Author Topic: Hyperbolic Hyperbole or Interstellar Interloper? ('Oumuamua)  (Read 79123 times)

Offline Star One

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Re: Hyperbolic Hyperbole or Interstellar Interloper? ('Oumuamua)
« Reply #400 on: 11/15/2018 10:23 pm »
Does it bother anyone else that the outgassing hypothesis is treated as such an open and shut thing in this press release, given the inconsistencies in Oumuamua's solar encounter dynamics when compared to cometary behavior?

Yes I agree.

Offline mcgyver

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Re: Hyperbolic Hyperbole or Interstellar Interloper? ('Oumuamua)
« Reply #401 on: 11/16/2018 10:18 am »
Does it bother anyone else that the outgassing hypothesis is treated as such an open and shut thing in this press release, given the inconsistencies in Oumuamua's solar encounter dynamics when compared to cometary behavior?
sudden, short and unique explosion/sublimation of an underground ice block due to solar heating?

Online Zed_Noir

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Re: Hyperbolic Hyperbole or Interstellar Interloper? ('Oumuamua)
« Reply #402 on: 11/16/2018 11:31 am »
Does it bother anyone else that the outgassing hypothesis is treated as such an open and shut thing in this press release, given the inconsistencies in Oumuamua's solar encounter dynamics when compared to cometary behavior?
sudden, short and unique explosion/sublimation of an underground ice block due to solar heating?

That should be at the closest approach to the sun. If there is any water that is not sublime away during inbound approach.

But I am not aware of any reports of significant out gassing of either volatiles or dust.

Offline mcgyver

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Re: Hyperbolic Hyperbole or Interstellar Interloper? ('Oumuamua)
« Reply #403 on: 11/16/2018 12:11 pm »

But I am not aware of any reports of significant out gassing of either volatiles or dust.
That's why I assumed "sudden and short", like a bubble exploding.
Anyway, without further data, it could have been anything.
Could it even be an error in measuring or calculating? 0.00000492 meter/s2  on a body 800 meters long and some billions meters away.
Or is the datum confirmed?




Offline Bynaus

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Re: Hyperbolic Hyperbole or Interstellar Interloper? ('Oumuamua)
« Reply #404 on: 11/16/2018 12:51 pm »
A sudden blow would have affected the orbit in a different way - what was observed was a constant shift, as if a force, roughly proportional to the inverse of the distance to the Sun squared, was acting on the object. So no, a sudden blow can't explain the orbit.

Its quite remarkable that even if we assume that the CO, CO2, dust emissions are at their upper limit (by no way a given), this would require the water to CO, CO2 ratio in the comet to be much higher than in solar system comets (if water evaporating is the reason for the push). Sure, you can construct a scenario where CO, CO2 evaporates first, so that water evaporates on the outgoing leg of the hyperbolic orbit, but it just sounds so... constructed. We really don't understand this object.
More of my thoughts: www.final-frontier.ch (in German)

Offline MoonMoon

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Re: Hyperbolic Hyperbole or Interstellar Interloper? ('Oumuamua)
« Reply #405 on: 11/16/2018 08:19 pm »
Would it be possible for ETI beings to design a craft that appears to be tumbling and outgassing? Better yet why not design a probe that is meant to be studied or captured? Why not send your tech out there like we have with gold records and dvds? I’m not a believer in the whole “we are being visited on purpose” but I do believe a probe with AI can exist out there. This conversation needs to be welcomed amongst us average folks and scientific community.
extraordinary blah blah blah requires extraordinary blah blah blah

Online John-H

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Re: Hyperbolic Hyperbole or Interstellar Interloper? ('Oumuamua)
« Reply #406 on: 11/16/2018 10:34 pm »
This is the first object we have seen that has not been touched by any sunlight for a long, long time. Do we have any measurement of how big, or how heavy, it is except for the amount of light reflected? Could it be much smaller and shinier, or much less dense than a normal asteroid, and could it thus be much more affected by radiation pressure?  Perhaps it is a very light collection of hoar frost particles.

John

Offline hop

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Re: Hyperbolic Hyperbole or Interstellar Interloper? ('Oumuamua)
« Reply #407 on: 11/17/2018 02:49 am »
This is the first object we have seen that has not been touched by any sunlight for a long, long time.
Oort cloud comets can have periods in the millions of years range, and many likely spend far longer beyond at tens of thousands of AU before they get nudged into the planetary region. That kind of distances shouldn't be terribly different from the larger interstellar environment.

