Rotating orb of streaks of blue light in the sky over Alaska
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Scientists have solved the mystery of a spinning orb of bluish light that slowly streaked the sky over Alaska last month, stealing the show from the famous Northern Lights: the unusual ball was most likely debris from a Chinese rocket passing overhead.
Eyewitnesses across the state spotted the strange phenomenon on March 29 around 5 a.m. local time. “It looked like there was something spinning inside,” Leslie Smallwood, a Fairbanks resident who witnessed the event, told the local news station. KUAC (opens in a new tab). The orb appeared much larger than a full moon and moved from northeast to southwest, he added.
An automatic camera trap captured images of the orb streaking past the northern Lights (also called aurora borealis). The camera trap, operated by The aurora hunters (opens in a new tab) Ronn Murray and Marketa Murray, a husband and wife duo from Fairbanks who run Northern Lights photography tours, routinely take photos of the sky every 45 seconds so people can experience the Northern Lights in near real time. The camera took six pictures of the orb, suggesting it was visible for at least four and a half minutes.
“It’s not like he crossed the sky,” Smallwood told KUAC. “It was like taking your time.”
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The orb moved back and forth without any real explanation. However, after analyzing the photos, scientists determined that the large blue ball was likely the result of a photobombing Chinese rocket.
“I’m very confident that what people saw was fuel spillage from a Chinese rocket stage,” Jonathan McDowell, an astronomer at the Harvard Smithsonian Center for Astrophysics in Massachusetts, told KUAC. The orb matched the flight path of a Chinese rocket launching two satellites into orbit, he added. The rocket was a two-stage Long March 6 carrier rocket launched from Taiwan, according to a Tweeter (opens in a new tab) by McDowell.
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The rocket likely released remnants of fuel into space, where the fuel froze and spread out into a large ball illuminated by sunlight, McDowell told KUAC. “This cloud is probably hundreds of kilometers across, which is why it looks so big,” he added.
Other scientists agree with McDowell’s explanation. “A glowing cloud of gas lit by the sun would look like this,” Mark Conde, a physicist at the University of Alaska Fairbanks, told KUAC.
The orb appeared to spin because as the rockets discharge their fuel, they enter a controlled fall to maintain the rocket’s orbit. The rocket would have spun “from end to end while spitting out that fuel like a garden hose,” McDowell said.
This is not the first time this phenomenon has occurred. In October 2017, an even larger blue orb was seen in the sky over Siberia, according to Scientific alert (opens in a new tab). On this occasion, frozen fuel was left over from Russian military rocket tests in the area.
Originally posted on Live Science.