk.[audio: st20110905.mp3]