Please create an account to participate in the Slashdot moderation system

 



Forgot your password?
typodupeerror
×
Space Science

Have Aliens Found Us? A Harvard Astronomer on the Mysterious Interstellar Object 'Oumuamua (newyorker.com) 583

On October 19, 2017, astronomers at the University of Hawaii spotted a strange object travelling through our solar system, which they later described as "a red and extremely elongated asteroid." It was the first interstellar object to be detected within our solar system; the scientists named it 'Oumuamua, the Hawaiian word for a scout or messenger. The following October, Avi Loeb, the chair of Harvard's astronomy department, co-wrote a paper (with a Harvard postdoctoral fellow, Shmuel Bialy) that examined 'Oumuamua's "peculiar acceleration" and suggested that the object "may be a fully operational probe sent intentionally to Earth's vicinity by an alien civilization." Loeb has long been interested in the search for extraterrestrial life, and he recently made further headlines by suggesting that we might communicate with the civilization that sent the probe.

Isaac Chotiner of The New Yorker has interviewed Loeb, who was frustrated that scientists saw 'Oumuamua too late in its journey to photograph the object. "My motivation for writing the paper is to alert the community to pay a lot more attention to the next visitor," he told Chotiner. An excerpt from the interview: The New Yorker: Your explanation of why 'Oumuamua might be an interstellar probe may be hard for laypeople to understand. Why might this be the case, beyond the fact that lots of things are possible?
Loeb: There is a Scientific American article I wrote where I summarized six strange facts about 'Oumuamua. The first one is that we didn't expect this object to exist in the first place. We see the solar system and we can calculate at what rate it ejected rocks during its history. And if we assume all planetary systems around other stars are doing the same thing, we can figure out what the population of interstellar objects should be. That calculation results in a lot of possibilities, but the range is much less than needed to explain the discovery of 'Oumuamua.
There is another peculiar fact about this object. When you look at all the stars in the vicinity of the sun, they move relative to the sun, the sun moves relative to them, but only one in five hundred stars in that frame is moving as slow as 'Oumuamua. You would expect that most rocks would move roughly at the speed of the star they came from. If this object came from another star, that star would have to be very special.

[...]The New Yorker: Hold on. "'Not where is the lack of evidence so that I can fit in any hypothesis that I like?' " [Bailer-Jones, of the Max Planck Institute for Astronomy, in Heidelberg, Germany, has identified four possible home stars for 'Oumuamua, and was asked to respond to Loeb's light-sail theory by NBC.]
Loeb: Well, it's exactly the approach that I took. I approached this with a scientific mind, like I approach any other problem in astronomy or science that I work on. The point is that we follow the evidence, and the evidence in this particular case is that there are six peculiar facts. And one of these facts is that it deviated from an orbit shaped by gravity while not showing any of the telltale signs of cometary outgassing activity. So we don't see the gas around it, we don't see the cometary tail. It has an extreme shape that we have never seen before in either asteroids or comets. We know that we couldn't detect any heat from it and that it's much more shiny, by a factor of ten, than a typical asteroid or comet. All of these are facts. I am following the facts.

Last year, I wrote a paper about cosmology where there was an unusual result, which showed that perhaps the gas in the universe was much colder than we expected. And so we postulated that maybe dark matter has some property that makes the gas cooler. And nobody cares, nobody is worried about it, no one says it is not science. Everyone says that is mainstream -- to consider dark matter, a substance we have never seen. That's completely fine. It doesn't bother anyone. But when you mention the possibility that there could be equipment out there that is coming from another civilization -- which, to my mind, is much less speculative, because we have already sent things into space -- then that is regarded as unscientific. But we didn't just invent this thing out of thin air. The reason we were driven to put in that sentence was because of the evidence, because of the facts. If someone else has a better explanation, they should write a paper about it rather than just saying what you said.

This discussion has been archived. No new comments can be posted.

Have Aliens Found Us? A Harvard Astronomer on the Mysterious Interstellar Object 'Oumuamua

Comments Filter:
  • So.... (Score:5, Funny)

    by burtosis ( 1124179 ) on Friday January 18, 2019 @09:51AM (#57981472)
    It's never aliens, until it is.
  • by 110010001000 ( 697113 ) on Friday January 18, 2019 @09:52AM (#57981478) Homepage Journal
    How could it be an interstellar probe? The nearest star is over 4 light years away. Are they suggesting some civilization managed to build a probe that can travel at an appreciable percentage of the speed of light? Laws of physics suggests "no". You haven't "seen anything like it before" because we have barely "seen" anything.
    • by s122604 ( 1018036 ) on Friday January 18, 2019 @09:58AM (#57981500)
      Perhaps. Perhaps not... Maybe this civilization takes a long view. The probe could have been sent thousands, or even millions of years ago, at some fraction of C.

