The ISS (International Space Station) orbits above our heads and you probably don’t ever think about it. The ISS orbits the Earth every hour and a half. While it might not sound easy to see, the ISS is large enough that you can see it as it passes over. It’s a true feat to build something big enough it can be seen from the Earth.
The reason you can see it is the same reason you can see the moon, sunlight bounces off it and back onto the earth, but it’s not bright enough to see it during the day. In order to see it the ISS generally needs to be above you during the night when it passes over.
There are many ways that you can track the ISS. NASA has a page just for tracking the ISS. Here. There are many more programs that track the ISS. Many more websites are available at a quick Google search.
NASA also has a page that provides the resources for finding out more information about the passages, such as when it passes into visibility, and the viability of the ISS sighting. here.
What do you need to know to see the ISS?
First, make sure that it’s going in a sight-line. A misconception is that it needs to pass directly above you, but that’s not true; however, it does make it easier to see the ISS. It just needs to be within the area you can see, from the ground, because of this it’s able to be seen twice in a night an hour and a half apart, on a good day.
Second, it needs to be night or twilight. You need it to be dark enough so when it passes you can see the minimal light that bounces back.
Third, it needs to be a mostly clear sky. If you can’t see stars, you’re not likely to see the ISS.
Finally, you need something to track it with (unless you see it by accident). You can find the ISS with a compass looking up at what degree of north it will appear at. You can also use your phone with a tracking app to locate it easier.