Many anomalies of interstellar Oumuamua are explained if it was an alien solar sail

Telescopes could not get an image of the interstellar asteroid Oumuamua. Recent research shows that the asteroid had an acceleration. It deviated from a Keplerian orbit. It increased speed and changed direction. The deviation was with super-high statistical significance (30 standard deviations). Harvard researchers calculate that one explanation is that the asteroid was an alien solar sail.

Harvard researchers Bialy and Loeb offer a counter-explanation to the comet theory. If ‘Oumuamua were in fact a comet, why then did it not experience outgassing when it was closest to our Sun? In addition, they cite other research that showed that if outgassing were responsible for the acceleration, it would have also caused a rapid evolution in ‘Oumuamua’s spin (which was not observed).

They calculate that the movement is explained if was a light sail with sub-millimeter thickness.

If radiation pressure is the accelerating force, then ‘Oumuamua represents a new class of thin interstellar material, either produced naturally, through a yet unknown process in the ISM or in proto-planetary disks, or of an artificial origin.

Oumuamua entered the Solar System from north of the plane of the ecliptic. It had a speed of 26.35 km/s initially. It reached its maximum speed of 87.71 km/s (315,800 km/h) as it passed south of the ecliptic on 6 September and made a sharp turn upward at its closest approach to the Sun (perihelion) on 9 September at a distance of 0.255 AU (38,100,000 km; 23,700,000 mi) from the Sun. It was 17% closer than Mercury’s closest approach to the Sun. It headed away from the Sun towards Pegasus at an angle of 66° from the direction of its approach.

It was 240–1,000 meters long and 35 meters wide.

Accounting for Vega’s proper motion, it would have taken ʻOumuamua 600,000 years to reach the Solar System from Vega. But as a nearby star, Vega was not in the same part of the sky at that time.

Considering an artificial origin, one possibility is that ‘Oumuamua is a lightsail, floating in interstellar space as a debris from an advanced technological equipment. Lightsails with similar dimensions have been designed and constructed by our own civilization, including the IKAROS project and the Starshot Initiative.

This would account for the various anomalies of ‘Oumuamua, such as the unusual geometry inferred from its lightcurve, its low thermal emission, suggesting high reflectivity, and its deviation from a Keplerian orbit without any sign of a cometary tail or spin-up torques. Although ‘Oumuamua has a red surface color, similar to organic-rich surfaces of Solar-System comets and D-type asteroids, this does not contradict the artificial scenario, since irrespective of the object’s composition, as it travels through the ISM its surface will be covered by a layer of interstellar dust, which is itself composed of organic-rich materials.

Alternatively, a more exotic scenario is that ‘Oumuamua may be a fully operational probe sent intentionally to Earth vicinity by an alien civilization. Based on the PAN-STARRS survey characteristics, and assuming natural origins following random trajectories, Do et al. (2018) derived that the interstellar number density of ‘Oumuamua-like objects should be extremely high, ∼ 2×10^15 per cubic parsec, equivalent to ∼ 10 15 ejected planetisimals per star, and a factor of 100 to 100 million larger than predicted by theoretical models. This discrepancy is readily solved if ‘Oumuamua does not follow a random trajectory but is rather a targeted probe. Interestingly, ‘Oumuamua’s entry velocity is found to be extremely close to the velocity of the Local Standard of Rest, in a kinematic region that is occupied by less than 1 to 500 stars.

The observations of the interstellar asteroid were not sufficiently sensitive to provide a resolved image of ‘Oumuamua, and one can only speculate on its possible geometry and nature. Although periodic variations in the apparent magnitude are observed, there are still too many degrees of freedom (e.g., observing angle, non-uniform reflectively, etc.) to definitely constrain the geometry. The geometry should not necessarily be that of a planar sheet, but may acquire other shapes, e.g., involving a curved sheet, a hollow cone or ellipsoidal, etc. Depending on the geometry our estimated value for the mass-to-area ratio will change, but the correction is typically of order unity.

30 standard deviations away from normal orbit – certainty of anomalous acceleration

‘Oumuamua (1I/2017 U1) is the first object of interstellar origin observed in the Solar System. Recently, Micheli et al. (2018) reported that ‘Oumuamua showed deviations from a Keplerian orbit at a high statistical significance.

Nature – Non-gravitational acceleration in the trajectory of 1I/2017 U1 (‘Oumuamua)

Oumuamua (1I/2017 U1) is the first known object of interstellar origin to have entered the Solar System on an unbound and hyperbolic trajectory with respect to the Sun. Various physical observations collected during its visit to the Solar System showed that it has an unusually elongated shape and a tumbling rotation state. Micheli reported the detection, at 30σ significance, of non-gravitational acceleration in the motion of ‘Oumuamua.

A 20 sigma-event corresponds to an expected occurrence period measured in years that is 10 times larger than the higher of the estimates of the number of particles in the Universe. A 25-sigma event corresponds to an expected occurrence period that is equal to the higher of these estimates but with the decimal point moved 52 places to the left.