      Of course when you think about the fact that less than 200 years ago, if you wanted a picture of something you had to draw it, it's hard to pontificate on what a civilization tens of thousands of years ahead of us could accomplish
      • by codeButcher ( 223668 ) on Friday January 18, 2019 @10:16AM (#57981592)

        Maybe this civilization takes a long view.

        So they have not invented Quarterly Results and Agile? That IS advanced.

        • by judoguy ( 534886 )

          Maybe this civilization takes a long view.

          So they have not invented Quarterly Results and Agile? That IS advanced.

          A truly advanced race if they have outgrown or avoided inventing MBA's.

          I wish to subscribe to their newsletter. (As long as it's not focused on dinner prep)

      • Perhaps. Perhaps not... Maybe this civilization takes a long view. The probe could have been sent thousands, or even millions of years ago, at some fraction of C.

        At least it won't be able to report back until we're long gone.

    • by Jason Levine ( 196982 ) on Friday January 18, 2019 @10:00AM (#57981512) Homepage

      You haven't "seen anything like it before" because we have barely "seen" anything.

      The more we explore the universe, the more we'll see things unlike what we've seen before. It wasn't that long ago that there was a debate as to whether planets even existed outside of our solar system. I've lost count of how many we've found since then, but the first few were definitely "like nothing we've ever seen before." That didn't mean OMG ALIENS! It meant that our understanding of reality had to be tweaked to accommodate this new data, In other words, science.

      Trust me, I'd love if the answer to "what is Oumuamua's origin" was "aliens", but it's more likely something else. Might it cause us to rethink some previously held beliefs? Sure, but it doesn't mean that little green men are going to be zipping by to follow up on their probe's findings.

    • How could it be an interstellar probe? The nearest star is over 4 light years away. Are they suggesting some civilization managed to build a probe that can travel at an appreciable percentage of the speed of light?

      Why would they need to suggest that? Perhaps it was sent on its way tens of thousands of years ago.

      • So some civilization created a probe that can last in interstellar space for tens of thousands of years? Wow. I would like to meet them. Do they make cars?
        • So some civilization created a probe that can last in interstellar space for tens of thousands of years? Wow. I would like to meet them. Do they make cars?

          Yes, but the cars were all built so long ago they still come equipped with 8-track players.

    • How about it came in through a worm hole, natural or artificially made, just outside our solar system?

      I'm not convinced that was an alien probe or anything but I don't think known travel speed restrictions disprove it being an alien probe. It only disproves it having come to our solar system by any means we currently use to move about which is a pretty easy conclusion to come to.

      In other words, if it's an alien probe of course it didn't travel here at sub light speeds.

      • Oh I see. So it could be an alien probe that travelled through a theoretical wormhole which we can't detect. Or it could be a comet. No wonder people hate me here.
      • How about it came in through a worm hole, natural or artificially made, just outside our solar system?

        That would be pure speculative science fiction at the moment. There is no evidence that such a thing as a worm hole that can provide a passageway of matter over distance even exists, or COULD exist. Wormholes like that are purely fiction at the moment and anything that could transmit something like Oumuamua through it aren't even in the speculative sciences.

    • We shouldn't limit our thought process to speed; Perhaps an alien species has found a way to fold space. Who knows? As Thomas Edison once said, and I still believe this to be true, "We don't know a millionth of one percent about anything."
    • by pr0t0 ( 216378 ) on Friday January 18, 2019 @10:49AM (#57981794)

      How did you make the leap of logic that if it was sent, it must have been sent at a point in time requiring a significant speed to reach us at the time we observed it? Is it not plausible that a civilization sent one or perhaps many probes to nearby stars in the distant past in an effort to gain local observational data? The fact that we were here and had the technology to witness it could be complete coincidence.

      I've listened to Dr. Loeb a few times; he's the real deal, publishing much well-regarded scientific work that isn't remotely sensational or controversial. All he's saying here is that so far, alien technology cannot be ruled out and that more mundane models to explain all of our observations have yet to be identified or seem less likely than alien technology.

