we are on the same wavelength [art]

we are on the same wavelength

we are on the same wavelength

Ten Things You Didn’t Know About the Milky Way Galaxy

Ten Things You Didn't Know About the Milky Way Galaxy

Ten Things You Didn't Know About the Milky Way Galaxy

You've lived here all your life, but how much do you really know about the Milky Way galaxy? You know it's a spiral, and that it's 100,000 light years across. But here are some things you probably don't know: 1) It's a barred spiral A lot of spirals galaxies have a weird feature: a rectangular block of stars at the center instead of a sphere, and the arms radiate away from the ends of the block. Astronomers call this block a bar, and we have one -- a big one, in fact, 27,000 light years end-to-end. 2) There's a supermassive black hole at the center Right at the core of the galaxy lies a supermassive black hole. We know it's there because of its effects; it causes stars near the center to orbit at fantastic speeds of thousands of kilometers per second. It is as massive as 4,000,000 suns. 3) It's a cannibal The Milky Way is currently eating several other, smaller galaxies. Eventually they'll merge with us completely. 4) We live in a nice neighborhood We're part of a small group of nearby galaxies, which also includes the Andromeda galaxy and the Triangulum galaxy. There are about three dozen galaxies in the group. 5) We're in the suburbs That small group is a far-flung part of the Virgo Cluster, a huge collection of about 2000 galaxies. The total mass of the cluster may a quadrillion times the mass of the Sun. 6) You can only see 0.000003 percent of it The Milky Way has two hundred billion stars in it; you can only see a tiny fraction of them in the night sky. 7) 90 percent of it is invisible Most of the galaxy is made of a mysterious substance called dark matter. No one is sure yet exactly what that is. 8) The spiral arms are an illusion We see the arms because the light is better there, not because that's where all the stars are. The light is caused by massive hot stars illuminating surrounding gas clouds. 9) It's seriously warped The disk is of the Milky Way is bent, probably due to the gravitational influence of a pair of orbiting satellite galaxies. One side of the disk is bent up, and the other down. 10) We're going to get to know the Andromeda galaxy a lot better The Andromeda Galaxy and the Milky Way are approaching each other at 200 kilometers per second. In a few billion years, they will collide and merge. Sources: Bad Astronomy March 12, 2008