The International Space Station (ISS) is easy to spot with the naked eye if you know when and where to look. A new notification service on Twitter will tell you exactly when to go out and look up.

As with many data services and applications (or apps, as developers call them) these days, this one was created by a couple guys who were interested in the topic.

Dutch science reporter Govert Schilling and journalist/web developer Jaap Meijers created @twisst, a Twitter service that will tell you when the space station will fly over your location.

There are other online sites that provide spotting information. What's new is to get the notifications through Twitter, a social network site that's turning out to be much more.

The new service is in a test phase, according to a statement from Schilling. Twitter users can follow it at @twisst (twitter.com/twisst). Others can learn about it at a regular web site.