Quote
Do we have any measurement of how big, or how heavy, it is except for the amount of light reflected? Could it be much smaller and shinier, or much less dense than a normal asteroid, and could it thus be much more affected by radiation pressure? 
Not really. The size, density and albedo are very much open questions. Papers have argued that various observations point toward various values, but there are generally a lot of unverifiable assumptions involved.

Online ugordan

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Re: Hyperbolic Hyperbole or Interstellar Interloper? ('Oumuamua)
« Reply #408 on: 11/21/2018 05:52 pm »

Offline Star One

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Re: Hyperbolic Hyperbole or Interstellar Interloper? ('Oumuamua)
« Reply #409 on: 01/14/2019 08:32 pm »
Harvard Astronomer Defends Hypothesis That Object Is Alien Probe

Quote
In a new interview with the Israeli newspaper Haaretz, the chair of Harvard University’s Astronomy Department Avi Loeb defended his controversial hypothesis that the interstellar object known as ‘Oumuamua could be an alien probe — and speculated at length about the place of humanity in the cosmos.

“As soon as we leave the solar system, I believe we will see a great deal of traffic out there,” he told Haaretz. “Possibly we’ll get a message that says, ‘Welcome to the interstellar club.’ Or we’ll discover multiple dead civilizations — that is, we’ll find their remains.”

Offline Star One

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Hyperbolic Hyperbole or Interstellar Interloper? ('Oumuamua)
« Reply #410 on: 01/21/2019 08:05 pm »
Further to the above Jason Wright writes in defence of Avi Loeb. But really he is more defending SETI research.

https://www.centauri-dreams.org/2019/01/21/oumuamua-seti-and-the-media/
« Last Edit: 01/21/2019 08:21 pm by Star One »

Offline Torbjorn Larsson, OM

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Re: Hyperbolic Hyperbole or Interstellar Interloper? ('Oumuamua)
« Reply #411 on: 01/22/2019 01:35 pm »
Much as I appreciate the astrobiology - and other - papers of Loeb, and his risk attitude towards recognition for his more speculative ideas, this does not merit defense. It is just a low likelihood, non-competitive, forgettable idea.

Does it bother anyone else that the outgassing hypothesis is treated as such an open and shut thing in this press release, given the inconsistencies in Oumuamua's solar encounter dynamics when compared to cometary behavior?

No, it would be prior consistent with astrophysics - low likelihood for something new - and astrobiology - low frequency for language capable life - both. And the new high likelihood posterior among the low likelihood hypotheses converts that to a "shut case" as far as observation goes - it *was* outgassing, added to a low mass to push around.

Offline Star One

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Re: Hyperbolic Hyperbole or Interstellar Interloper? ('Oumuamua)
« Reply #412 on: 01/22/2019 04:19 pm »
Much as I appreciate the astrobiology - and other - papers of Loeb, and his risk attitude towards recognition for his more speculative ideas, this does not merit defense. It is just a low likelihood, non-competitive, forgettable idea.

Does it bother anyone else that the outgassing hypothesis is treated as such an open and shut thing in this press release, given the inconsistencies in Oumuamua's solar encounter dynamics when compared to cometary behavior?

No, it would be prior consistent with astrophysics - low likelihood for something new - and astrobiology - low frequency for language capable life - both. And the new high likelihood posterior among the low likelihood hypotheses converts that to a "shut case" as far as observation goes - it *was* outgassing, added to a low mass to push around.

As I said above Wright is more defending the idea of SETI than Loeb himself, he’s more of a convenient springboard for his ideas.

Offline Star One

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Re: Hyperbolic Hyperbole or Interstellar Interloper? ('Oumuamua)
« Reply #413 on: 02/18/2019 03:32 pm »
Good article from Phil Plait on the latest theory concerning Oumuamua.

https://www.syfy.com/syfywire/no-oumuamua-is-not-an-alien-spaceship-it-might-be-even-weirder

Offline Mongo62

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Re: Hyperbolic Hyperbole or Interstellar Interloper? ('Oumuamua)
« Reply #414 on: 03/01/2019 02:33 pm »
Good article from Phil Plait on the latest theory concerning Oumuamua.

https://www.syfy.com/syfywire/no-oumuamua-is-not-an-alien-spaceship-it-might-be-even-weirder

Anton Petrov has a video out regarding ths hypothesis:


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