New Studies Argue Distant Cosmic Gamma-Ray Explosion Was Actually Just Russian Space Junk (science.org) 16
"Last year, a team of astronomers made a blockbuster claim, saying they had captured the most distant cosmic explosion ever — a gamma ray burst in a galaxy called GN-z11," reports Science magazine.
"But that flash of light — supposedly from the most distant galaxy known — has a far more prosaic explanation: It was a glinting reflection from a tumbling, spent Russian rocket that happened to photobomb observers at just the right moment, two new studies claim..." Although they happen all the time, the chances of catching one when a telescope is pointed at a particular galaxy are quite slim. So it was even more surprising when astronomer Linhua Jiang of Peking University and colleagues claimed — using data from the W. M. Keck Observatory in Hawaii — to find a burst coming from GN-z11, a galaxy dating back to a mere 420 million years after the big bang. Indeed, the team itself reported in December 2020 that the odds of catching such a burst were one in 10 billion.
Those odds raised red flags for Charles Steinhardt, an astronomer at the University of Copenhagen. "You start asking," he says, "'Are there any other causes that are more likely?'"
That's where the Russian rocket comes in. Humans have launched and left behind large numbers of objects in orbit around Earth, including satellites, rocket boosters, and even screwdrivers gone missing during spacewalks. Up to half a million bits of metal larger than 1 centimeter are thought to be tumbling around our planet. Glints of sunlight reflecting off this debris could be responsible for as many as 10,000 flashes of light per hour throughout the night sky, estimates Eran Ofek, an astrophysicist at the Weizmann Institute of Science who has published independent analyses of this phenomenon. The vast majority are invisible to the naked eye, he says, but they can be discernable to astronomical observatories.
Given such potential light pollution, the possibility of finding a debris glint in a random telescope image is somewhere between one in 1000 and one in 10,000, Steinhardt and his collaborators calculate in one of the new studies, published today in Nature Astronomy. That seems more likely than the one-in-10-billion chance of a gamma ray burst, Steinhardt says. "If you have to pick between the two answers, yes they're both unlikely, but one of them is millions of times more likely."
"But that flash of light — supposedly from the most distant galaxy known — has a far more prosaic explanation: It was a glinting reflection from a tumbling, spent Russian rocket that happened to photobomb observers at just the right moment, two new studies claim..." Although they happen all the time, the chances of catching one when a telescope is pointed at a particular galaxy are quite slim. So it was even more surprising when astronomer Linhua Jiang of Peking University and colleagues claimed — using data from the W. M. Keck Observatory in Hawaii — to find a burst coming from GN-z11, a galaxy dating back to a mere 420 million years after the big bang. Indeed, the team itself reported in December 2020 that the odds of catching such a burst were one in 10 billion.
Those odds raised red flags for Charles Steinhardt, an astronomer at the University of Copenhagen. "You start asking," he says, "'Are there any other causes that are more likely?'"
That's where the Russian rocket comes in. Humans have launched and left behind large numbers of objects in orbit around Earth, including satellites, rocket boosters, and even screwdrivers gone missing during spacewalks. Up to half a million bits of metal larger than 1 centimeter are thought to be tumbling around our planet. Glints of sunlight reflecting off this debris could be responsible for as many as 10,000 flashes of light per hour throughout the night sky, estimates Eran Ofek, an astrophysicist at the Weizmann Institute of Science who has published independent analyses of this phenomenon. The vast majority are invisible to the naked eye, he says, but they can be discernable to astronomical observatories.
Given such potential light pollution, the possibility of finding a debris glint in a random telescope image is somewhere between one in 1000 and one in 10,000, Steinhardt and his collaborators calculate in one of the new studies, published today in Nature Astronomy. That seems more likely than the one-in-10-billion chance of a gamma ray burst, Steinhardt says. "If you have to pick between the two answers, yes they're both unlikely, but one of them is millions of times more likely."
Excession? (Score:4, Funny)
4) [tight beam, M16, relay, received @ n4.28.855.0085]:
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Developmental anomaly provisionally rated EqT, potentially jeopardising, found here C9259969+5331.
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Instigating all other Extreme precautions.
oo
5) [broadcast Mclear, received @ n4.28. 855.01. ]:
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& *broadcast*:
Ref. 3 previous compacs & precursor broadcast.
Panic over.
I misinterpreted.
It's a Scapsile Vault Craft.
Ho hum.
Sorry.
Full Internal Report to follow immediately in High Embarrassment Factor code.
BSTS. H&H. BTB.
Glimpse of the future (Score:2)
I'd be very disappointed of the humanity unless someone's frozen poo either initiates the Kessler syndrome or becomes a scientific blockbuster find, when in space hotel era.
Does space junk reflect gamma rays? (Score:2)
Will a rocket booster reflect gamma rays? If not then the presence of space junk is irrelevant.
Re: (Score:2)
Re: (Score:3)
Gamma Rays from that distance are redshifted so far, they are no longer gamma rays.
So they won't affect Man-in-the-Moon Marigolds [amazon.com]?
Infrared burst [Re:Does space junk reflect gamma] (Score:5, Informative)
Will a rocket booster reflect gamma rays? If not then the presence of space junk is irrelevant.
A good question, but no, the burst detected was infrared.
"Gamma ray bursts" also produce transients in the optical/UV range (which get redshifted to IR).
The article on the original detection is here: https://www.nature.com/article... [nature.com]
Selected quotes from this article: "Here, we report a near-infrared transient with an observed duration shorter than 245s that is coincident with the luminous star-forming galaxy GN-z11 at z11.... As some long-duration GRBs are associated with a bright ultraviolet or optical flash, we investigate the possibility that the detected signal arose from a rest-frame ultraviolet flash associated with a long GRB ..."
Re: (Score:2)
with an observed duration shorter than 245s
245 seconds? That's not really tumbling in the strict sense of the word anymore. A continuous(?) signal with a duration of 4 minutes must be keeping one face toward the observer to the extent that it could be considered to have a stable attitude. And for such an object to maintain a fixed position relative to a distant object (galaxy) for this period of time would imply that it is in a very high orbit above the Earth.
Re: (Score:3)
with an observed duration shorter than 245s
245 seconds?
Shorter than 245 seconds.
Unfortunately, only the abstract of the paper is available without paying... can't tell how long the flash actually was, or how they took the measurement or what the field of view was. If, for example, they compared frames two minutes apart, you wouldn't be able to tell how long the burst was, only that it didn't last as long at two frames.
Re:Infrared burst [Re:Does space junk reflect gamm (Score:5, Informative)
https://arxiv.org/pdf/2012.069... [arxiv.org]
They saw it on one frame. Their exposure time was 179 s, with 33 s between exposures. So less than 245 s, but nobody can say how much less.
PS: If you're interested in a paper that's paywalled, copy the title into google scholar and it will often pop up a free link. If that fails, paste into scihub.
Re: (Score:2)
Their exposure time was 179 s
Still, most space junk moving in Earth orbit will leave a streak on a 3 minute exposure relative to the background space.
Re: (Score:3)
Not if it's tumbling.
The argument is based on probability. The chances of the original interpretation of the explosion are extremely remote. The chances of space junk causing the observation are also remote, but apparently *much less* remote. Arguing "most space junk...", even if it was true, won't budge the odds much.
Ugh (Score:3)
Nobody want's to see a Russian's junk.
Re: (Score:2)
Nobody want's to see Russia's junk.
The gamma ray explosion was so intense it's orbiting Uranus.
Russian again ? (Score:1)
They are root of everything on earth it seems. Maybe God is Russia.