Iridum Flare in D.C.

So there was a weird light in the sky last night right around 9p.m. I envisioned aliens or some some apocalyptic event, but turns out it was an Iridium Flare, which is a sunflare from a satellite in orbit.
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 or longer.







