Interesting Facts about Galaxies

1. (GALAXY SIZE) The average Galaxy has 100-200 billion Stars (most similar to our sun) encircling the center. Note, that a very new study, has been proving that something called supermassive black holes exist in the center of nearly all galaxies. Including in our own.

2. (GALAXY SPEED) When growing up as a child, all of mankind has been wanting to know hard, factual, details about space which have only recently been calculated, and proven true. Details like, "What is the speed of the arm of a galaxy that is traveling around its center?" I have always wanted to know numbers like this because, since we are within the arm of such a galaxy, such numbers would mean this is the speed at which our own bodies are actually flying through real space. That speed, is an amazing number. As you will see below, the arm of a galaxy such as ours, must turn fairly quickly to go full circle. The speed is 140 miles a second .

In the time it takes you to finish this sentence, you will have been carried along by the sun and the earth, moved through actual raw space of 750 miles ! In the time it takes you to ponder that, you will have moved another 700 miles or so through real space. How nice to travel so fast through raw space every second of our life, without colliding into anything with our physical bodies ( We do run into space rocks along the way, but they almost always get burned up by the atmosphere of the earth, smashed like a bug running into the windshield of a fast moving car!)
Back on earth, if somehow you could stop, say, a rock resting nearby you on the ground, and keep it from moving along with you and the planet through space, you would then be able to watch it stay put, as you keep moving in the arm of the galaxy through space. That rock, while remaining suspended in space, would be 140 miles away after one second. We do not have jets that travel that fast away from anything. (I have not calculated this number.. but one second of a jet at its fastest is probably traveling.. well let me look this up.

(To do this, first I would go to this link for further documentation, and find out the speed a jet rocket plane travels in one minute or hour, using The Physics Factbook and then do the math from their info.) After looking, in fact, the fastest jet planes only travel in speeds of one mile per second.. not 150 miles per second !

Okay.. so now we know the speed of the arm of the galaxy... 140 miles per second, and remember, that is about 140 times faster than the jets we think of today! In fact, if you think about how fast a jet travels across the sky, after a minute or two it is out of sight, right? Well, if it was traveling 140 times faster or 140 miles a second, then it would go across the sky and be out of sight in less than one second!

http://www.motodom.com/Galaxy.htm