Author Topic: Hyperbolic Hyperbole or Interstellar Interloper? ('Oumuamua)  (Read 72085 times)

Offline Star One

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Hyperbolic Hyperbole or Interstellar Interloper? ('Oumuamua)
« Reply #280 on: 12/13/2017 05:02 PM »
Decent summation of where we stand now with our knowledge of Oumuamua.

« Last Edit: 12/13/2017 05:02 PM by Star One »

Offline whitelancer64

Scanning for signs of technology:

https://www.theatlantic.com/science/archive/2017/12/yuri-milner-oumuamua-interstellar-asteroid/547985/

Probably wouldn't be a bad idea to point an x-ray telescope at this asteroid.  An IR check could also be useful, primarily to get an idea of stresses from its' tumbling.  Any chance of getting radar images of it, or is it too far out now?

It has already been observed in IR, by Spitzer. Hubble was also used for observations. It is currently farther from the Sun than Mars is, much too far for good radar data on it. Had we discovered it before its closest approach to Earth (which was still 24 million kilometers, 15 million miles away), we could have gotten some OK radar images of it.
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Offline Zed_Noir

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Re: Hyperbolic Hyperbole or Interstellar Interloper? ('Oumuamua)
« Reply #282 on: 12/14/2017 01:36 AM »
Decent summation of where we stand now with our knowledge of Oumuamua.



Doesn't rule anything out except that it is unlikely to be pile of stuff from accumulated space debris.




Online RotoSequence

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Re: Hyperbolic Hyperbole or Interstellar Interloper? ('Oumuamua)
« Reply #283 on: 12/14/2017 01:51 AM »
Space Time did an episode on Oumuamua  :)


Offline Dao Angkan

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Re: Hyperbolic Hyperbole or Interstellar Interloper? ('Oumuamua)
« Reply #284 on: 12/14/2017 07:15 PM »
Sky News in the UK had a live interview yesterday with one of the SETI guys at one of their observatories in the US. The presenter did a good job of asking sensible questions for what could be a sensationalist story, and the SETI guy did a good job of explaining what they're doing to the lay-person. There was even a discussion on the difference between METI and SETI (the presenter brought up that Stephen Hawking says that we should hide from ET), the SETI guy acknowledged that there is a big debate about this, but he falls on the "hide" side, and that SETI only listens.

It was a fun news piece (which is always welcome), whilst also showing science and astronomy in a good light. I don't know if SETI will ever find anything, but I think they do a good job of inspiring people and making space fun.

Online ncb1397

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Re: Hyperbolic Hyperbole or Interstellar Interloper? ('Oumuamua)
« Reply #285 on: 12/14/2017 08:09 PM »
Quote
Interstellar Visitor Stays Silent: No Signs of Life Yet on 'Oumuamua
https://www.space.com/39100-interstellar-object-oumuamua-alien-life-search.html?utm_source=notification

Probably not the best strategy to broadcast on the net when you will be listening if you want to pick something up from something that may not want you picking anything up. But any signals would likely be directional and thus this will probably only pick up anything if it was trying to make contact.
« Last Edit: 12/15/2017 03:30 AM by ncb1397 »

Offline Dao Angkan

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Re: Hyperbolic Hyperbole or Interstellar Interloper? ('Oumuamua)
« Reply #286 on: 12/14/2017 08:54 PM »
Quote
Interstellar Visitor Stays Silent: No Signs of Life Yet on 'Oumuamua
https://www.space.com/39100-interstellar-object-oumuamua-alien-life-search.html?utm_source=notification

Probably not the best strategy to broadcast on the net when you will be listening if you want to pick something up from something that may not want you pick anything up. But any signals would likely be directional and thus this will probably only pick up anything if it was trying to make contact.

So we can say that they're not METI at least! :)
« Last Edit: 12/14/2017 08:54 PM by Dao Angkan »

Offline JasonAW3

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Re: Hyperbolic Hyperbole or Interstellar Interloper? ('Oumuamua)
« Reply #287 on: 12/14/2017 11:31 PM »
Scanning for signs of technology:

https://www.theatlantic.com/science/archive/2017/12/yuri-milner-oumuamua-interstellar-asteroid/547985/

Probably wouldn't be a bad idea to point an x-ray telescope at this asteroid.  An IR check could also be useful, primarily to get an idea of stresses from its' tumbling.  Any chance of getting radar images of it, or is it too far out now?

