Fourmilab Photo Album Wednesday, March 21, 2012

Iridium flare at twilight, magnitude −8.

This image shows a flare of sunlight reflected from the main mission antenna of Iridium 81. The peak of the flare was at 18:37:33 UTC on 2012-03-21 at magnitude −8 as observed from Fourmilab (the flare centre was about 600 metres east of where I took this picture). The photo is a 45 second exposure at ISO 160 with a Leica M9 with a SUMMICRON-M 1:2/35 ASPH 35mm lens at f/2. I made the exposure manually with a shutter setting of “B” using a cable release. Here is a map of the sky at the time of the flare courtesy of Your Sky. You can get free custom predictions of Iridium flares for your location from Heavens Above.

This document and all images included within it are in the public domain. They may be used in any manner without permission, restriction, attribution, or compensation.

by John Walker

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