Round and Round They Go
Do you ever say the sun is “coming up”? It really does seem like the sun is traveling around our earth. The Greek astronomer, Ptolemy, thought the same thing almost 2,000 years ago; many centuries later, a stargazer named Copernicus claimed that our planet really circled or made an orbit around the sun! Each month you can see the shape of the moon change, but around 400 hundred years ago, a famous astronomer called Galileo was watching the changing shape of the planet Venus! This proved to him that it did revolve around the sun. You can go on the Internet and find pictures of Venus and learn when it would be the best time to view this phenomenon. Sometimes you can see it by using only a pair of binoculars. You probably already knew that the planets circle around the sun and that many of them have moons and rings that circle around them. But, did you know that our sun circles around the center of our galaxy? With so many things moving around here on Earth and out in the universe it is amazing so few things collide.
A galaxy is a group of stars out in space. There are numerous galaxies in the universe. The galaxy we live in is a spiral galaxy. Galaxies can come in different shapes and sizes.
JUST for FUN
The Revolving Game
To do this activity you will need several children to be planets and moons. One person can be Earth, another will be the moon, another will be the sun, and others will be the other planets. Once you have everyone in place, start revolving. (The sun stands in the center, the planets spin and revolve around the sun, and any planets' moons revolve around them.) Remember that Earth will be spinning at the same time it is circling the sun. Now try trading places and do it again.