It has already been observed in IR, by Spitzer. Hubble was also used for observations. It is currently farther from the Sun than Mars is, much too far for good radar data on it. Had we discovered it before its closest approach to Earth (which was still 24 million kilometers, 15 million miles away), we could have gotten some OK radar images of it.

This may seem slightly off topic, but it might not be a bad idea to orbit a few radio telescopes, maybe in the Earth - Moon Lagrange points, or possibly the solar Lagrange points.  A strong RF point source that could be used for long range radio mapping wouldn't be a bad idea as well.  Not only would they be useful for stellar observation, but useful for deep space observation of asteroids, comets, planets and other unusual objects.

      We could probably use inflatable structures for the telescopes, as this would provide the most structure for the least mass.
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Offline hop

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Re: Hyperbolic Hyperbole or Interstellar Interloper? ('Oumuamua)
« Reply #288 on: 12/16/2017 10:35 PM »
Karen Meech and collaborators secured additional HST time http://www.stsci.edu/cgi-bin/get-proposal-info?id=15447&observatory=HST

Quote
We request four additional HST/WFC3/UVIS orbits of 1I/217 U1 ('Oumuamua), our Solar System's first interstellar visitor, in order to complete our DD program 15405. Our science goal is to obtain precise astrometry along an extended arc length in order  to identify the region from which this object originated. Since the rotational light curve of 'Oumuamua shows variations of as much as 2.5 mag in brightness, a secure detection in the HST single exposures needed to maximize astrometric precision can only be assured in observations conducted at light curve maximum. However, we and other teams have recently determined that `Oumuamua is in a state of excited rotation and that, contrary to our intial expectations, we cannot predict the rotational phase in early January from existing data. We thus request four additional HST orbits that will allow us to sample `Oumuamua's light curve at multiple rotation phases, thereby ensuring that program 15405 will obtain a secure, final detection of our target that is crucial for this program to achieve its scientific objective.

Offline Star One

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Re: Hyperbolic Hyperbole or Interstellar Interloper? ('Oumuamua)
« Reply #289 on: 12/18/2017 03:52 PM »
Interstellar object ‘Oumuamua covered in 'thick crust of carbon-rich gunk

Quote
The mysterious interstellar object ‘Oumuamua that is shooting through our solar system is wrapped in a thick coating of carbon-rich gunk that built up on its cosmic travels, astronomers have found.

New observations of the cigar-shaped body found evidence for a deep surface layer that formed when organic ices – such as frozen carbon dioxide, methane and methanol – that make up the object were battered by the intense radiation that exists between the stars.

https://www.theguardian.com/science/2017/dec/18/interstellar-object-oumuamua-covered-in-thick-crust-of-carbon-rich-gunk

Offline jebbo

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Re: Hyperbolic Hyperbole or Interstellar Interloper? ('Oumuamua)
« Reply #290 on: 12/18/2017 04:26 PM »
The paper cited above:

Spectroscopy and thermal modelling of the first interstellar object 1I/2017 U1 ‘Oumuamua
Quote
During the formation and evolution of the Solar System, significant numbers of cometary and asteroidal bodies were ejected into interstellar space1,2. It is reasonable to expect that the same happened for planetary systems other than our own. Detection of such interstellar objects would allow us to probe the planetesimal formation processes around other stars, possibly together with the effects of long-term exposure to the interstellar medium. 1I/2017 U1 ‘Oumuamua is the first known interstellar object, discovered by the Pan-STARRS1 telescope in October 2017 (ref. 3). The discovery epoch photometry implies a highly elongated body with radii of ~ 200 × 20 m when a comet-like geometric albedo of 0.04 is assumed. The observable interstellar object population is expected to be dominated by comet-like bodies in agreement with our spectra, yet the reported inactivity of 'Oumuamua implies a lack of surface ice. Here, we report spectroscopic characterization of ‘Oumuamua, finding it to be variable with time but similar to organically rich surfaces found in the outer Solar System. We show that this is consistent with predictions of an insulating mantle produced by long-term cosmic ray exposure4. An internal icy composition cannot therefore be ruled out by the lack of activity, even though ‘Oumuamua passed within 0.25 au of the Sun.
https://www.nature.com/articles/s41550-017-0361-4?utm_content=bufferc0423&utm_medium=social&utm_source=twitter.com&utm_campaign=buffer

Offline Star One

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Hyperbolic Hyperbole or Interstellar Interloper? ('Oumuamua)
« Reply #291 on: 12/18/2017 04:52 PM »
An ideal habitat for basic life especially as that coating would probably protect it from the worst of interstellar radiation.