Solar sail as the reason

The observed trajectory is best explained by an excess radial acceleration ∆a ∝ r^−2, where r is the distance of ‘Oumuamua from the Sun. Such an acceleration is naturally expected for comets, driven by the evaporating material. However, recent observational and theoretical studies imply that ‘Oumuamua is not an active comet. they explore the possibility that the excess acceleration results from Solar radiation pressure. The required mass-to-area ratio is (m/A) ≈ 0.1 g cm−2. For a thin sheet this requires a width of ≈ 0.3−0.9 mm. We find that although extremely thin, such an object would survive an interstellar travel over Galactic distances of ∼ 5 kpc, withstanding collisions with gas and dust-grains as well as stresses from rotation and tidal forces. We discuss the possible origins of such an object including the possibility that it might be a lightsail of artificial origin. Our general results apply to any light probes designed for interstellar travel

Arxiv – Could Solar Radiation Pressure Explain ‘Oumuamua’s Peculiar Acceleration?

113 thoughts on “Many anomalies of interstellar Oumuamua are explained if it was an alien solar sail”

  1. I have ideas for both power production and satellite orbital changes. I would like to develop this into a business. I'm not a wealthy person. I'm an inventor with good ideas. And no way to develop them.

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  2. Only things we do know are: 1) It’s extra solar; 2) It has a strange light-curve (we know the shape of the light curve); 3) It has anomalous acceleration (we know the magnitude, direction, and duration of the acceleration); 4) No comet tail was detected.Everything else in inferred, including the cigar shape (inferred from light curve).

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  3. Only things we do know are: 1) It’s extra solar; 2) It has a strange light-curve (we know the shape of the light curve); 3) It has anomalous acceleration (we know the magnitude, direction, and duration of the acceleration); 4) No comet tail was detected.

    Everything else in inferred, including the cigar shape (inferred from light curve).

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  4. 1 for that. Good point about scale. The smallest creatures we know that can build complex structures are… ants and termites. (Though clearly their “intelligence” is a group effort.)But this could hold size and population of giant termite nests… let’s seeAbout 1 million termites in a 5x5x10 m termite mound. Say they are stacked around the circumference 100 m diameter = 314 m circumference = 63 mounds in the circumferencial ring, 5 m long.At 1000 m long that’s 200 rings, each with 314 mounds.Giving us 62 800 million termites could fit into that object.Of course they would want some space, for their agriculture. And they probably need some volume for the blacklight power generator and the emdrive… but you could very comfortably fit the population of the Earth in. If they were termite sized and lived in similar density.

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  5. Maybe a piece of a long-destroyed Dyson sphere satellite/statite set up around a class O star that went supernova? The inferred thickness is about right for a statite of a Pistol Star-like hypergiant, and a Dyson sphere around such a star could be so enormous that such a piece of debris would have a not-to-ridiculously-small chance of showing up in our nieghborhood even if the derbis were scattered evenly across the entire galactic disk.

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  6. First off I do not buy the solar sail crap. This seems to be a guess based upon a big unexplained occurrence. What is know is that it is extra solar and an abnormal cigar shaped asteroid and it accelerated which asteroids DO NOT do. The drawing of it is an artists rendition assuming it was a unusual rock. It is NOT a comet so out gassing is NOT the explanation for the acceleration. Yes this is an opportunity that should be explored and Space X Falcon Heavy could be used to launch an accelerated designed interceptor which should IMO allow for an interception at matched speeds.

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  7. +1 for that. Good point about scale. The smallest creatures we know that can build complex structures are… ants and termites. (Though clearly their “intelligence” is a group effort.)

    But this could hold size and population of giant termite nests… let’s see
    About 1 million termites in a 5x5x10 m termite mound. Say they are stacked around the circumference
    100 m diameter = 314 m circumference = 63 mounds in the circumferencial ring, 5 m long.

    At 1000 m long that’s 200 rings, each with 314 mounds.

    Giving us 62 800 million termites could fit into that object.

    Of course they would want some space, for their agriculture. And they probably need some volume for the blacklight power generator and the emdrive… but you could very comfortably fit the population of the Earth in. If they were termite sized and lived in similar density.

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  8. Somehow I think it would be creepier to find an alien probe and have the tech be understandable and already on our roadmap. If humans continue the way we are then sending probes off to stars will be standard affair for universities and the like. If we do catch an alien probe do we assume it is a pinnacle of their achievement or mere glimpse of their true abilities at the time of creation.

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  9. Maybe a piece of a long-destroyed Dyson sphere satellite/statite set up around a class O star that went supernova?

    The inferred thickness is about right for a statite of a Pistol Star-like hypergiant, and a Dyson sphere around such a star could be so enormous that such a piece of debris would have a not-to-ridiculously-small chance of showing up in our nieghborhood even if the derbis were scattered evenly across the entire galactic disk.

    Reply
  10. First off I do not buy the solar sail crap. This seems to be a guess based upon a big unexplained occurrence. What is know is that it is extra solar and an abnormal cigar shaped asteroid and it accelerated which asteroids DO NOT do. The drawing of it is an artists rendition assuming it was a unusual rock. It is NOT a comet so out gassing is NOT the explanation for the acceleration. Yes this is an opportunity that should be explored and Space X Falcon Heavy could be used to launch an accelerated designed interceptor which should IMO allow for an interception at matched speeds.

