Assuming the Space Shuttle Discovery undocks as scheduled from the International Space Station at 7:33 AM EDT tomorrow (i.e., Wednesday) morning, there will be an opportunity tomorrow night for folks in parts of the southeastern U.S. to see the Shuttle and ISS flying overhead side-by-side.

Here in Knoxville, the 9:04 PM EDT flyover is just 11 minutes after sunset, so I’m not sure how visible the spacecrafts — particularly the dimmer Shuttle — will be. Certainly, there won’t be much to see if you’re west of Knoxville; the sky will be too bright. But the further east you go, the darker the sky will be at the requisite time. Thus, both the Shuttle and ISS should be easily visible in places that are east of Knoxville and reasonably close to the black line below:

Along the Carolina and Georgia coasts, all across the Florida peninsula, and in the Bahamas, the view should be stunning, weather permitting. As I’ve said before: "Trust me: even if you’re not into dorky stuff like Iridium flares, this is well worth a trip outside at the proper time, if the sky is clear." The sight of "two distinct, bright dots, moving briskly across the evening sky in
tandem — two unmistakable beacons of the human presence in space" is "a really neat thing to see."

You can use Heavens-Above to check the specific viewing conditions for your location. If you’re in the U.S., just click here and enter the name of your city or town, then select it from the resulting list of locales. On the screen that follows, click on "10 day predictions for: ISS" and look for an evening flyover on June 11 (or for that matter, June 12 or 13). If you’re outside the U.S., select your country here and then follow the same steps.

It’s a shame the flyover is so close to sunset here in Knoxville, because from this location, the spacecrafts’ path takes them right past Mars, Saturn and the Moon: