Searching for Iridium Flares

Iridium flares are pretty easy to spot for anyone who is out looking at the night sky just after sunset or before sunrise.

There is a constellation of small communications satellites that are known as Iridium, each with three highly reflective antennae that face toward the earth. These antennae reflect sunlight earthward. The reflected light cuts a swath several tens of kilometers wide on the earth's surface. If you are in the right position at the right time, then flare or flash will appear in the sky for several seconds. Sometimes these flashes can be brighter than Venus.

The best times to look for Iridium flares are just after sunset, or before sunrise. The good news is that you do not have to spend hours searching in vain for these flashes. The Heavens-Above website calculates when the next flash will be visible for your location. The key is to enter the most accurate location you have to get the best prediction. I have found the information provided by the website to be quite accurate. I have gone out at the appointed time, peaked up at the sky at the location the site predicts, and viola! A flare!

There is also great information about satellite observing, planets, and the moon. What I like best about Heavens-Above is that the page is does not have unnecessary graphics, loads quickly, and easy to use.