Watching Satellites

Did you know that you can see satellites with just your eyes? Incredible as it may seem this is one of the things that really got me interested in looking skyward. I was 20 years old when I realized that I saw my first satellite. After that I looked for them frequently. They look, to me, just like stars only they are moving ... some very quickly.

The next memorable experience of satellite watching was when my son was about 12. I told him we could see satellites just like on "Rocket Boys" and that got him excited. Within about 20 minutes he saw his first satellite flying over. Unlike me he's still not very interested in star watching or space exploration.

Do you want to see a satellite? It's really quite simple. I've noticed that the best time to view is either about 30 minutes after the sun sets or about 30 minutes before the sun rises. Obviously you need to have clear skies because satellites circle the earth high above the clouds. Most are orbiting at about 500 miles above the surface of the planet.

There are several internet sites that have information about spotting satellites. Here are some including my favorite one other than Starry Night software.

J-Track Satellite Tracking from NASAis my favorite free to use tacking software. It's pretty simple to use and gives you the exact time to walk out and look up. As long as you know where you live (go to this link and type in your address) you can be sitting inside playing a video game or reading about space exploration and walk out just in time to look up and see the satellite pass over.

Heavens Above is a site that I've used often but it provides great information about satellites and their locations. This site is more text based and a little harder to use than J-Track (above) but they have recently added more active graphics.

Most satellites are smaller than your family car. Some, such as the International Space Station or the one of the NASA Space Shuttles are much larger. Some satellites are orbiting in what is called a Geostationary Operational Environmental Satellite(GOES) which means it appears to you, if you are standing on the ground looking up, to be stationary. They orbit the earth high above and at a speed matching the rotation speed of the planet. They are also harder to see because they orbit the earth at about 22,000 miles high. The Shuttles orbit at about 140 miles and is very easy to spot when in orbit.

Polar Orbiting Earth Satellites (POES) go around the earth at about 1000 miles and move very quickly, about 1000 miles per hour. With any satellite the orbiting speed depends on the height of the orbit. The higher the orbit the slower it can move in relation to the surface.

The earth rotates from east to west at 1041 miles per hour. If you want to match the speed of the rotation of the earth and you are high above it you need to do some math to determine your "space speed". Physics are required and an understanding of centripetal force is key to determining the correct speed of orbit. That's a little too advance for this article but if you want a sneak preview just look at this link.

To end this article I recommend you plan on spending some time laying on your back or in a reclining chair on a clear night just after sunset and looking for "stars" that are moving. You'll know when you find a satellite. They don't flash, the don't change speed or direction and they move a little faster than most jetliners. Let me know what you see, we're all interested!