Space Station and Shuttle Visible Together in Night Sky

Newsblurb: All of you amateur astronomers here might want to drag out those telescopes and binoculars tonight and tomorrow night.

MISSION ATLANTIS

Joe Rao
SPACE.com Skywatching Columnist
SPACE.com Mon Jun 18, 4:00 PM ET

With the Space Shuttle Atlantis scheduled to undock from the International Space Station, on Tuesday, skywatchers across much of the United States and southern Canada are in for a real treat on Tuesday and Wednesday evenings.

Should weather conditions permit to offer clear skies, there will be a few opportunities to see both the Atlantis orbiter and the ISS flying across the sky from many locations.

The sight should easily be visible to anyone, even from brightly-lit cities.

The appearance of either the Space Shuttle or the Space Station moving across the sky is not in itself unusual. On any clear evening within a couple of hours of local sunset and with no optical aid, you can usually spot several orbiting Earth satellites creeping across the sky like moving stars. Satellites become visible only when they are in sunlight and the observer is in deep twilight or darkness. This usually means shortly after dusk or before dawn.

What makes the prospective upcoming passages so interesting is that you'll be able to see the two largest orbiting space vehicles in the sky at the same time.

What to expect

Both vehicles will be traveling across North America on northwest-to-southeast trajectories.

Appearing as a pair of very "bright 'stars," the ISS should appear as the somewhat brighter object and will appear to be trailing Shuttle Atlantis as they move across the sky. A large telescope would be needed to make out details of the sprawling station. Traveling in their respective orbits at approximately 18,000 mph (29,000 kilometers per hour), both should be visible from about one to four minutes (depending on the particular viewing pass) as they glide with a steady speed across the sky.