Interstellar Object 'Oumuamua Probably Moved Strangely Due To Gas, Study Says (npr.org) 43
Scientists have come up with a simple explanation for the strange movements of our solar system's first known visitor from another star. NPR reports: Now, though, in the journal Nature, two researchers say the answer might be the release of hydrogen from trapped reserves inside water-rich ice. That was the notion of Jennifer Bergner, an astrochemist with the University of California, Berkeley, who recalls that she initially didn't spend much time thinking about 'Oumuamua when it was first discovered. "It's not that closely related to my field. So I was like, this is a really intriguing object, but sort of moved on with my life," she says. Then she happened to attend a seminar that featured Cornell University's Darryl Seligman, who described the object's weirdness and what might account for it. One possibility he'd considered was that it was composed entirely of hydrogen ice. Others have suggested it might instead be composed of nitrogen ice.
Bergner wondered if it could just be a water-rich comet that got exposed to a lot of cosmic radiation. That radiation would release the hydrogen from the water. Then, if that hydrogen got trapped inside the ice, it could be released when the object approached the sun and began to warm up. Astronomers who observed 'Oumuamua weren't looking for that kind of hydrogen outgassing and, even if they had been, the amounts involved could have been undetectable from Earth. She teamed up with Seligman to start investigating what happens when water ice gets hit with radiation. They also did calculations to see if the object was large enough to store enough trapped hydrogen to account for the observed acceleration. And they looked to see how the structure of water ice would react to getting warmed, to see if small shifts could allow trapped gas to escape.
It turns out, this actually could account for the observed acceleration, says Bergner, who notes that the kind of "amorphous" water ice found in space has a kind of "fluffy" structure that contains empty pockets where gas can collect. As this water ice warms up, its structure begins to rearrange, she says, and "you lose your pockets for hiding hydrogen. You can form channels or cracks within the water ice as parts of it are sort of compacting." As the pockets collapse and these cracks form, the trapped hydrogen would leak out into space, giving the object a push, she says.
Bergner wondered if it could just be a water-rich comet that got exposed to a lot of cosmic radiation. That radiation would release the hydrogen from the water. Then, if that hydrogen got trapped inside the ice, it could be released when the object approached the sun and began to warm up. Astronomers who observed 'Oumuamua weren't looking for that kind of hydrogen outgassing and, even if they had been, the amounts involved could have been undetectable from Earth. She teamed up with Seligman to start investigating what happens when water ice gets hit with radiation. They also did calculations to see if the object was large enough to store enough trapped hydrogen to account for the observed acceleration. And they looked to see how the structure of water ice would react to getting warmed, to see if small shifts could allow trapped gas to escape.
It turns out, this actually could account for the observed acceleration, says Bergner, who notes that the kind of "amorphous" water ice found in space has a kind of "fluffy" structure that contains empty pockets where gas can collect. As this water ice warms up, its structure begins to rearrange, she says, and "you lose your pockets for hiding hydrogen. You can form channels or cracks within the water ice as parts of it are sort of compacting." As the pockets collapse and these cracks form, the trapped hydrogen would leak out into space, giving the object a push, she says.
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desperation? From an astrochemist and an astrophysicist? Over some rock with some odd properties? You don't really understand academia, do you.
I know I move strangely (Score:5, Funny)
Re: I know I move strangely (Score:1)
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Ancient aliens, what else could it be? (Score:4, Funny)
Only Majestic 12 know for sure.
Counterargument (Score:5, Informative)
Here's the counterargument [harvard.edu] which seems to debunk the hydrogen outgassing theory:
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the requirement for a surface layer that is made of pure molecular hydrogen
What am I missing here? Bergner's argument doesn't require a surface layer. It clearly talks about H2 being trapped under the ice.
Re: Counterargument (Score:2)
Gotta love this, science at work. Arguments and counterarguments.
No belief system tolerates let alone discusses such amicably. No belief sysyem produced anything anyone can actually use.
Science OTOH.. /me presses buttons so y'all can read my pondering.
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"No belief system tolerates let alone discusses such amicably."
You're right, I mean, as long as you disregard LITERALLY centuries of Christian internal theological arguments.
Presumably there were similar arguments within Islam (in the centuries of its intellectual golden age, and maybe even today) though I'm not deeply familiar enough with that subject to speak to it myself.
I mean, you do understand that humanism, scientific inquiry, and EVEN ATHEISM ITSELF are arguably the logical extension of some intelle
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Not to mention, I'm not sure you've ever been involved in departmental politics at a major university, but I am 100% sure I've witnessed such arguments where the participants would CHEERFULLY murder the other if they thought they could get away with it. And they have their slavering followers as well.
"Will no-one rid me of this troublesome postDoc?" - almost certain this has been uttered hundreds if not thousands of times.
Just sayin'.
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You write:
I mean, you do understand that humanism, scientific inquiry, and EVEN ATHEISM ITSELF are arguably the logical extension of some intellectual elements of Christian doctrine, as much as they are in opposition to it?
---
Really? Even the ones who refer to ancient Greek and Roman philosophies? Or Japanes? Or Chinese?
Someone needs to stick a pin in you, and let out the hot air.
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Well that's you on an NRA hit list. Unless you're talking about propelling the pin at km-s range speeds using some sophisticated chemical (or possibly rail-gun) propellant.
It must be terrifying sharing a landmass with such maniacs.
