Last night I had a chance to see Raduga 33, my first Iridium flare : right on the predicted time and location, it lit up. Iridium flares are small communications satellites providing spectacular visible reflective flares/glints to observers on the ground. With only a normal brightness of +6 magnitude, occasionally some of the Iridium satellites provide reflective flares of magnitude -8. For comparison, Venus can be as bright as magnitude -4.9, thus reflections can be up to 30 times brighter than Venus. The flares can last anywhere from 5 to 20 seconds before the satellite once again becomes almost invisible to the naked eye.




Heavens Above is a true gold mine for satellite spotters. Its aim is to provide you with all the information you need to observe satellites such as the International Space Station and the Space Shuttle, spectacular events such as the dazzlingly bright flares from Iridium satellites by offering you detailled information and star charts.