Quote
Fitzsimmons' team estimates that outer layer might have reached temperatures as high as 300 degrees Celsius during 'Oumuamua's closest pass of the sun, but that it would have provided enough insulation to prevent ice inside from vaporizing. Which raises the question: Could it have protected life inside the asteroid, perhaps waterborne microbes, from vaporizing as well?

I mean, technically? Yes. But Meech says that a far greater risk to microbial life would be the same cosmic rays that cooked 'Oumuamua's outside in the first place. Only if something were buried deep inside of the asteroid (say, at a distance of a few meters) would it be shielded from the harsh radiation of space.

https://www.wired.com/story/oumuamua-probably-isnt-a-spaceshipbut-it-could-have-passengers/
« Last Edit: 12/18/2017 05:18 PM by Star One »

Offline Mongo62

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Re: Hyperbolic Hyperbole or Interstellar Interloper? ('Oumuamua)
« Reply #292 on: 12/19/2017 01:01 AM »
On Distinguishing Interstellar Objects Like `Oumuamua From Products of Solar System Scattering

Schneider (2018) explored the possibility that 'Oumuamua is a Solar System object, and concluded that if it is, it must have been scattered by "another, yet unknown planet." I provide an extremely conservative upper limit on post-scattering velocities in the Solar System to show that 'Oumuamua is moving far to quickly to be the result of any hypothetical single scattering event between any bound Solar System objects within 21 au (a distance within which our understanding of objects capable of scattering 'Oumuamua is presumably complete).

Offline hop

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Offline Mongo62

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Re: Hyperbolic Hyperbole or Interstellar Interloper? ('Oumuamua)
« Reply #294 on: 12/20/2017 12:55 AM »
What and Whence 1I/`Oumuamua?

The first confirmed interstellar interloper in our Solar System, 1I/`Oumuamua, is likely to be a minor body ejected from another star, but its brief flyby and faintness made it difficult to study. Two remarkable properties are its large (2-2.5 mag) rotational variability and its motion relative to the Sun before encounter. The former suggests an extremely elongated (>10:1) shape and the latter an origin from the protoplanetary disk of a young star in a nearby association. 1I/`Oumuamua's variability can also be explained if it is a contact binary of near-equilibrium ellipsoidal components and heterogeneous surfaces, i.e. brighter, dust-mantled inner-facing hemispheres and darker, dust-free outer-facing poles. The probability that 1I/`Oumuamua has the same motion as a young stellar association is <1%. One explanation for the youth of 1I/`Oumuamua relative to the Solar neighborhood mean it that loss of dust mantles and darkening of lag surfaces by cosmic rays renders similar objects undetectable in a few 100's of Myr. In this scenario, 1I/`Oumuamua is smaller and much less massive, but represents a more numerous population of ejected planetesimals. Studies of such objects are a potential means to probe early planet formation, complementing observations of protoplanetary disks and studies of meteorites.

Offline Mongo62

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Re: Hyperbolic Hyperbole or Interstellar Interloper? ('Oumuamua)
« Reply #295 on: 12/21/2017 02:34 AM »
Ejection of material --"Jurads" -- from post main sequence planetary systems

We show that the rate of pollution of white dwarfs by asteroidal material implies a concomitant rate of material ejection that can contribute significantly to the population of interstellar minor bodies. We note also that the irradiation during post main sequence evolution implies that much of this ejected material may lose volatiles, providing a rationale for the curious properties of the recently discovered interstellar object Oumuamua.

Offline Ben the Space Brit

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Re: Hyperbolic Hyperbole or Interstellar Interloper? ('Oumuamua)
« Reply #296 on: 12/21/2017 08:56 AM »
Did I read that right? Basically, this suggestion is that Oumanuamua is basically a tiny solid bit of a planetary nebulae that has zipped by, aeons after being blown out of its home system by the dissolution of its primary?
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Offline vapour_nudge

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Re: Hyperbolic Hyperbole or Interstellar Interloper?
« Reply #297 on: 12/21/2017 09:33 AM »
I think that there has been a lot of unsupported speculation on this thread. What do we know for a fact about this object?

