Sky Treat: Blemish the Shuttle and Space Station

The space shuttle Atlantis and the International Space Station are individually flying around the Earth until Friday, and they can be seen as a couple of bright lights in the sky at assured times over the next few days.

Weather allowing, the orbiting objects should be evident to the naked eye all over the United States and Canada. It's a special chance to see the two largest man-made objects in the sky at once.

Atlantis undocked from the space station early Wednesday, ending a week-long stay to provide the settlement with spare parts. The shuttle is planned to land at Kennedy Space Center in Cape Canaveral, Fla. on Friday morning at 9:44 a.m. EST (1444 GMT).Numerous sites can tell you when the two spacecraft are able to be seen from your location between now and landing day:

• NASA's SkyWatch
• Spaceweather.com
  

Considering a satellite from Earth isn't that rare: The countless communications satellites flying around Earth regularly emerge at night as stars that look to be transiting across the heavens. But the shuttle and station are both larger than any other vehicle in orbit, and should become visible much brighter than the average satellite.

On a good night, the station move towards magnitude -5 in brightness, which equals the planet Venus and is more than 25 times brighter than Sirius, the brightest star in the night sky.