      Aliens should never be the first thing people run to when facing the unexplained, but it also should not be dismissively ruled out either; unless you are one of those people that deeply want to believe we are all alone in the universe. I would say this falls into the "Extraordinary claims require extraordinary evidence." category, and as the data on Oumuamua is sifted through, there is mounting evidence that it appears to have been designed. However, it also entirely possible that more data will come forward pushing the needle back toward the mundane, and that's fine too.

    • It opens a wormhole the minute it gets out beyond the Oort Cloud and space is becomes flat enough...

      Obviously we don't know; obviously that's the point; more than a little is going to slip through our incomplete and inaccurate models of physics, leaving lots of possibilities.

    • by sinij ( 911942 )

      How could it be an interstellar probe? The nearest star is over 4 light years away.

      Our civilization was potentially detectable for at least last 10,000 years and feasibly detectable during technological civilization of 3000 years. For example, widespread cultivation of plants (i.e. agrarian civilization) potentially can be detected by analyzing light spectrum reflected by the planet. Our technology can't do that right now, we don't have good enough optics or historical data to ran models, but considering that we developed ability to detect plants in the past couple decades, it only makes

      • So this could be an alien probe that was launched and lasted in space 85 years ago at 53,963,000 km/h from Proxima Centauri. Or it could be a comet.
    • by Ecuador ( 740021 ) on Friday January 18, 2019 @11:08AM (#57981922) Homepage

      How could it be an interstellar probe? The nearest star is over 4 light years away. Are they suggesting some civilization managed to build a probe that can travel at an appreciable percentage of the speed of light? Laws of physics suggests "no". You haven't "seen anything like it before" because we have barely "seen" anything.

      Wait, why do you think it is hard to build a probe that can travel at an appreciable percentage of the speed of light? Even a constant acceleration of just 1g would get you to relativistic speeds during interstellar travel. In fact, if we put a significant part of our money/resources on it, the tech to visit a star 4ly away at a reasonable time-frame is within reach (e.g. nuclear pulse propulsion). But to actually have a serious chance of finding the right star system, AT THE RIGHT TIME to come upon an alien civilization would probably require us to visit at least a few hundred thousand stars (still nothing compared to just our own galaxy), so that would take pretty much "forever" (in human time scale terms) even at relativistic speeds (well, OK, Von Neumann probes would be faster, but still...).
      And this object wasn't even fast (0.008%c or something like that). There don't have to be aliens to explain interstellar objects just because we don't get to see them all the time. Just a rock passing by...

      Of course it could always be a moon with an alien starbase propelled by a nuclear storage accident...

    • by gtall ( 79522 )

      I think we should start broadcasting messages asking in pictographs whether anyone out there is missing a probe.

    • by Thelasko ( 1196535 ) on Friday January 18, 2019 @11:31AM (#57982108) Journal

      Are they suggesting some civilization managed to build a probe that can travel at an appreciable percentage of the speed of light?

      That's not what he's saying at all. He's saying the objects motion is statistically unlike anything else in our part of the Milky Way. [wikipedia.org] It's essentially stationary with respect to the rest of the galaxy. A large amount of energy would be needed to achieve that relative velocity. He also notes that it has several characteristics, including acceleration, that are similar to current solar sail technology. It's a statistical anomaly.

      I may have missed something, but he also doesn't mention it being uses specifically to study Earth. His hypothesis is that its use is to mark a specific reference point in the galaxy. Our solar system passed by it, not the other way around.

  • Hacktivist group Anonymous posted this video on Youtube ( https://www.youtube.com/watch?... [youtube.com] ) just 19 hours ago. Its about the mysterious, only partly-excavated Göbeklitepe ruins in Turkey. Anonymous claims that this site, like the Giza Pyramids, is perfectly aligned with certain star constellations, and that strange repeating radio signals from those stars - picked up by radio telescopes - appear to be aimed at the still not fully excavated structures at Göbeklitepe. Mysterious stuff indeed.
    • by dargaud ( 518470 )
      Göbekli tepe [wikipedia.org] is THE most interesting archeological site discovered in the last century. There are so many strange and fascinating things about it that it boggles the mind, but to add alien conspiracy theories to it is simply bullshit, as usual.
  • He seems a bit salty (Score:4, Interesting)

    by MaSeKind ( 1205810 ) on Friday January 18, 2019 @10:00AM (#57981510)
    that people don't want to just agree this was aliens. I'm all for it being aliens. In fact I hope it was and they either invade (soon please) or just come and visit. We need some crazy shit to shake things up here on Earth. But with our very limited knowledge of the universe this might just be a common type of asteroid or something we've not encountered before.
    • by Gaxx ( 76064 ) on Friday January 18, 2019 @10:35AM (#57981704)

      He seems a bit salty that people don't want to just agree this was aliens.

