2013-10-30 - Modesto, CA - Flash

Stationary blinking white light

Approximate date of sighting 10/29 or 10/30, approximate time 9-10 pm.

I was outside in my backyard briefly letting the dog out, and looked up at the night sky, as I frequently do on a clear night. Within my peripheral vision, I caught a rather bright flash (approximate astronomical magnitude -5) of white light of less than 1 second duration. I would estimate the size of the light to be slightly larger than the planet Venus, and was noted at the straight overhead position, 90 degrees above the horizon. This white blinking light reoccured several times, at an interval of ~10-15 seconds, and for a total duration of less than 1 minute. It then abruptly stopped. The blinking light remained in the exact same position throughout that time. My impression is that it had an altitude of at least 20,000 feet, but possibly greater. No associated object/fuselage could be observed. I would say that it had a very similar appearance to a bright, blinking white beacon light that one would observe atop a radio transmitter tower. It was definitely not an aircraft navigational light.

I am an experienced observer of the night sky. I am familiar with the commercial aircraft on their approach pattern to SFO (that path is due south of my location), and all the visible planets and 1st magnitude stars. This was also not the ISS, a satellite, meteor, nor an iridium flare.