If You Like Spotting Aircraft, Try Spotting IRIDIUM FLARES!

Spotting aircraft using FlightAware reminds me of a similar “hobby” I discovered a couple of years ago.

There is something called IRIDIUM FLARES which you can spot with the help of the Web. An Iridium flare is a short-lived (just a few seconds) reflection of the Sun off of the highly reflective antennae on the constellation of 66 Iridium satellites. The flares can be predicted with split-second accuracy for any spot on Earth. They are best seen during windows of an hour or two prior to local sunrise and after local sunset, when the sky is dark and the Sun is below the horizon. The brightest flares can be seen even in a relatively bright sky. You have to know when and where (azimuth and elevation) to look for them. One major difference as compared to spotting aircraft is that satellite spotting is extremely predictable. Satellites do not change their routes, speed or altitude, so you can accurately predict their location, even days, months or years into the future (notwithstanding orbital corrections). It’s really very cool when you do spot one.

Check out this link -

heavens-above.com/iridium.as … =CST&Dur=7

…which will show you the flares for the next 7 days that will be visible from Houston, TX (home of FlightAware), weather permitting. You can plug in your city for local predictions.

Here’s an explanation of Iridium Flares (or just Google the phrase)…

heavens-above.com/ShowFAQ.as … &FAQID=402

For even more info on Iridium, check out Wikipedia…


I’ve seen quite a few flares in the past few years, plus two daytime flares, which are hard to spot, but very cool to see. It took me a year and a half of spotting before I saw one.

I really enjoy spotting the ISS also, since it’s neat to think that the speeding bright object you’re looking at has some other human beings on it.

Anyone have pictures of these??? I have never heard of these. I don’t think I’ll be seeing any of these do to the fact that I can’t see the horizon because of mountains and woods around my house.

This is what it looks like:


Search for them on Google Images, there’s tons more.

And I have seen many quite a bit above the horizon, so that doesn’t mean you can’t see them. Check the “Alt.” value, the closer it is to 90 degrees, the higher in the sky the flare is.

I have seen these. Really neat! Just really a reflection off a really long antenna.

The link to **Heavens-Above **is the best place to start in finding these. Some nights, I’ll line up a time when there is a cluster of satellites within a few minutes of each other.

Vanguard, USA’s first orbiting satellite is still up there.

I was looking for a place on heavens-above to type in my location and find when these flares will happen but I can’t seem to find this page.

heavens-above.com/main.asp?L … =68&TZ=EST

Here you is!

Thank You

Newark777 check the PM

It should be pointed out that the reason photos of these flares look like a long streak with a brighter central region is that they are time lapse photos taken over several seconds.

When observing the flares, they appear to be a moving star that starts dim, brightens quickly, and dims again before disappearing, all within a couple of seconds. It is only a pinpoint object at any instant in time, and never appears to the observer as the long streak you see on the photos.

When querying the heavens-above database, you may get a few weeks where all of the good flares happen low to the horizon. Keep checking weekly and after a while you’ll start seeing positions higher in the sky. The lower the magnitude value, the brighter the flare. A -8 is a spectacular sight - like a distant plane’s landing light coming at you head-on for a brief moment. Just keep in mind that the satellite is over 450 miles away!