1. Definitely interstellar in origin, moving at close to the general velocity of gravitationally unbound objects in this part of the Galaxy.

2. There has been no obvious originating exoplanetary system found so far. There are a few possibilities, but all of them appear to have a low probability of being the originating system.

3. The reddish color slope of the object is consistent with an outer solar system object, either asteroidal or cometary. Its color is consistent with a variety of compositions, and in fact is exactly what would be expected for a dormant comet nucleus.

4. The shape derived from its light curve is highly unusual (but not unheard of) for a rocky asteroidal object, but comet nuclei have been found to frequently be quite elongated, although not as elongated as this object appears to be. A small sample size warning for comet nuclei, though.

5. Part of the light curve variations might be due to compositional differences, bringing its shape into the normal range.

6. Its rotation period of around 8 hours is not unusual, and is well over the limit for "rubble piles" of its size.

Conclusion: what we know of this object is consistent with a natural origin in the outer portions of an unidentified exoplanetary system.

Great post which is back to facts. I suspect the feelings of some are: "we can't prove it is not an alien created/manipulated object so it just might be".

It's hard to argue the point with those who just "want" to believe that stuff. We can't prove it isn't a giant dog - or a 1000x scale Tesla Roadster for that matter - but seeing the concise facts posted is great

I read an article recently and can't find it but it suggests the size is possibly a bit over 6:1 ratio now. Initial data suggested 10:1. It's great to see how the data is being refined. We live in exciting times; we don't need alien talk to make it exciting

Offline Star One

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Re: Hyperbolic Hyperbole or Interstellar Interloper? ('Oumuamua)
« Reply #298 on: 12/21/2017 11:07 AM »
I think that there has been a lot of unsupported speculation on this thread. What do we know for a fact about this object?

1. Definitely interstellar in origin, moving at close to the general velocity of gravitationally unbound objects in this part of the Galaxy.

2. There has been no obvious originating exoplanetary system found so far. There are a few possibilities, but all of them appear to have a low probability of being the originating system.

3. The reddish color slope of the object is consistent with an outer solar system object, either asteroidal or cometary. Its color is consistent with a variety of compositions, and in fact is exactly what would be expected for a dormant comet nucleus.

4. The shape derived from its light curve is highly unusual (but not unheard of) for a rocky asteroidal object, but comet nuclei have been found to frequently be quite elongated, although not as elongated as this object appears to be. A small sample size warning for comet nuclei, though.

5. Part of the light curve variations might be due to compositional differences, bringing its shape into the normal range.

6. Its rotation period of around 8 hours is not unusual, and is well over the limit for "rubble piles" of its size.

Conclusion: what we know of this object is consistent with a natural origin in the outer portions of an unidentified exoplanetary system.

Great post which is back to facts. I suspect the feelings of some are: "we can't prove it is not an alien created/manipulated object so it just might be".

It's hard to argue the point with those who just "want" to believe that stuff. We can't prove it isn't a giant dog - or a 1000x scale Tesla Roadster for that matter - but seeing the concise facts posted is great

I read an article recently and can't find it but it suggests the size is possibly a bit over 6:1 ratio now. Initial data suggested 10:1. It's great to see how the data is being refined. We live in exciting times; we don't need alien talk to make it exciting

Talk about making unrealistic comparisons to try and prove an argument. All that does it make your argument look weak and you’re not going to convince anyone that way.

Offline Mongo62

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Re: Hyperbolic Hyperbole or Interstellar Interloper? ('Oumuamua)
« Reply #299 on: 12/21/2017 02:41 PM »
Did I read that right? Basically, this suggestion is that Oumanuamua is basically a tiny solid bit of a planetary nebulae that has zipped by, aeons after being blown out of its home system by the dissolution of its primary?

The paper basically states that just as considerable asteroidal / cometary material is being regularly accreted by white dwarfs, other asteroidal / cometary material must be ejected, possibly comprising a significant fraction of all small interstellar objects.

Such material would have been baked by the preceding red giant phase for several million years, resulting in the sort of composition we see with 'Oumuamua.
« Last Edit: 12/21/2017 02:43 PM by Mongo62 »

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