Jan. 4, 2013 at 2:16 PM ET
A smartphone video that shows a bright orb exploding in the sky sparked a UFO mystery in Sacramento, Calif., but it looks as if the mystery has been solved: It was a weather balloon.
That may sound like the quintessential cover story from the flying-saucer conspiracy, but in this case, the explanation makes perfect sense.
The video was shot through the eyepiece of a telescope by Elijah Prychodzko around 5 p.m. on Dec. 20, and aired by Sacramento's CBS13 television station on New Year's Eve. The first video clip shows the orb in the sky with a smaller object swinging around it. Prychodzko calling his nephew over to take a look, and then turned back to shoot another video clip.
"Oh my God, it just blew up!" Prychodzko can be heard saying. The video showed a haze of fragments floating in the air.
In its account of the Sacramento UFO incident, The Huffington Post said "nobody has come forward to officially explain the event." On the Above Top Secret forum, however, the discussion quickly turned to weather balloons. The most telling message was this one, attributed to the National Weather Service's Upper Air Observations Program:
"...It is very likely a weather balloon that burst. The small dot 'orbiting' the balloon was the radiosonde that was attached below it with about 70 to 100 feet of string.
"The weather balloon was likely released by the National Weather Service (NWS) upper air station in Oakland, California, at about 3:00 p.m. local time.
"Here is a video of a NWS weather balloon burst taken by a NWS meteorologist through a telescope: http://www.youtube.com/watch?v=0lG3zr0yaJw"
George Cline, observation program officer for the National Weather Service's office in Sacramento, confirmed that the Oakland station releases its balloons at around 3 p.m. and 3 a.m. PT — and that the flights last about an hour and a half. He noted that the timing for Prychodzko's reported sighting fits the afternoon timeline.
"That would put it right around the time for a balloon burst," Cline told NBC News.
More UFO cases put in context:
Alan Boyle is NBCNews.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter and adding the Cosmic Log page to your Google+ presence. To keep up with Cosmic Log as well as NBCNews.com's other stories about science and space, sign up for the Tech & Science newsletter, delivered to your email in-box every weekday. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.