Sep. 30, 2013 at 2:47 PM ET
SpaceX's first-ever Falcon 9 launch from California gave a big boost to commercial spaceflight — but it also boosted our planet's store of UFO lore.
Reports about a fuzzy-looking unidentified flying object streamed in from observers in southern Africa and the Indian Ocean islands of Mauritius and Reunion. The sightings came about an hour after the Falcon 9 v1.1 rocket's launch from Vandenberg Air Force Base at 9 a.m. PT (noon ET) Sunday.
The Zimbabwe Mail marveled over the "strange moonlike object" seen from the country's Mashonaland region, as well as from Botswana, Malawi and South Africa. Mauritius' L'Express wondered whether it was a UFO, a satellite or a star cluster.
A retired astronomer from Cape Town, Greg Roberts, gave the correct explanation in an interview with The New Age, a South African publication: "It was propellant or rocket fuel" released by the Falcon 9 rocket's second stage.
After sending several satellites into a pole-to-pole orbit, the Falcon's second stage released its leftover fuel, which is standard procedure to avoid a blowup during its atmospheric re-entry.
"This release by chance coincided with sunset beneath that part of the orbit, as the booster and its deployed satellites flew from south to north directly over Madagascar, about 850 miles high," NBC News space analyst James Oberg explained in an email. Sunlight set the cloud of rocket fuel aglow.
In a Tumblr post, rocket scientist Ben Brockert speculated that the fuel release might be related to a reported anomaly in the attempted restart of the second-stage rocket engine. Reddit has more chatter about the rocket report.
This sort of phenomenon has been seen many times before — and the bottom line is that you can expect an uptick in UFO reports anytime there's a rocket launch, particularly when the rocket is blazing a new trail, like this brand-new breed of Falcon.
More rocket UFO reports:
Tip o' the Log to James Oberg.
Alan Boyle is NBCNews.com's science editor. Connect with the Cosmic Log community by "liking" the NBC News Science Facebook page, following @b0yle on Twitter and adding +Alan Boyle to your Google+ circles. To keep up with NBCNews.com's 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.