      I think it's a bit more complicated than that. I think he is upset that his hypothesis isn't being given any credence, even at the level of hypothesis. Which, I think, might be fair.

      It is also entirely reasonable that the scientific community is extremely reluctant to be seen giving the hypothesis any real credence. Unfortunately, UFO and panspermia crackpots have poisoned that well.

  • Have Aliens Found Us? Maybe, but if they have Oumuamua has got nothing to do with them in all possibility.

    Any species capable of sending Oumuamua towards us would almost certainly have the means to send a more efficient craft towards us. Unless they were trying to hide from our detection; and if they were trying to hide from our detection they would have had a better means of hiding from us.

    • by es330td ( 964170 )

      Any species capable of sending Oumuamua towards us would almost certainly have the means to send a more efficient craft towards us.

      They may *today*. They may not have when this was launched. My 100 year old grandmother remembered when the first car came to her town. In her lifetime people went from literal horsepower to walking on the moon. Pretty sure we are going to one day think "I remember when..." in reference to some technology about which we currently have no clue.

      • They may *today*. They may not have when this was launched. My 100 year old grandmother remembered when the first car came to her town. In her lifetime people went from literal horsepower to walking on the moon. Pretty sure we are going to one day think "I remember when..." in reference to some technology about which we currently have no clue.

        My point is, if you can launch something the size of Oumuamua, you're likely to have the technology to send something smaller. Something smaller would be less likely to have collisions with other objects, and use much less energy to launch at such speeds.

        • by jythie ( 914043 )
          Within the paper's suggestion though. Oumuamua would be mostly light sail, which doesn't really scale down since the surface area is the important part.
  • It's not like this wasn't foretold. All Loeb had to do was read the three books by Arthur C. Clarke (two co-written with Gentry Lee).

    The problem is, we didn't have any spacecraft able to intercept the object and have people land on it when they found the docking port. We missed our first opportunity with alien technology.

    Now we'll have to wait until the next one comes round and answers some of our questions. We need to get ready now so when the next opportunity presents itself, it won't be wasted.

  • Ancient Sumerians believed their gods were aliens. https://youtu.be/L3ogy-pqvKQ [youtu.be]
    • Ancient Sumerians believed their gods were aliens. https://youtu.be/L3ogy-pqvKQ [youtu.be]

      Modern day Scientologists do too (no surprise there since the religion was created as a get-rich-quick scheme by a Science Fiction author).

      One could possibly interpret God as being an "alien" in the Mormon branch of Christianity too- although I don't think Mormons like that analogy.

  • The New Yorker: Your explanation of why 'Oumuamua might be an interstellar probe may be hard for laypeople to understand.

    That's because it's bullshit.

    We see the solar system and we can calculate at what rate it ejected rocks during its history. And if we assume all planetary systems around other stars are doing the same thing, we can figure out what the population of interstellar objects should be. That calculation results in a lot of possibilities, but the range is much less than needed to explain the discovery of 'Oumuamua.

    It's a single event. The error bars around any single event are enormous if you are going to use it to infer a population. Additionally these sorts of objects are rather hard to see so it's hardly shocking that we haven't seen a LOT of them. Furthermore there is a lot of stuff in our solar system we know we cannot yet see and we're discovering new stuff all the time.

    When you look at all the stars in the vicinity of the sun, they move relative to the sun, the sun moves relative to them, but only one in five hundred stars in that frame is moving as slow as 'Oumuamua. You would expect that most rocks would move roughly at the speed of the star they came from.

    Self defeating argument. Even if we take his 1/500 number at face value (we shouldn't) there are literally bil

  • It didn't hit Buenos Aires. /s

    • by Nidi62 ( 1525137 )

      It didn't hit Buenos Aires. /s

      The Bugs are still bracketing Earth. If there's another one that passes to the other side, then we are in trouble and they know where we are.

