As you probably already know I do like to look up every now and then and recently I saw an article online about the International Space Station that fascinated me. Did you know that it’s the largest artificial body on orbit around our planet and that you can see it without any fancy equipment, all your need is a dark night and your eyes!
The ISS orbits the earth once every 90 minutes, travelling at a velocity of 27,600 km per hour (about 5 minutes a second)! It is permanently inhabited with scientists and zipps round at about 400km above our heads. It’s a common mis-conception that the ISS stays in place because of a lack of gravity, in fact it’s more accurate to think of it as constantly falling over the horizon of earth, it’s essentially in a constant `free fall`around our planet. At 400 tons it’s not a small thing but because of the millions of pieces of space debris also orbiting the earth, the ISS does need to be able to move to avoid the larger pieces – having your tin can punctured by a piece of rubbish moving at over 27,000 kmph would seriously negatively impact your day I would imagine! In order to move the ISS to avoid contact with these objects the crew use a team of people on earth whose job it is to track each of the items that are large enough to cause serious harm (around half a million of them), once an item is identified as being on a collision course (or a possible collision course) then the thrusters and gyroscopes on the ISS come into play to move the ISS out of the way – all of this is controlled from the ground, the guys in the “tin can” don’t have to do anything, although sometimes if a smaller object has hit the solar panels they may be called upon to perform a space walk to investigate and repair things outside.
Something that you might like to do one evening is to watch the ISS pass overhead. It is great to think that we can be sitting here on earth watching something man made pass overhead at such a speed and wonder at the technology that developed, built, and keeps it all there orbiting our little blue dot. There are plenty of websites and apps that allow you to track and predict where the ISS will pass overhead. What you need to try to do is be in as dark a place as possible with as much of the horizon viewable as you can (being in the middle of a housing estate isn’t going to help for example, but being on a roof terrace high up would be a great spot)!
The website https://spotthestation.nasa.gov/sightings is a great resource to allow you to plan your viewing evening. Just enter your country and town and it will spit out dates and times when the ISS will be overhead in your area. What you need to do is to select a time when it will be dark enough (any time after around 22:15 at the moment is good, and a height that suits good viewing, i.e. anything over 45 degrees is perfect but this really depends on what is around your viewing area of course. The website will tell you where to look, at what time and in which direction. It will tell you how long the ISS will be visible – it moves very quickly through the sky, much quicker than the aircraft we are all used to seeing and it doesn’t flash, although it will be one of the brightest objects in the sky so it should be fairly easy to spot.
Why not pick a night and have a look up, you won’t be disappointed.