The International Space Station (ISS) is a multi-nation laboratory, orbiting 248 miles (400 kilometers) above our heads. It perhaps comes as no surprise that the ISS can easily be seen and tracked from Earth.
The colossal structure reflects sunlight and appears as a bright white pinpoint of light in the sky. According to NASA (opens in new tab), the ISS will typically be the brightest object in the sky (except for the moon), and can even be spotted from the middle of a city.
The ISS is therefore a great skywatching target for those living in urban and rural areas alike. Spotting the ISS requires no specialist equipment as it can be seen with the naked eye. All you need to know is where to look and when.
Where and when can I see the International Space Station?
"The International Space Station's trajectory passes over more than 90% of Earth's population," according to a statement (opens in new tab) from NASA. The ISS zips around Earth at an average speed of 17,500 mph ( 28,000 km/h), completing 16 orbits per day. As the ISS orbits with an inclination of 51.6 degrees, if you live beyond 51.6 degrees north or south of the equator the ISS will never appear directly overhead.
The ISS is only visible because it reflects sunlight (opens in new tab). It isn't bright enough to be seen in the middle of the day and the best time to view the ISS is either at dawn or dusk. Viewing opportunities of the ISS can vary between one sighting a month to several a week, depending on your location and the orbit of the ISS.
NASA's spot the station widget (below) is a great tool for quickly finding out upcoming ISS viewing opportunities. Simply pop in the location you wish to know for ISS sighting opportunities and let the widget work its magic. It will tell you the time of the ISS flyover along with how long it is visible, the maximum height it will reach in the sky and which direction it will appear and disappear from your field of view.
In addition, NASA's Spot the Station website (opens in new tab) is a great place to explore ISS sighting opportunities in your area. You can even sign up for email or text alerts for when the space station is flying over so you'll never miss a viewing opportunity again. Though it's worth noting you will only get NASA's Spot the Station alerts when the ISS is passing over with a maximum height of at least 40 degrees, this is because the ISS will be visible above most landscapes at this height.
If you would like to know where the space station is right now, ESA's live map (opens in new tab) has got you covered. The informative map shows where the ISS is as well as it's speed and altitude.
The International Space Station from Earth(opens in new tab)
The ISS makes for a fun and interesting observing target in the night sky. With its location and movement tracked with great accuracy as well as night sky alerts from NASA's Spot the Station website, it's perhaps one of the easiest objects to spot in the night sky.
Related: How to photograph the ISS
Budding astrophotographers from around the world have caught beautiful long-exposure photographs that show the ISS appearing to streak across the sky. To the ground observer, the ISS passing overhead will appear as a bright point of light moving quickly across the sky, similar to a plane but brighter and without the flashing lights.(opens in new tab)
If you would like to track the ISS along with other Earth-orbiting satellites, check out the N2YO website (opens in new tab). Heavens-Above (opens in new tab) is also a good place to find more ISS tracking information as well as other astronomy resources. Both sites ask you to put in location information and generate tables with viewing times and directions to look to serve as a guide.
You can learn more (opens in new tab) about the International Space Station with ESA. Check out Transit Finder (opens in new tab) to plan observations of transit events of the ISS in front of the sun and moon. Warning: NEVER look at the sun with binoculars, a telescope or your unaided eye with out special protection. Astrophotographers and astronomers use special filters to safely observe the sun while photographing ISS transit, solar eclipses or other sun phenomena. Here's our guide on how to observe the sun safely.
- Montenbruck et al. "Orbital Determination and Prediction of the International Space Station (opens in new tab)", Journal of Spacecraft and Rockets, Volume 48, No.6, November-December 2011.
- "The International Space Station" by Clive Gifford (Wayland, 2017 (opens in new tab)).
- NASA's Spot the Station (opens in new tab).
- ESA's ISS tracking map (opens in new tab).