Test
Do you ever wonder about the things in the sky -- the Sun, the moon, and the stars? People have been watching the sky for a long time, trying to figure out what is out there. We keep coming up with new ways to learn more about outer space.
We live on Earth. Earth is a planet (like a very big ball) that goes around and around the Sun. A lot of other objects go around the Sun, too -- together, all these things are a system. The Latin word for the sun is Sol, so we call this system the Solar System.
A long time ago, people did not realize that all these things go around the sun. They only knew what they could see with their own eyes. They figured out that planets go around the Sun[1]. Then, about 300 years ago, Galileo looked at the sky with a telescope[2][3]. Soon, more people used telescopes to watch the sky carefully. They learned more about how the moon and planets move.
References
- ⇧http://www-spof.gsfc.nasa.gov/stargaze/Ssolsys.htm#q21
- ⇧http://www-spof.gsfc.nasa.gov/stargaze/Ssolsys.htm#galileo
- ⇧{{Book reference|Author=Drake, Stillman (translator)
|Year=1957|Publisher=Anchor, NY|