This past week in science class we learned a lot about space. Our Solar System, called Sol, is part of the our galaxy called the Milky Way, and the Milky Way is part of a bunch of galaxies which form our local cluster, and our local cluster is part of a bunch of clusters that form our local super cluster, and it goes on and on and on and on and on and on some more, a few more ons, several more ons, and on. So, Earth is pretty darn small when you put it in perspective! It's just too mind-boggling! If I think about it any more my brain's going to explode, and that won't be pretty because it'll make a big gooey mess on the floor. Okay my brain didn't explode so now I'll tell you about astronomical units, or au's. Au's are a unit of measurement that astronomers developed to help them tell the planets' distance from the sun. One au = distance from earth to sun. So, earth is one au, Neptune is 30 au's, Jupiter is 5.2 au's, etc. Now, lets talk a little about Earth. How did people know the Earth was round? Well, there are several different ways, but I'll tell you a very simple way. First of all, CHRISTOPHER COLUMBUS DID NOT DICOVER THE EARTH WAS ROUND=http://=http://=http://! I KNOW, ITS HARD TO BELIEVE BUT HE WAS FULL OF.... OF..... OF.... WELL HE WAS WRONG!!! People first knew the earth was round when watching ships sail out to sea. The would see as the ships slowly disappeared, the bottom of the ship going first and the mast last. Well, they figured out that they were watching as the ships went over the curve of the earth. Now, would you believe that a simple librarian figured out almost the exact size of the earth in B.C. Times?=http://! Well he did, and here's how: One day, a dude called Erastothenes walked down to the localwell. He noticed how the sun shone straight down into the well. Erastothenes then walked to a nearby town and looked into the well there. The sunlight didn't go straight down, it hit the side of the well! He now knew the earth was round. Next, he hired a guy to count the steps in between the two towns, and figured out some mathematical equations (probably involving pi), and got a very close number to the circumference of the earth. Wow! He's a nerd! That's just a small snippet of what we learned this week.