Now you see it — with Twitter's help
The International Space Station whizzes over our heads at the speed of more than 17,000 miles per hour. Even though it's more than 200 miles overhead, you can occasionally catch a glimpse of it.
Want to see it? Well, you need a dark sky, probably a view that reaches close to the horizon, and some data.
Data? Yep. The space station eventually passes over most points of the globe (Sorry, Alaska, you're out of luck). But the question is, when does it reach that sweet spot... not only above the place where you live, but at a time when the space station is lit by sunlight and you are in the dark?
NASA's happy to help you find the sweet spot. Check here and choose your location to get a list of upcoming space station appearances.
You can also get an alert via Twitter (follow @twisst) when the manned satellite is about to be overhead where you live.
Dutch science reporter Govert Schilling and journalist Jaap Meijers have built a Twitter service that will alert you to every upcoming encounter, based on the location you put in your Twitter profile. (Note: This particular service has already proved so popular that the site has repeatedly reached its limit of permitted "followers" this week. The founders say they're in negotiations with Twittter to increase that limit. In the meantime, check the website to figure out when to look up).
It's a fun way to see your tax dollars at work. Or at least in orbit.