    Reply
  11. How pathetic of aliens to have to result in their using lame technology such as a solar sail! Ron Kita, Chiralex ..Gravity Modification. Dr Edward “H-Bomb” Teller looked for a connection between gravitation and electrets. Brilliant.

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  12. Somehow I think it would be creepier to find an alien probe and have the tech be understandable and already on our roadmap. If humans continue the way we are then sending probes off to stars will be standard affair for universities and the like. If we do catch an alien probe do we assume it is a pinnacle of their achievement or mere glimpse of their true abilities at the time of creation.

    Reply
  13. yes, I think ruled out, here from another paper by Micheli: Impulsive �� event. Models of the trajectory that include a single impulsive change invelocity, e.g., due to a collision , provide a poorer fit to the data (Table 1) than purely radialacceleration . More importantly, we see the non-gravitational signal even in disjoint subsets ofthe observed arc, separated at the time of the possible impulse, which makes continuousacceleration a far more likely explanation.very bizarre. I vote for alien ship or device. A very slow one.

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  14. The “breaking up a bit” wasen’t so much about just the removal of mass. It was about pockets of gas that would cause explosions when broken open. It is really just a variation on outgassing but where it is all coming from an edge that has broken.

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  15. The “Light bent by dust” hypotheses was not about gravity but refraction. Like when things change angles when you look through a glass of water. Get enough ice crystals…I don’t know. Gasses of different densities can also do this like desert mirages.

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  16. That elongatedshape is an extrapolation based on its changing albedo over time, not an actual fact.The same change in albedo could be seen if the object were a reflective disk scanning up and down as it spun around its axis, presenting a highly reflective surface to our point of view at differing angles as it collected snapshots of the local sights.As far as its change in speed, I wonder if it coincides with the “flyby effect” experienced by some of our space probes as they use the Earth for a gravity kick.Another possibility is that a smaller probe was ejected/decelerated in the opposite direction of Oumuamuas acceleration. If we knew the main mass, we could figure out how large a probe would need to be to have changed Oumuamuas speed to the degree it did.Yet another possibility is a powerful, focused transmission (laser?) of data back home, acting as an incidental thruster. Is there a target for such a beam that lay in the opposite direction of Oumuamuas acceleration?It could be an E-sail, rather than a solar sail. An E-sail uses a beam of particles to drain off the charge from the impacting solar wind. Stored up data could be transmitted in a concentrated burst of those bits and pieces.As far as a point of origin goes, it could be a probe or ejecta from a stellar flyby. Dozens of Sol-sized roaming stars have been identified as having made such close visits. And, far more, smaller, dimmer stars are sure to have made visits without our having ID’d them yet.One such visitor was only recently discovered. About 70,000 years ago a binary star system, Sholz’s Star, passed within 1ly (.82) of Sol. An object, probe, could have taken a double gravity assist to leave its system, made a swing around our ssystem, then headed out on an intercepting/return path to its mother, meeting up further down range.Its more likely to have come from somewhere close, as its moving at about the local speed. If our neighbouring stars were row boats on a smooth, slow moving river, we’d all be floating along together. If Oumuamua weas from somewhere “far, far away”, it would be like a speed boat slicing through our little fleet. But its more like just another row boat, slowly drifting by.Or… or, its a mass of ” itty-bitty” critters, reflective little buggers, joined up like an “ant raft” , scrambling over each other to catch the dusty yellow wind in spun silk sails, on a dead run back into the empty place.

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  17. How pathetic of aliens to have to result in their using lame technology such as a solar sail! Ron Kita, Chiralex ..Gravity Modification. Dr Edward “H-Bomb” Teller looked for a connection between gravitation and electrets. Brilliant.

    Reply
  18. Not really O’Neill cylinder scale. More oil tanker. So as an alien artifact not uncomparable in size to human vehicles (though, admittedly, not any of the ones we’ve got into space. Yet.)But interesting to a degree nearly impossible to exaggerate. First of all you’ve got the whole physical proof of aliens thing.Then you’ve got the overall amount of information that this provides about the aliens.- That they are space fairing (or at least were)- That they build large structures (or grow them?)- We might be able to work out what it actually did, or more likely have 1 million man-years of speculation, debate, argument and flame-wars on the subject.Finally there is detailed technological learning. Just about anything from a more advanced people (assuming that seeing as we can’t make something this big and send it between stars) would provide endless sources of education.The risk there is that it could be TOO advanced and we wouldn’t understand anything. Even there I think that some analogies are illustrative:A modern jet aircraft crashes into:- World War 2 – Most of it is intelligible. Advanced jet engine, wing and airframe design, but they could understand it (though recreating the alloys and materials could stop them taking full advantage). They wouldn’t get the electronics mostly, though if any were still functional they might learn something. – Victorian England – They would work out that it was a heavier than air flying machine. This ALONE would be a huge step because that concept itself was a major deal. They wouldn’t be able to recreate the engines but the turbine designs would feed into the preliminary work on steam and water turbines. The construction techniques would push their own work way ahead. They would learn all sorts of things about allen key bolts and rivet design and lightweight trusses bonded to stresses skins. The fact that many of the dead were FEMALE despite being dressed in scandalous male type clothing would be a surprise. Then someone copies the brassiere which was apparently not invented until bafflingly late in 1914. The zipper is a revelation. So are ball point pens.- Ancient Rome – As with the Victorians, a lot of the most immediately useful stuff would be things that we don’t associate with aircraft per se. Clothing design. Fasteners. Nuts and bolts. Rivets. Paper and pens. They probably don’t get the electrics at all unless they are still functional. Or even then. But hydraulics would make sense. They had pipes and taps for their water systems, now they see someone using it for controlled movement. And all the gears and cogs and mechanisms would show them new ways to do stuff. There are transparent glass windows… hey, this looks like the stuff we already make on a tiny scale.- Caveman – Oog see huge bird. Oog taste but not good to eat. Ogg take shiny things, very useful but Oog cannot make at all. Though this idea of making human have extra skin to keep warm… oog like.

