The ISS has been a continued presence through the heavens since its 1998 launch. The celestial laboratory actually orbits our planet every 90 minutes at an approximate altitude of 250 miles (400km). And although impossible to view during the day, the space station transforms into the third brightest object in the night sky.
Entire months can pass when the ISS is invisible from the specific parts of the world such as the UK.
This is because the space station’s diagonal orbit can criss-cross other parts of the planet for long periods.
However, every now and then, a window of a few weeks opens when the ISS flies over the UK at night.
Spotting the ISS for the first can be a profound experience, when you appreciate the glowing speck streaking silently overhead is actually a scientific base to human beings conducting scientific research benefiting the world.
The International Space Station is the largest human-made object to fly in outer space and can be seen from anywhere around the world under the right conditions.
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The football field-sized space station flies over the world at speeds approaching 17,500 mph (28,000kmh).
While some may think it may be too small to see without a telescope, it is one of the easiest objects to find in the night sky with the unaided eye.
AccuWeather Astronomy Blogger Dave Samuhel said: “You can’t miss the ISS, even in urban areas, as it is as bright as Venus [the third brightest natural object in the sky].
“It will appear like a plane at first, but you will notice the steady movement without flashing lights as it grows brighter.”
Can you see the ISS tonight?
Whether or not the space station will be visible on a given day depends on its orbit and at what time of day it passes overhead.
NASA’s easy to use Spot The Station site reveals the ISS will be visible in the skies over the UK tonight – simply enter your city to reveal when to look up.
Each time the station passes overhead is different.
On some passes, the space station is very dim and is not visible for long, while other times it is incredibly bright and visible for over five minutes.
Those planning to look for the ISS should plan to view it on a night when it will be in the sky for a longer period of time.
Not only are these passes brighter, but the station will also be visible higher in the sky.
NASA International Space Station facts:
A total of 240 individuals from 19 countries have now visited the International Space Station.
An international crew of six people live and work while travelling at a speed of five miles per second, meaning, the space station makes 16 orbits of Earth in 24 hours, taking in 16 sunrises and sunsets.
Peggy Whitson set the record for spending the most total time living and working in space at 665 days on Sept. 2, 2017.
The acre of solar panels that power the station means sometimes you can look up in the sky at dawn or dusk and see the spaceship flying over your home, even if you live in a big city.
The living and working space in the station is larger than a six-bedroom house and boasts six sleeping quarters, two bathrooms, a gym, and a 360-degree view bay window.
To mitigate the loss of muscle and bone mass in the human body in microgravity, the astronauts have to exercise for at least two hours every day.