Sunday, August 07, 2011

How would you like to see an Iridium flare?

I showed Darlene her first Iridium flare a couple nights ago. Why does everything have to sound dirty? Anyway, everyone has seen satellites passing overhead at night, but Iridium flares are a tad more exciting. For those not 'in the know', Iridium satellites are for satellite telephone calls. There are a few of them and they have polar orbits. What is unique about these celestial bodies is that they have a very polished set of antennae on the bottom that at the right angle reflects a lot of sunlight. As an astronomer friend put it: "You'll see movement, then it will get brighter and brighter and in some cases brighter still, then peter out to nothing. It's as if someone held up a boy scout mirror in orbit."

If you'd like to see an Iridium flare, you need to go to heavens-above and tell it where you are by clicking on 'select from map' in the Configuration section. You do this by zooming in on the map and double-clicking on the spot where you are, choose your time zone, then clicking 'Submit'. Make sure you place yourself within the block of where you are, otherwise the calculations will be skewed. Once you've got your location and time zone plugged in, go back to the home page and click the link for Iridium Flares 'next 7 days'. The intensity figure is the key. The lower the number (in the negative), the brighter the flare. If the intensity of the flare isn't strong enough to warrant looking at from your location, you just have to go to the flare's centre to experience it. So if a particular flare is situated 25km west of your present location and is a magnitude -9 (intensity at flare centre), a drive 25 km west will witness a great flare at the prescribed time. The azimuth figure indicates which direction in the sky to look and the Alt. figure indicates how far up (90 degrees is straight up).

If you're still not getting it, give me a call and I'll help you out. Pictured is a time lapse of a flare.


AW said...

It appears there's an app to find iridium flares!


Karl Plesz said...

Why am I not surprised? That's cool.