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  19. Most of those possibilities would be almost as good to investigate as an actual alien artifact.So they are MORE reasons to send a probe.

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  20. But if it is a solar sail probe, then we know there wasn’t significant changes in course in deep space, so in that case we know what direction it came from.And it did NOT come from anywhere close enough to get here within decades. Or even centuries. Or millenia.If the aliens sent this deliberately in response to detecting Earth technology, it was the Velociraptor space program and T-rex based reality TV shows, not anything the little hairy scavengers in the trees did at the time.(After an even more advanced alien civilisation got their first seasons of Earth TV “Help, my daughter is marrying a T-rex!” they just dropped an asteroid on the place.)

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  21. yes, I think ruled out, here from another paper by Micheli:
    Impulsive �� event. Models of the trajectory that include a single impulsive change in
    velocity, e.g., due to a collision , provide a poorer fit to the data (Table 1) than purely radial
    acceleration . More importantly, we see the non-gravitational signal even in disjoint subsets of
    the observed arc, separated at the time of the possible impulse, which makes continuous
    acceleration a far more likely explanation.

    very bizarre. I vote for alien ship or device. A very slow one.

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  22. Yea, but why are we assuming any of this?If this were artificial, what is preventing it from being a Rama-style cylinder or anything else?

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  23. Rather than rely on unsubstantiated data and 4th hand stories, how about citing some sources? And I mean independently verifiable sources – not the stuff that some blogger or YouTuber claims. As the saying goes, extraordinary claims require extraordinary evidence.

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  24. Yes the shape made me think stage or drop tank on first report. If solar pressure its very lightweight who fit the tank or container type. Note that just an drop tank or some fairing would be idiotic interesting. Just the size would be O’Neill cylinder scale. And you only need an flyby if an artifact you find allocate budgets.

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  25. Buy try this here. Hint then your done your to burn to mars or Jupiter on an on an probe its pretty much an smart artillery shell, it can do corrections but not much more. Apollo 13 had to fly by the moon to get home, this is very obvious in KSP. Note that Apollo 13 had enough fuel to land on the Moon and get back up but not enough to speed up the time to get back significantly. Not an sponsored add and no responsibility if you get hooked.

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  26. Why an probe larger than any buildings we build? granted an giant telescope but an cigar.Read the paper, it assumes something like an fuel tank, think of an rocket stage or the shuttle drop tank, perhaps an container or fairing for an space station, huge and light weight so it affected by solar radiation, its also the most likely type of huge alien space junk we find.

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  27. The “breaking up a bit” wasen’t so much about just the removal of mass. It was about pockets of gas that would cause explosions when broken open. It is really just a variation on outgassing but where it is all coming from an edge that has broken.

    Reply
  28. The “Light bent by dust” hypotheses was not about gravity but refraction. Like when things change angles when you look through a glass of water. Get enough ice crystals…I don’t know. Gasses of different densities can also do this like desert mirages.

    Reply
  29. I don’t think it was coming from Vega. Apparently Vega is currently where the trajectory of the object passed through. Probably even further than Vega, my guess.Maybe it decelerated on the way in, may it’s observations and is now accelerating out?

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  30. Two questions-1. Can Parker change trajectory enough to be within a reasonable distance to image the object?More importantly-2. Is there anything on Parker, sensor wise, that will be suitable for inspecting the object?

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  31. That elongatedshape is an extrapolation based on its changing albedo over time, not an actual fact.

    The same change in albedo could be seen if the object were a reflective disk scanning up and down as it spun around its axis, presenting a highly reflective surface to our point of view at differing angles as it collected snapshots of the local sights.

    As far as its change in speed, I wonder if it coincides with the “flyby effect” experienced by some of our space probes as they use the Earth for a gravity kick.

    Another possibility is that a smaller probe was ejected/decelerated in the opposite direction of Oumuamuas acceleration. If we knew the main mass, we could figure out how large a probe would need to be to have changed Oumuamuas speed to the degree it did.

    Yet another possibility is a powerful, focused transmission (laser?) of data back home, acting as an incidental thruster. Is there a target for such a beam that lay in the opposite direction of Oumuamuas acceleration?

    It could be an E-sail, rather than a solar sail. An E-sail uses a beam of particles to drain off the charge from the impacting solar wind. Stored up data could be transmitted in a concentrated burst of those bits and pieces.

    As far as a point of origin goes, it could be a probe or ejecta from a stellar flyby. Dozens of Sol-sized roaming stars have been identified as having made such close visits. And, far more, smaller, dimmer stars are sure to have made visits without our having ID’d them yet.