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https://www.amazon.com/Dominio... [amazon.com]
Pls, go ahead and refute! Looking forward very much to your reply.
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No belief sysyem produced anything anyone can actually use.
"Oh my science!!!" Your ignorant hatred for anything not deemed materialistic is showing through strongly. Despite your dislike of them, belief systems have contributed huge amounts to society. A simple internet search of "scientific discoveries of the church" brings up a boatload.
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Well it's fricken aliens unless scientifically proven otherwise!
Or it was aliens (Score:2)
Re:Or it was aliens (Score:5, Funny)
Because, really, isn't it always aliens in the end?
Look, only a few of them do that end thing. Many are comfortable just making crop circles and trolling people with bad camera skills.
Re: Or it was aliens (Score:3)
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Oh, come on, we know it's alien teenagers trolling the humans.
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Well, if you've ever watched Star Trek, you know that every unusual phenomenon is actually...a massive living creature of some kind that is trying to devour you.
Ptolemaic epicycles. (Score:1)
Likewise, in this case, just reverse-engineer whatever profoundly unlikely inorganic behavior could do this without violating the laws of physics and pretend that's more plausible than sentient behavior we already know occurs by virtue of us doing it.
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You are saying it's a sentient being, yet all it can do is puff out outgas hydrogen? I dunno dude, a creature that big ought to be able to make itself more visibly sentient if it was.
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pretending technology is extraordinary just because we feel like it is.
Extra funny when natural technology we experience every day is thousands, tens of thousands of years more advanced than our science based technology. We can’t even make basic self replicating, repairing, and refueling machines, much less give them general intelligence. The only thing aliens would want from our solar system they couldn’t get elsewhere is the data from billions of years of evolution unique to our planet in the visible universe. Even if it’s the only way life can arise, it
Very Cool (Score:3)
Of course, there's some nonzero chance the non-gravitational acceleration detected means there is a mechanism for self-propulsion onboard.
It doesn't necessarily indicate the visitation of/by an alien race. If mankind's dabbles with off-planet existence are any indication, the odds seem to favor a robotic ship that reports home as long as there's a mechanism to do so and a home to report to.
I'd like to think we've been observed, and a missive was sent to Central Command stating, "They're not quite ready."
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Of course, there's some nonzero chance the non-gravitational acceleration detected means there is a mechanism for self-propulsion onboard.
It doesn't necessarily indicate the visitation of/by an alien race. If mankind's dabbles with off-planet existence are any indication, the odds seem to favor a robotic ship that reports home as long as there's a mechanism to do so and a home to report to.
I'd like to think we've been observed, and a missive was sent to Central Command stating, "They're not quite ready."
I dunno. I think the message was probably more along the lines of, "No intelligent life found in this sector. Will report back on our next pass. Perhaps the ape-creatures will become sentient in the next few million years? More later, mother. Salute!"
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As long as they're not Fred Saberhagen's Berserkers....
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Well, if so, it's along the lines of the same outcome we're likely targeting as a dominant planetary life form.
Why does the likelihood of a species evolving to dominate its ecosystem doom it from expanding beyond that ecosystem?
Me Too (Score:1)
Gas has that effect on quite a few different objects
So...occams razor no longer applies? (Score:2)
There's a lot of stretching in this.
A 100m-long anything is going to have sizable mass. The mass needed to 'shove' it even a bit is likewise sizable. Our rockets -even setting aside that they're necessarily coming out of a gravity well - use a sizable fraction of their mass for fuel, and that's with carefully designed exit venturi intended to maximize the transferred velocity. So in this hypothetical model we are assuming that "hydrogen leakage" would be sizable enough to shove the primary a meaningful,
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...Is it so impossible to say that "we simply don't, and probably never will know" details about this?
This is accurate. Nobody was prepared for an unexpected interstellar comet coming in from an unexpected direction, and we don't have good observations and measurements made during the flyby that could elucidate the mechanism. We don't even know exactly when the nongravitational acceleration was produced.
Doesn't stop people from speculating, though.
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And more to the point, if the scientific community does not posit a more mundane possibility, then the *only* possibilities that will get consideration will be alien technology.
So yes, important to highlight that these are guesses, and we are debating the feasibility, but better to put 'guesses' on the table than to let only the more 'exciting' possibilities be seen as plausible.
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Was it 1I/Ou'mua'mua that was discovered after it's perihelion, or 2I/ Borisov ? Or maybe even 3I/ ToBeAnnounced ?
It's hardly surprising that the observation arc is short. What is more surprising is that the observation arc existed at all.
For the audience : the observational history of non-Keplerian accelerations in comets and asteroids is strongly concentrated to the time period about perihelion (closest approach of the body
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I'll reduce the amount of stretch - non-Keplerian motions in comets have been seen since before we had the mathematical tools to (reasonably easily) turn several nights of time-altitude-azimuth measurements into an estimate of the body's orbit in a heliocentric coordinate system. Sometimes they've been seen to associate with fragmentation of a comet (or other body, but comets were easiest to see). Sometimes a comet seen heading t
Occam's Gas (Score:4, Funny)
It was an alien mothership (Score:2)
Cosmic Beano required (Score:2)
So basically, we're dealing with astronomical objects farting.
Thank you, Doctor Science.
It's alive! (Score:2)
This thing was actually looking for its next space meal, but couldn't slow down enough to stop by Earth. Maybe next time.