Space Stations & Iridium Flares

Planets, Stars and Deep Space Objects aren't the only thing you can see by looking up at night. You should easily be able to see the odd tiny spot of light moving quickly across the sky which is of course one of the many satellites which orbit the Earth. These satellites range from the rather huge International Space Station to space debris like discarded rocket boosters. An interesting tool to find out what satellites are passing overhead is Heavens Above, this is a website where you enter your location and it gives you the time a satellite will pass along with its actual path across the sky.

Amazingly enough one object I had never actually seen was the International Space Station even though it is quite bright in the night sky. Therefore I used Heavens Above to find it when it would be visible from my back garden and went out to have a look. Its magnitude was supposedly -2.5 and I have to admit it was very obvious moving across the night sky. I managed to get a 15 second exposure of its transit across the night sky which you can see below. It is quite an amazing site when you realise that what you are seeing is a man made space station with people on board.

Another interesting thing I noticed whilst on Heavens Above is that there is something called Iridium Flares which seem to happen quite consistently every night and actually get up to a magnitude of around -8.5 which is brighter than Venus. It turns out that a satellite flare is the phenomenon caused by the reflective surfaces on satellites (such as antennas or solar panels) reflecting sunlight directly onto the Earth below and appearing as a brief, bright "flare". The Iridium Communications Satellite has a peculiar shapes which results in these flares being quite bright to the point that they can potentially even been seen in daylight.

Anyway after reading about these I decided I had to try and both see and image one of these flares. Seeing them was quite easy and I even got my normally uninterested wife to say "Wow" when she saw one of the bright flares. Imaging them however was a bit of an adventure, my first attempt failed because my timing was off and I got an image of the satellite before and after the flare, the second time was ruined by cloud cover meaning that whilst I saw the flare I failed to aim the camera correctly, the third time the satellite failed to flare for some reason and the forth time was when I forgot part of my tripod meaning I couldn't set up the camera. It was fifth time lucky however and on Easter Saturday I sat outside and finally snapped a picture which you can see below.

This wasn't actually the brightest flare I saw but at least I managed to catch it. You can see the transit of the satellite brighten in the centre which is of course where it has flared.