Ever stopped, looked up and wondered about that bright light drifting across the night sky? Don’t worry.

Tuesday, December 18, 2001

Ever stopped, looked up and wondered about that bright light drifting across the night sky? Don’t worry. It’s not a UFO. It’s probably the space shuttle, International Space Station or some other satellite in Earth’s orbit.

If conditions are right, you can see satellites and other spacecraft clearly from the ground, which appear as small, steady, extremely fast-moving points of light, the National Aeronautics and Space Administration (NASA) says.

The International Space Station, or ISS, is now one of the most visible objects in the sky – as bright or brighter than most stars. Most sightings follow a west-to-east path and the spacecraft appears over the western horizon and disappears over the eastern in a matter of a few minutes.

For example, the next best time – according to NASA’s and other space-watchers’ estimates – to see the space station will be early Friday evening.

The space station should rise above the horizon about 6:41 p.m., moving from northwest to east-southeast.

It should peak about 83 degrees above the horizon, almost directly overhead, about 6:44 p.m. The satellite should pass into Earth’s shadow less than a minute later, and disappear.

If you miss it Friday, the same show begins Saturday evening about 5:43 p.m., although the satellite does not pass as high overhead as on Friday.

The space station and other satellites drift across the early evening sky – reflecting the setting sunlight – every few days, depending on its orbit above the Earth.

In fact, the space station orbits at more than 380 km above the Earth, passing by almost 16 times per day.

Those times it passes over a certain city can change slightly from day to day depending on the stability of the orbit and other factors, so check with NASA or private satellite spotting groups often.

One of the best ways to check, and to schedule your own observing times, is with NASA’s SkyWatch program – http://spaceflight.nasa.gov then click on "Realtime Data" and the SkyWatch start button, or scroll down the screen to the SkyWatch link.

SkyWatch is an Internet-based computer program designed to tell you when to go outside and spot for a satellite. (Try the space station first since it’s brightest.)

Follow the directions on which browser is best suited to view the SkyWatch program. Then, select the satellite and select the city from which you’re viewing. The computer does the rest.

Another less tricky way, to find out when the space station will fly overhead is to use a private Web site to find out. Many amateur space watchers compute times and post them so you can see, too.

Try pointing your Internet browser to http://www.heavens-above.com – a site that lists times that dozens of satellites pass overhead. Either register or anonymously select your city (it lists Ironton and others in Lawrence County) and click the satellite you want to watch. This site even produces sky charts for easier spotting.

Exploring both NASA’s Web site and others can unlock a wealth of information about the thousands of satellites orbiting overhead, and lead to hours of fascinating sky watching.