The International Space Station orbits the Earth 16 times a day, giving space gawkers several chances to wave to their neighbors in the thermosphere. Because of its relatively close proximity to Earth, it can be viewed with few resources and the right timing.
The station travels up to 17,000 mph some 250 miles from land. That’s roughly the distance from New York to Washington DC, or from Los Angeles to Las Vegas. The International Space Station orbits our planet every 90 minutes, allowing its crew members to see 16 sunsets and sunrises in 24 hours.
An optimal time for us to spot the ISS is either right before sunrise or right after sunset, when it’s dark enough to see the reflection of the station’s solar panels. The panels attached to either end of the space station stretch to 112 feet long by 39 feet wide.
It’s also constantly rotating to always face the sun’s beam, which becomes the glimmering signal allowing people on Earth to see the station with the naked eye.
Without the use of viewing aids, people might mistake the station for a slow shooting star with gold and silver hues; some may mistake it for an airplane missing its flashing lights.
With the assistance of binoculars, viewers can see a slight silhouette with silver and gold hues reflecting off the station’s solar panel source.
The use of a telescope, however, would be counterintuitive: The speed of the station makes it difficult to track. You’re likely to be constantly attempting to refocus your aim.
The station flies by at 5 miles per second, so viewing time can be less than a minute or as long as five minutes.
NASA has created online tools to track the ISS. You can set phone notifications for when it will be viewable in your area.
These user-friendly tools include a map of up to 67,000 geo-located sites, which will list the direction the station will be traveling from, and where to, depending on your location. It will also list the exact time it will be visible and for how long.
NASA’s online tools also include a live map that illustrates the visible sunlight in each part of the globe. It plots the path the station will be headed for the next hour and a half, so viewers can gauge in real time where it will be in relation to them.
Several apps, such as ISS Finder and Go ISS Watch, provide similar real-time maps.