Dazzled by an Iridium Flare

I was having my usual late night potter around at midnight last night, taking a gentle late night tour of the sky.

I've been neglecting my astronomy I know, I keep saying! There just aren't enough hours in the day or night to do everything, and I have to rest occasionally. Using binoculars makes my eyes tire very quickly at night these days. But luckily, the sky has more than enough to keep the naked eye interested.

So it proved last night. Approaching low from the south, rising up to meet the bright orange star Arcturus, was a faint satellite. I could see however that it was brightening up, so I figured out quickly what it was.

The Iridium Satellites

These are communications spacecraft who's highly reflective panels direct sunlight onto a narrow strip of the Earth below as the satellite passes about 900km up. I've seen them before, the brightest ones reaching about the same brightness as Venus, around -4 for a few seconds before the sun-satellite angle becomes unfavourable for the observer and the Iridium craft fades away again.

This one, however, became almost as bright as a half moon. It cast shadows, had a halo lighting up a quarter of the sky, and it all but hurt my eyes to look at.  It drowned out the stars for a moment, and it almost felt like a celestial god was shining a torch on my face, it was dazzling.

Outside of the moon, this was the brightest object I've ever seen in the night sky.

A twitter contact down south thought it might have been a flash of lightning.

It was actually Iridium 32, and it had reached a magnitude of a shade under -8.

You can use the "Heavens Above" website to predict views for Iridium Flares - and also things like International Space Station passes. This is the pass I observed last night. If you enter your location, it will predict and locate bright Iridium Flares for you.

They really are spectacular.

Si

All text copyright CreamCrackeredNature 12.06.15

My First Iridium Flare

Night before last, as I was undertaking a quick survey of the night sky before heading for a gloomy, work enforced bedtime, I had my first confirmed sighting of an Iridium Flare. It lasted about 20 seconds or so, and about 15 degrees of sky, as it passed through the constellation of Leo heading northwards.

It was spectacularly bright, much brighter than the International Space Station, and to me, slightly brighter than Venus, although  quick research reveals they can get as bright as mag -9. The Iridium series are communications satellites in low polar orbits, and they look like this;

(Picture from ideonexus on flickr)

The door sized antennae seen here are highly reflective, and when the satellite and the sun are in the right position, the sun is reflected down onto the earth below so observers can see it for a short time. Even occasionally in daylight if you know where to look. As well as being brighter and much shorter lasting than the passes of the International Space Station, the Iridiums travel North-South in the sky, rather than the West-East passages of the ISS.

So if you are out one night, and see a really bright, dazzlingly bright even,  star moving slowly North for a few seconds, then that's what it is. There are many Iridium satellites, apparently the one I saw was Iridium 29, and you can actually look up online to see when you might observe a flare. Believe me, it's a great sight.