Iridium Flare

The Iridium communication satellites have a peculiar shape with three polished door-sized antennas, 120 degrees apart and at 40 degree angles with the main bus. The forward mirror faces the direction in which the satellite is travelling. Occasionally an antenna will directly reflect sunlight down to the Earth, creating a predictable and quickly moving illuminated […]

The Iridium communication satellites have a peculiar shape with three polished door-sized antennas, 120 degrees apart and at 40 degree angles with the main bus. The forward mirror faces the direction in which the satellite is travelling. Occasionally an antenna will directly reflect sunlight down to the Earth, creating a predictable and quickly moving illuminated spot of about 10 km diameter. To an observer this looks like an extremely bright flare in the sky with a duration of a couple of seconds.

Some of the flares are so bright (many get up to -8 magnitude, but some get to -9.5) [1] that they can be seen at daytime, but they are most impressive at night. This flashing has been of extreme annoyance to astronomers, as the flares occasionally disturb observations and can damage sensitive equipment.

When not “flaring,” the satellites are often still just visible to the naked eye – a typical magnitude is 6, similar to a dim star.

Still Image Gallery  Gallery #1  An assortment of various images taken prior to 2005.
Still Image Gallery  Gallery #2  Wales and England, April 2005
Still Image Gallery  Gallery #3  Gabriola Island, B.C., August 2005
Still Image Gallery  Gallery #4  Finally, a CCD Astro-images gallery
Still Image Gallery  Gallery #5  Peru, November/December 2005
Slide show with music  Peru slide show  A trip to Peru, November/December 2005
Still Image Gallery  Gallery #6  Egypt and Total Eclipse gallery, April 2006
Slide show with music  Egypt slide show  Egypt and Total Eclipse, March 2006
Slide show with music  Starfest 25 slide show  The NYAA presents Starfest annually in August, one of the largest starparties in North America. In 2006 we celbrated our 25th anniversary, and here is a slide show retrospective.
Still Image Gallery  B.C. Gallery ’06  Gabriola and Hornby Islands, September 2006
Slide show with music  Barbara’s Garden  Gabriola Island, B.C. Sept 3, 2006
Slide show with music  Flight Over Canada  Take off from YVR, fly over city, smoke from forest fires south of border visible below, the terminator approchaed as we fly towards the night sky, Capella in Cephus is the bright star…note the thunderstorm sequence at the end over Bruce County. Sept 5th ’06
Slide show with music  Arizona  November, 2006
Slide show with music  Mercury Transit and Sunset time lapse sequence of images.  November 8th, 2006
Still Image Gallery  Comet McNaught  January 10th, 2007 5:35pm at 35,000 feet
Still Image Gallery  Barret Jackson  Pheonix Arizona, Jan 18-21 2007