    One such visitor was only recently discovered. About 70,000 years ago a binary star system, Sholz’s Star, passed within 1ly (.82) of Sol. An object, probe, could have taken a double gravity assist to leave its system, made a swing around our ssystem, then headed out on an intercepting/return path to its mother, meeting up further down range.

    Its more likely to have come from somewhere close, as its moving at about the local speed. If our neighbouring stars were row boats on a smooth, slow moving river, we’d all be floating along together. If Oumuamua weas from somewhere “far, far away”, it would be like a speed boat slicing through our little fleet. But its more like just another row boat, slowly drifting by.

    Or… or, its a mass of ” itty-bitty” critters, reflective little buggers, joined up like an “ant raft” , scrambling over each other to catch the dusty yellow wind in spun silk sails, on a dead run back into the empty place.

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  32. Parker Solar Probe will at some point be going 700,000 kph. That’s better than twice as fast. I say cut the solar mission short and go after the thing. At least we should have some payloads on standby in case such an opportunity arises again.

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  33. Provocative, to be sure. The SHAPE was provocative. Nothing like it ever has been observed amongst the hundreds-of-thousands of interplanetary and planet-bound objects we’ve been looking at since Galileo first cobbled together a telescope. Long, thin, needle shaped. 30 yards wide, 1,000 yards long. That’s one long-thin-needle. Faced with JUST that, physicists would have a darn difficult time coming up with a mehanism that would allow such a thing to either be created outright, or start more spherical and be chipped away to just the long thin core. Nothing seems plausible. That it is also tumbling end-over-end is somewhat less problematic. Centripetal force definitely would keep the thing from losing anything accreting to it. At least with some confidence we can say it ain’t a dust-covered cigar.Now, add the anomalous acceleration. Physicists are having conniptions over this one in the ‘space of concepts’ limited by its odd shape. It isn’t very clear from the article(s) where most of the acceleration(s) were measured. One presumes “closer to Earth” of course, but were they really solar-energy related?Anyway, its all quite provocative. GoatGuy

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  34. … somewhat worse … is also that it is going so slowly. As the article say, it’d take 500,000+ years to get to Vega. Or from it. That’s a long time. Maybe nothing much for machines, but for animals, a long time. GoatGuy

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  35. The LIKELIHOOD of it bumping into another solar rock (just happening to be heading out … in the same direction… to hit it in the âhrse, to accelerate it forward, faster) is pretty small. Perhaps similar to a pair of blind gunmen shooting at each other, a thousand yards apart, in the high desert. Remember, they’re blind. Odds are pretty good that neither will hit the other, even if helpers for both turn them to face “more or less” the right direction. ±5° left-right. ±10° up-down. (⁵⁄₃₆₀ × 2π) • (¹⁰⁄₃₆₀ × 2π) = 0.0152 radian²(1000 yard × 3 ft)² × 0.0152 = 137,000 ft²A person probably has a frontal area of 12 ft². 137,000 ÷ 12 = 1 in 12,000Actually the odds of being hit by a piece of outward rushing space junk is far worse than that. The gunmen are at least TRYING to aim blindly at each other, with helpers too. GoatGuy

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  36. ⇒ area of debris…True, although there would also be a field of collision debris in its wake. Now, whether we could detect that debris from here or not is an entirely different matter. Its hard enough to try to image volkswagon sized chunks hitting the face of the moon. ⇒ outgassingYah, could be that, and in fact remains likely. Only problem is, that the usual cometary outgassing evidence isn’t being observed. Wasn’t at closest solar approach, wasn’t on the way out of Dodge, and isn’t at present. ⇒ breaking up a bityes, but no. Spin up a rod and whack off one end while spinning; what happens? The rod accelerates a tiny bit opposite the direction of the lost tip. But compared to the whole, not that very much. For something as large as Oumuamua, the ‘lost tip’ wouldn’t have a velocity higher than a few meters per second. ⇒ Forces we don’t know about yetPerhaps. Most of physics doesn’t think that that’s likely. With the exception of a few theories that postulate the so-called Newtonian gravitational forces vary from 1/R² at great distances to 1/R … to explain dark matter and dark energy, except for that everyone else thinks that gravitation happily remains 1/R² at all distances from all masses. ⇒ Light bent by dust.Nope. Nowhere near enough gravitational pull for that. The “dust” would have to be made out of condensed dark matter. ⇒ Electron-proton balance.Nope. Passing by the Sun, it would have picked up however many extra electrons or protons to balance out charge. It is a highly conserved attraction. ________________________________________The point is the acceleration change was an ACCELERATION change. It has increased in speed, which is quite anomalous. Retarding could be relatively straight-forward explained by physics. Acceleration isn’t so easily handled without interaction with a large intense force. ⇒ Human errorPerhaps. We’re pretty good at astrometry though. Just saying,GoatGuy

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  37. No, probably closer to “hey so we have really high certainty that it is behaving like a comet, but until we actually prove it, it is being described as an astonishingly out-of-the-ordinary asteroid”

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  38. Not really O’Neill cylinder scale. More oil tanker. So as an alien artifact not uncomparable in size to human vehicles (though, admittedly, not any of the ones we’ve got into space. Yet.)

