How To Spot The ISS In Your Sky

Anyone with even the smallest interest in the cosmos knows that you can spot the International Space Station from the ground on earth, but actually knowing where to look, and when, can be a little more tricky.

Maybe you are interested in seeing it for yourself (without having to leave the comfort of solid ground, that is), or have already given it a go and not had much success.

Thankfully for you, we have written this handy guide for you to follow, if you want to spot the ISS from your own part of the world. Read on to learn all you will need to know before seeing the ISS.

Why Can We Spot The ISS From Earth?

It is a well-known fact that the ISS can be seen from the ground on earth, but you might be wondering why we can see the ISS so clearly but can have trouble seeing other satellites that orbit the earth.

You can spot the space station from most places on earth, so long as you have clear night skies. To the naked human eye, it looks like a bright star moving across the sky from horizon to horizon for all of us on earth.

It moves very quickly, and to us, it seems like as soon as it appears it disappears.

It can be seen because the International Space Station is the earth’s biggest artificial satellite (the moon is the earth’s largest satellite).

Not only that, but it is one of the brightest objects in the sky (after the sun and the moon), because it is an incredibly good reflector of sunlight.

The ISS whizzes around the earth very fast, making a full orbit of the planet every 90 minutes, and travels at a speed of 28,000 km per hour (in comparison to this stat, airplanes fly at a speed of around 900 km per hour).

This means that opportunities to see the ISS are usually pretty frequent (dependent on your location in relation to the ISS’s orbit). Sighting opportunities in your area can range from once a month, to several times per week.

During summer in the Northern Hemisphere, the ISS receives enough sunlight to make it visible at all times of the night, but at other times of the year, the ISS typically only gets enough light to be visible during sunset or sunrise phases, as it is too dark in the middle of the night for us to see any reflections against the night sky.

How To Spot The ISS

In order to spot the International Space Station, you need to first look up when the station will be visible in your location.

To do this, enter your location into the ‘Spot the Station website, which is run by NASA (https://spotthestation.nasa.gov/), which will tell you when the station will be overhead in your area, and which direction you should look in.

The ‘Spot the Station’ website also has the function where you can sign up to receive alerts approximately 12 hours before each sighting opportunity overhead in your area.

In addition to times and directions, the NASA Spot the Station service will show you a degree value, which is the height at which the station will appear in your sky in degrees.

When reading and understanding this value, you should know that 90 degrees will be directly above your head, and any less than 90 degrees means that the ISS will appear between the overhead mark and the horizon.

Do be careful to make sure that you look for sightings with a maximum height that matches your area and requirements.

For Example, if you live in a place with a lot of tall buildings, look for sightings that have been labeled at the latest 40 degrees, as any lower than this, and there is a pretty good chance that the ISS will be obscured by buildings in your area.

If you want a quick and easy (and equipment-free) way of measuring degrees across the sky’s dome, then you can use your hands to work it out.

Make a fist, and stretch your arm out all the way. Your fist, when held away from your body at arm’s length, is equivalent to around 10 degrees. Then, just use the appropriate number of fist-lengths to find where the ISS will appear in your sky.

For example, if the ISS is due to appear 50 degrees from the horizon, then you should measure five fist lengths away from the horizon to find where it should appear.

If you aren’t sure about the compass directions in your location, then you just need to note where in the sky the sun rises and sets – as the sun generally rises in the east and sets in the west.

From this information, you can calculate where the ISS will appear in your night’s sky.

A Short History Of The International Space Station

The International Space Station has been orbiting the earth since its first module was launched in 1998, and the initial construction took around two years to complete.

After the construction of the ISS was finished, human occupation began in November of 2000, and Since then, it has been continually occupied.

The ISS served as an orbiting space laboratory, as well as a port for international spacecraft. It orbits at approximately 220 miles (354.06 km) (which is equivalent to 350 km) above the earth’s crust.

It travels at an average speed of 17,227 miles per hour (which is equivalent to 27,724 km per hour).

Furthermore, it travels so fast that it makes multiple orbits around the earth every day, and orbits the earth fully around every 90 minutes per second.

Though the ISS is international, there are a few primary partnering countries, which include the United States (whose space agency is NASA), Canada (who have CSA), Japan (which have JAXA), several different European countries, and Russia (who have the space agency Roscosmos).

As of 2022, China is building their own space station, separate from other nations, which they have called Tiangong, and launched the first module of this station in 2021.

Final Thoughts

The International Space Station is the largest man-made object that can be seen in outer space. It is visible from anywhere in the world, if the time and weather conditions are right.

It is around the size of a football field, and has been continually inhabited by at least (and up to six) astronauts since the second of November, in 2000.

It is one of the easiest objects that you can find in your night sky, and you don’t have to invest in any telescopes or fancy equipment.

Even in brightly lit urban areas, it can be seen and is brighter than Venus.

You can identify the ISS in your night sky by finding when it will be overhead using NASA’s Spot the Station website.

Initially, it might look like an airplane, but you will be able to tell that it is not by the steady movement, and lack of flashing lights as it grows nearer and brighter.