Tuesday, July 21, 2009

George’s Secret Key to the Universe Week 8

WOW! Eric is in big trouble – black holes are amazing and very scary… and now Eric has fallen into one! Most people think that a black hole is a hole, but actually it is an object just like a star or a planet. But, a black hole has so much gravity that even light cannot move away fast enough to escape, which makes black holes invisible to our eyes. You see, in space, the more mass something has, the more gravity it creates. So the sun has more gravity than Earth and Earth has more gravity than the moon because the sun is the biggest and the moon is the smallest. Most black holes come from supernova, the explosion of a super massive star. Then all that mass condenses down into a smaller, but extremely massive object with a HUGE amount of gravity – which we all call a black hole.

Before the black hole began to suck up Eric and George, they were talking about Eric’s quest to find a new planet like Earth – one where humans could live. Think for a second about what that would have to be like. It would have to have similar gravity, similar temperatures, and similar chemicals in the air and on the surface. Finding another planet so similar to ours is a very big challenge, but lots of people at NASA are working hard to do so.

I can hardly wait to read what happens next!

Jill