    But interesting to a degree nearly impossible to exaggerate.

    First of all you’ve got the whole physical proof of aliens thing.

    Then you’ve got the overall amount of information that this provides about the aliens.
    – That they are space fairing (or at least were)
    – That they build large structures (or grow them?)
    – We might be able to work out what it actually did, or more likely have 1 million man-years of speculation, debate, argument and flame-wars on the subject.

    Finally there is detailed technological learning. Just about anything from a more advanced people (assuming that seeing as we can’t make something this big and send it between stars) would provide endless sources of education.

    The risk there is that it could be TOO advanced and we wouldn’t understand anything. Even there I think that some analogies are illustrative:

    A modern jet aircraft crashes into:
    – World War 2 – Most of it is intelligible. Advanced jet engine, wing and airframe design, but they could understand it (though recreating the alloys and materials could stop them taking full advantage). They wouldn’t get the electronics mostly, though if any were still functional they might learn something.
    – Victorian England – They would work out that it was a heavier than air flying machine. This ALONE would be a huge step because that concept itself was a major deal. They wouldn’t be able to recreate the engines but the turbine designs would feed into the preliminary work on steam and water turbines. The construction techniques would push their own work way ahead. They would learn all sorts of things about allen key bolts and rivet design and lightweight trusses bonded to stresses skins. The fact that many of the dead were FEMALE despite being dressed in scandalous male type clothing would be a surprise. Then someone copies the brassiere which was apparently not invented until bafflingly late in 1914. The zipper is a revelation. So are ball point pens.
    – Ancient Rome – As with the Victorians, a lot of the most immediately useful stuff would be things that we don’t associate with aircraft per se. Clothing design. Fasteners. Nuts and bolts. Rivets. Paper and pens. They probably don’t get the electrics at all unless they are still functional. Or even then. But hydraulics would make sense. They had pipes and taps for their water systems, now they see someone using it for controlled movement. And all the gears and cogs and mechanisms would show them new ways to do stuff. There are transparent glass windows… hey, this looks like the stuff we already make on a tiny scale.
    – Caveman – Oog see huge bird. Oog taste but not good to eat. Ogg take shiny things, very useful but Oog cannot make at all. Though this idea of making human have extra skin to keep warm… oog like.

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  39. I didn’t realize Oumuamua was so controversial.In hindsight, they should have named it Rama and arrange for a probe to rendezvous with it for a closer look.

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  40. But if it is a solar sail probe, then we know there wasn’t significant changes in course in deep space, so in that case we know what direction it came from.
    And it did NOT come from anywhere close enough to get here within decades. Or even centuries. Or millenia.

    If the aliens sent this deliberately in response to detecting Earth technology, it was the Velociraptor space program and T-rex based reality TV shows, not anything the little hairy scavengers in the trees did at the time.

    (After an even more advanced alien civilisation got their first seasons of Earth TV “Help, my daughter is marrying a T-rex!” they just dropped an asteroid on the place.)

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  41. So, if we look back along its trajectory, is there a nearby star, where it could have either launched or done another gravitational assist?

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  42. I thought it was well established that ‘Oumuamua is spindle-shaped, or in any case much longer in one direction than in the other two. That is an extremely ungainly shape for a solar sail.

    Reply
  43. Am I reading this wrong? 30 sigma for anomalous acceleration that isn’t explained through the normal means, but then the paper starts its concluding paragraph with this: “Outgassing provides the most plausible physical model of the non-gravitational acceleration by postulating that ‘Oumuamua behaves like a miniature comet”.So it’s not a comet but it has to be? Or is this just a catch-all way of saying, “hey, so we have really high certainty that it doesn’t behave like a comet, but until we can actually prove it, it’s a comet”?

    Reply
  44. Yes the shape made me think stage or drop tank on first report. If solar pressure its very lightweight who fit the tank or container type.
    Note that just an drop tank or some fairing would be idiotic interesting. Just the size would be O’Neill cylinder scale. And you only need an flyby if an artifact you find allocate budgets.

    Reply
  45. Buy https://www.kerbalspaceprogram.com/en/
    try this here. Hint then your done your to burn to mars or Jupiter on an on an probe its pretty much an smart artillery shell, it can do corrections but not much more. Apollo 13 had to fly by the moon to get home, this is very obvious in KSP. Note that Apollo 13 had enough fuel to land on the Moon and get back up but not enough to speed up the time to get back significantly.
    Not an sponsored add and no responsibility if you get hooked.

    Reply
  46. Why an probe larger than any buildings we build? granted an giant telescope but an cigar.
    Read the paper, it assumes something like an fuel tank, think of an rocket stage or the shuttle drop tank, perhaps an container or fairing for an space station, huge and light weight so it affected by solar radiation, its also the most likely type of huge alien space junk we find.

    Reply
  47. I don’t think it was coming from Vega. Apparently Vega is currently where the trajectory of the object passed through. Probably even further than Vega, my guess.
    Maybe it decelerated on the way in, may it’s observations and is now accelerating out?

    Reply
  48. Two questions-
    1. Can Parker change trajectory enough to be within a reasonable distance to image the object?
    More importantly-
    2. Is there anything on Parker, sensor wise, that will be suitable for inspecting the object?

