Creekside Astronomy: Satellites
How do satellites stay in orbit?
How do they communicate information?
Here are some ways we explored satellites recently.
Satellites in Orbit. To demonstrate how a satellite stays in orbit, rather than zinging off into outer space or dropping to Earth, we used a marble and a round mirror. You could also use a plate or pot lid, anything that’s round and with a lip or edge to it. I explained that the marble represents the satellite and the mirror is Earth. The kids had fun spinning the marble around and keeping it in orbit. It took a few tries not to spin it too fast (causing the marble to fly off the mirror) or too slow (causing it to stop or go off course).
We talked about how moons are satellites, too, and they are held in orbit the same way as artificial satellites, by gravity. We did a similar experiment when we learned about the moon a few weeks ago.
Then we put the marble in a jar, placed the lid on top and tried different ways of spinning the marble around the edges of the jar. We tried different motions: spinning it left to right with the jar upright, spinning it towards our bodies and away from our bodies with jar on its side. This experiment was inspired by Janice VanCleave’s 200 Gooey, Slippery, Slimy, Weird and Fun Experiments. It demonstrates how the concepts of gravity and centripetal force, or force toward the center, work together to keep the satellite in orbit. I talked about this with my 7 year old but my 5 and 3 year olds simply had fun spinning the marble around and learning the new word, “satellite”. Both my 5 and 7 year olds were curious to learn that our t.v. programs and our cellular phone calls involved satellites.
Satellites Communicate. To demonstrate how satellites communicate using their mirrored panels to bounce radio waves, we used used a flashlight and our trusty mirror again. We put the mirror just outside of one room and bounced the light of the flashlight off of the mirror into the other room. I had the kids take turns. One used the flashlight, the others went into the other room and sat where they could not see the flashlight holder. They could, however, see the light as it bounced onto the floor, the wall and various objects in the room. This experiment also came from Janice VanCleave’s book.
Make a Lego Satellite Next I tasked Firefly, my 7 year old, with building a Satellite out of Legos after we looked at pictures of them in our Usborne Book of Astronomy and Space. He returned from Lego Building Headquarters (also known as his bedroom) with his creation.
- A great graphic on how satellite t.v. works.
- Visible Earth, a NASA image gallery of satellite images.
- NASA kids club, Wow! What a View, views of Earth from space. Love this interactive site for younger kids. Lots more great things at this site.
Satellite image courtesy of Microsoft clip-art.