  • by johnsie ( 1158363 ) on Friday January 18, 2019 @10:33AM (#57981680)
    They investigated planet earth and couldn't find any intelligent life-forms, so continued on their mission.
  • The big difference between his theories on dark matter cooling space gas and this rock being an interstellar probe is that one makes potential hypotheses that are testable and the other does not.

    The former is fine theoretical science -even if it's largely speculative. The latter is just speculation, even if it's backed up by some data.

    This discussion is very similar to people that look for the star of Bethlehem using computer software. They have certain facts from the bible, and then scour the ancient sky u

    • by shess ( 31691 )

      This discussion is very similar to people that look for the star of Bethlehem using computer software. They have certain facts from the bible, and then scour the ancient sky using powerful astronomy software looking for events and things that they think match up with the facts. That's not science, even though it's "backed up by fact", so to speak.

      So the star of Bethlehem was basically Oumuamua's launching lasers? Illuminati confirmed!

  • by Tablizer ( 95088 ) on Friday January 18, 2019 @11:42AM (#57982176) Journal

    Multiple things that have at first looked "suspiciously artificial" turned out to be natural. The consistent pulsing of pulsars is one of the most common examples. Occam's Razor says Oumuamua is probably natural in ways we didn't anticipate.

    However, it was a curious object that did deserve more inspection even if natural, and hopefully if another one buzzes by, we'll be more ready.

  • by argStyopa ( 232550 ) on Friday January 18, 2019 @12:00PM (#57982286) Journal

    From TFA https://blogs.scientificameric... [scientificamerican.com]

    Of his 6 "odd facts" about the object, at least 4 aren't persuasive at all:
    1) They did a paper projecting the estimated population of interstellar ejecta. They assert that 'stumbling' onto this implies a much higher population - how do they conclude that from a sample size of one? Even if the odds of running into such an object are astonishingly low, because they're non-zero the presence of ONE sample means nothing. His conclusions all flow from the assumption that the object was statistically common; I'm not sure that is much of a springboard for all of his other conclusions.

    2) it's moving very slowly - essentially we raced past it. He observes that only one in the neighborhood of 500 stars is moving that slowly. (And then opines that this would be 'optimal to camouflage the origin of a probe' and 'it's like a buoy we raced past, could it be part of a communication net work'? Anthropomorphic tinfoil hat, anyone? Of course, again: single sample. It could be BILLIONS of years old, from well outside the local 500 star group, to say nothing of the literally-infinite number of possibilities of caroming around bouncing off crap or (my guess) slowing due to passing through any number of dust/debris clouds.

    3) ejecta from planetary systems would likely have high energy vs local rest frame, this was barely moving. See points 1 and 2 above.

    4) the inferred geometry from the 10:1 brightness curve variation observed only sustains if you assume its homogeneous or at least its reflectivity is. While not a bad GUESS to suggest it's a tumbling needle-shape, there are also a LOT of other explanations for such variation (to use only my example above, it could be an icy object (high albedo) that's passed through heavy carbon dust clouds (very low albedo to the surface that's facing such clouds). It wouldn't take an oddly proportioned object nor much spin to result in a highly-fluctuating brightness.

    5) lock of heating even though it passed close to the sun (inside orbit of mercury)
    and
    6) slight deviation from the predictable Keplerian gravity-calculated path, comparable to the shift from outgassing (but there's no evidence/suggestion that this happened, and in fact some evidence it DIDN'T happen)

    5 & 6 are IMO meaningful. I fully agree with him that we should both a) work on very high speed probes that COULD in fact catch it before it leaves the solar system (by God yes!) and b) look for more high-inclination objects around our large gas giants to see if we can find anything 'caught' by their wells historically (he doesn't mention that chronology is against us here; if they were caught, they would be high-off the ecliptic, wouldn't be very stable, and would likely either impact one of the Jovian moons or ultimately end up in Jupiter itself relatively quickly).

    I strongly doubt (though I certainly wish it were true) that this is an artificial object of extra-solar origin. There are too many other more-reasonable explanations. The breathlessness and hand-waving of the SA article are unworthy of an actual science publication.

    Then again, the fact that this was published in SA doesn't shock me, it's 'standards' over the last 20 years have dropped to about that of Reddit.

All the simple programs have been written.

Working...