    Reply
  49. There are plenty of normal explanations before jumping to modern mythology. Impact with smaller asteroids, perhaps it went through an area where two objects hit each other and left a field of debris. Hitting that residue could easily change the trajectory, or it could be out-gassing, it could even have broken up a little and just minor gas pressures within were sufficient to change the trajectory, there could even be a heavy, but invisible to our telescopes, object it gravitationally interacted with. There could be some natural force related to entering a solar system we don’t know anything about…some minor space curvature or something. The light could be bent just by differing amounts of dust. Maybe in other solar systems there is a slightly different electron to proton balance and there is some crazy static electrical thing going on. That could make it suck up dust spit out dust or just have interactions similar to gravity. Or there could have been a technical error/human error. That is a lot of stuff to rule out, and there are probably other possibilities I haven’t thought of. There are just so many possibilities.

    Reply
  50. Or, another rock, undetected, bumped into it. Or, its a old alien spaceship, adrift and venting fuel now and then. For the nerdy, here is a good paper about it: Non-Gravitational Acceleration in theTrajectory of 1I/2017 U1, Micheli et al.

    Reply
  51. I’m impressed that two members of a supposed stuffy Ivy League school offer this theory. It means that there are ‘open minds’ at several levels. The authors kept their supposition scientific, and their speculation to a minimum. Having said that, it does seem a stretch – a shame we couldn’t turn Hubble on the object to get a much better look at it…still at this point – more questions than answers.

    Reply
  52. Personally, I hope it’s not a solar sail simply because if it is, that all but guarantees that FTL isn’t possible and we’re stuck to this star. On the off chance it did come from a celestial neighbor, that would imply they’re close enough to have sent one in the past few decades, presumably after detecting the changes to our atmospheric makeup. If that’s the case, it’ll be years before any photos of the Earth are sent back to wherever they are, and another few decades before another would be sent to make contact. In such a situation, it would make sense to send a prove that would move slower and could enter orbit. Perhaps these aliens would be different, but if humans found alien life on another world, the space program would get all the finding it could dream of for a few years. I guess we’ll see if they say hello in fifty years or so.

    Reply
  53. Wait- so we have positively confirmed any and all methods that alien civilizations use for travel….? And their existence as well? When did I miss THAT news?Care to explain the tone of your statement, because it certainly implies that.

    Reply
  54. Parker Solar Probe will at some point be going 700,000 kph. That’s better than twice as fast. I say cut the solar mission short and go after the thing. At least we should have some payloads on standby in case such an opportunity arises again.

    Reply
  55. Provocative, to be sure.

    The SHAPE was provocative. Nothing like it ever has been observed amongst the hundreds-of-thousands of interplanetary and planet-bound objects we’ve been looking at since Galileo first cobbled together a telescope. Long, thin, needle shaped. 30 yards wide, 1,000 yards long. That’s one long-thin-needle.

    Faced with JUST that, physicists would have a darn difficult time coming up with a mehanism that would allow such a thing to either be created outright, or start more spherical and be chipped away to just the long thin core. Nothing seems plausible. That it is also tumbling end-over-end is somewhat less problematic. Centripetal force definitely would keep the thing from losing anything accreting to it. At least with some confidence we can say it ain’t a dust-covered cigar.

    Now, add the anomalous acceleration.

    Physicists are having conniptions over this one in the ‘space of concepts’ limited by its odd shape. It isn’t very clear from the article(s) where most of the acceleration(s) were measured. One presumes “closer to Earth” of course, but were they really solar-energy related?

    Anyway, its all quite provocative.

    GoatGuy

    Reply
  56. Solar sail would work well for small and light probes, not for something far larger than an supertanker. That is unless the sail is planet sized. Also oumuamua moves way to slow to be an alien probe but fitting for something ejected from an star

    Reply
  57. … somewhat worse … is also that it is going so slowly.

    As the article say, it’d take 500,000+ years to get to Vega. Or from it. That’s a long time. Maybe nothing much for machines, but for animals, a long time.

    GoatGuy

    Reply
  58. The LIKELIHOOD of it bumping into another solar rock (just happening to be heading out … in the same direction… to hit it in the âhrse, to accelerate it forward, faster) is pretty small. Perhaps similar to a pair of blind gunmen shooting at each other, a thousand yards apart, in the high desert. Remember, they’re blind. Odds are pretty good that neither will hit the other, even if helpers for both turn them to face “more or less” the right direction.

    ±5° left-right. ±10° up-down.

    (⁵⁄₃₆₀ × 2π) • (¹⁰⁄₃₆₀ × 2π) = 0.0152 radian²
    (1000 yard × 3 ft)² × 0.0152 = 137,000 ft²

    A person probably has a frontal area of 12 ft².

    137,000 ÷ 12 = 1 in 12,000

    Actually the odds of being hit by a piece of outward rushing space junk is far worse than that. The gunmen are at least TRYING to aim blindly at each other, with helpers too.

    GoatGuy

    Reply
  59. ⇒ area of debris…

    True, although there would also be a field of collision debris in its wake. Now, whether we could detect that debris from here or not is an entirely different matter. Its hard enough to try to image volkswagon sized chunks hitting the face of the moon.

