The International Space Station is visible every couple of days as it passes overhead. At its best it looks like a bright star, crossing overhead from the south and west. A transit of the sky can take anywhere from one to five minutes, and from earth it looks like it's about as fast as a fast airplane.

The times of these overflights are unpredictable enough that you need to know when and where to look to see it coming; of course, you also need to have the notoriously cloudy Michigan skies working in your favor. Here's an upcoming schedule - it's flying over Ann Arbor regularly.

Four exposures of the International Space Station as passed overhead Ann Arbor are stacked together in this photograph. The first two exposures were 5 seconds long, the 3rd 4 seconds, and the 4th 2.5 seconds. (Photo credit: Spencer Thomas)  

Follow twisst on Twitter

I generally find out about the ISS by following the Twitter service Twisst, which is run by Dutch journalist and web developer Jaap Meijers, together with science reporter Govert Schilling. If your Twitter account has a location set, Twisst sends you an alert a few hours ahead of time when the ISS will be overhead. That service doesn't know about cloudy weather, but it does predict how bright the ISS will be and where it will be in the sky. My personal prediction page says that the next visit is Thursday, November 12, 2009, at 18:09:41 EST; the station will be flying over 42 degrees above the horizon, and that the brightness is magnitude -2.5, brighter than the brightest star and almost as bright as Mars. It will come from the west-southwest.

Find the ISS on your iPhone

There are a number of iPhone applications that let you track the ISS, including Satellites from Ann Arbor resident Gavin Eadie. I don't have an iPhone to test this with, so I'll leave additional reviews of those apps to the rest of you.

Plan ahead with NASA

NASA's Human Space Flight group prints a schedule of the upcoming two weeks worth of flight plans - here's their schedule for Ann Arbor and an excerpt from it:

THE FOLLOWING ISS SIGHTINGS ARE POSSIBLE FROM TUE NOV 10 TO WED NOV 25