Wednesday, June 28, 2006

Iridium Flare Spotting

My brother got me into a bizarre thing. Iridium Flare spotting. It's slightly cooler than train spotting but not much. Can't be bothered explaining what an iridium flare is so here's a quote from the FAQ's.

"An Iridium flare is caused by the sun being reflected from one of the three main mission antennae (MMA) of an Iridium satellite. The MMAs are flat, highly polished aluminium surfaces, and when the angles are just right, they can reflect the sun just like a mirror. There are over 80 of these communications satellites in orbit, and they are operated by the Iridium LLC Consortium."

So there is this website where you can put in your location and it will tell you what 'iridium flares' will be visible tonight (if you have a clear sky).

For instance tonight in Maastricht:

The second two are a bit late but the first one at 11.27 I'm gonna try and see. 'Alt' is how high it is in the sky so 29 degrees up from the horizon. Azimuth is where on the compass it is so Westish. The distance is unimportant, as is the Intensity to flare centre. Satellite is the name of the satellite. They were imaginatively named 1-80.

The important bit is the first Intensity as that is how bright it will get when it flares. You can see the satellite before it flares like you can see most satellites.

'-5' is the magnitude of the one tonight. For comparison the brightest star in the sky (sirius) is '-1.44' . The moon is -12.7. So imagine that the moon lights up the streets. '-5' should be quite bright. the flare usually lasts about 2-3 secs, as the satellite revolves.

At first i thought it would be quite boring doing this but the fact that if you are there and looking at the right place at the right time and see an object 780km high up which is not visible normally is quite thrilling.

It is even possible to see Iridium flares in the daytime appraently, much harder but possible. Maybe thats what Truman Burbank saw in 'The Truman Show'. Wouldn't surprise me if they have also been many times mistaken for UFO's. When you see a picture of one.


The New Dutchman said...

I think I'll give this a try tonight if I think of it. I got one at 22:58 and one at 23:50..

The New Dutchman said...

Nope didn't see it.. the part of the sky where it was supposed to appear was the only part that was cloudy!

Polarbear said...

bloody hell
i added cardiff to my locations to see hwta you were looking for and fogot to change it back to maastricht
been looking for shit i would not see the last few nights