    ⇒ outgassing

    Yah, could be that, and in fact remains likely. Only problem is, that the usual cometary outgassing evidence isn’t being observed. Wasn’t at closest solar approach, wasn’t on the way out of Dodge, and isn’t at present.

    ⇒ breaking up a bit

    yes, but no. Spin up a rod and whack off one end while spinning; what happens? The rod accelerates a tiny bit opposite the direction of the lost tip. But compared to the whole, not that very much. For something as large as Oumuamua, the ‘lost tip’ wouldn’t have a velocity higher than a few meters per second.

    ⇒ Forces we don’t know about yet

    Perhaps. Most of physics doesn’t think that that’s likely. With the exception of a few theories that postulate the so-called Newtonian gravitational forces vary from 1/R² at great distances to 1/R … to explain dark matter and dark energy, except for that everyone else thinks that gravitation happily remains 1/R² at all distances from all masses.

    ⇒ Light bent by dust.

    Nope. Nowhere near enough gravitational pull for that. The “dust” would have to be made out of condensed dark matter.

    ⇒ Electron-proton balance.

    Nope. Passing by the Sun, it would have picked up however many extra electrons or protons to balance out charge. It is a highly conserved attraction.
    ________________________________________

    The point is the acceleration change was an ACCELERATION change. It has increased in speed, which is quite anomalous. Retarding could be relatively straight-forward explained by physics. Acceleration isn’t so easily handled without interaction with a large intense force.

    ⇒ Human error

    Perhaps. We’re pretty good at astrometry though.

    Just saying,
    GoatGuy

    Reply
  60. No, probably closer to “hey so we have really high certainty that it is behaving like a comet, but until we actually prove it, it is being described as an astonishingly out-of-the-ordinary asteroid”

    Reply
  61. Outgassing still seems like the most plausible explanation. Perhaps passing the sun heated it up enough to have a delayed outgassing. Perhaps the reason it is tumbling is because of previous outgassing from the same crack and it is already spinning around that axis, so any further outgassing might not result in seemingly random torque.

    Reply
  62. If we look at our civilization az it’s current state, we do not yet have FTL capabilities, but we made the first steps with solar sails and have a project aiming other stars (StarShot, if I recall it’s name well). So in a similar case another technical civilization could have sent such a probe (allowing, that later they developed further to higher levels, leaving the solar sail era).

    Reply
  63. Am I reading this wrong? 30 sigma for anomalous acceleration that isn’t explained through the normal means, but then the paper starts its concluding paragraph with this:

    “Outgassing provides the most plausible physical model of the non-gravitational acceleration by postulating that ‘Oumuamua behaves like a miniature comet”.

    So it’s not a comet but it has to be? Or is this just a catch-all way of saying, “hey, so we have really high certainty that it doesn’t behave like a comet, but until we can actually prove it, it’s a comet”?

    Reply
  64. Aliens don’t use solar sails. That would be ridiculous for them regarding the far away planets they are coming from. They are multi dimensional beings and their vehicles although equipped with very advanced propulsion systems, also allows them to reach any point in the universe almost instantaneously.

    Reply
  65. There are plenty of normal explanations before jumping to modern mythology. Impact with smaller asteroids, perhaps it went through an area where two objects hit each other and left a field of debris. Hitting that residue could easily change the trajectory, or it could be out-gassing, it could even have broken up a little and just minor gas pressures within were sufficient to change the trajectory, there could even be a heavy, but invisible to our telescopes, object it gravitationally interacted with. There could be some natural force related to entering a solar system we don’t know anything about…some minor space curvature or something. The light could be bent just by differing amounts of dust. Maybe in other solar systems there is a slightly different electron to proton balance and there is some crazy static electrical thing going on. That could make it suck up dust spit out dust or just have interactions similar to gravity. Or there could have been a technical error/human error. That is a lot of stuff to rule out, and there are probably other possibilities I haven’t thought of. There are just so many possibilities.

    Reply
  66. Or, another rock, undetected, bumped into it. Or, its a old alien spaceship, adrift and venting fuel now and then. For the nerdy, here is a good paper about it: Non-Gravitational Acceleration in the
    Trajectory of 1I/2017 U1, Micheli et al.

    Reply
  67. I’m impressed that two members of a supposed stuffy Ivy League school offer this theory. It means that there are ‘open minds’ at several levels. The authors kept their supposition scientific, and their speculation to a minimum. Having said that, it does seem a stretch – a shame we couldn’t turn Hubble on the object to get a much better look at it…still at this point – more questions than answers.

    Reply
  68. Solar sail would work well for small and light probes, not for something far larger than an supertanker.
    That is unless the sail is planet sized.
    Also oumuamua moves way to slow to be an alien probe but fitting for something ejected from an star

    Reply
  69. Outgassing still seems like the most plausible explanation. Perhaps passing the sun heated it up enough to have a delayed outgassing. Perhaps the reason it is tumbling is because of previous outgassing from the same crack and it is already spinning around that axis, so any further outgassing might not result in seemingly random torque.

    Reply
  70. Aliens don’t use solar sails. That would be ridiculous for them regarding the far away planets they are coming from. They are multi dimensional beings and their vehicles although equipped with very advanced propulsion systems, also allows them to reach any point in the universe almost instantaneously.

    Reply

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