# Oumuamua: Aliens! **URL:** \ **Category:** Miscellaneous and Personal Stuff I Must Share\ **Created:** [November 6, 2018, 8:41am UTC](https://boards.straightdope.com/t/oumuamua-aliens/824062 "2018-11-06T08:41:40Z")\ **Posts on this page:** 20\ **Page:** 4
**Author:** ![Darren\_Garrison](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darren_garrison/32/92_2.png) [@Darren\_Garrison](https://boards.straightdope.com/u/Darren_Garrison)\ **Post date:** [November 10, 2018, 2:13pm UTC](https://boards.straightdope.com/t/oumuamua-aliens/824062/61 "2018-11-10T14:13:47Z")
> [@eschereal](#): > > The premise is that there is some sort of sail that would use sunlight/solar wind for impetus. Oumuamua itself is a pretty small thing, and any sail-like attachment would probably not be very east to image. The calculation was _not_ based on the idea that Oumuamua is attached to a solar sail [but that \*Oumuamua itself \*was a solar sail](http://astronomy.com/news/2018/11/interstellar-visitor-oumuamua-is-probably-not-an-alien-solar-sail). ---
**Author:** ![Atomic\_Alex](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/atomic_alex/32/175_2.png) [@Atomic\_Alex](https://boards.straightdope.com/u/Atomic_Alex)\ **Post date:** [November 11, 2018, 4:57pm UTC](https://boards.straightdope.com/t/oumuamua-aliens/824062/62 "2018-11-11T16:57:03Z")
> [@Sam\_Stone](#): > > Please remember that all this speculation is based on an extremely thin dataset. We have a light curve that can be interpreted as a long, cigar shaped object tumbling around two axes, but that’s just an interpretation. I suspect you could come up with a similar light curve of a rotating spherical object with radical differences in Albedo on its surface, too. > > The bottom line is that this is all the data we will ever have on this object and it’s not enough to even definitively determine its shape. Optically we have never seen this thing with enough resolution to see it as anything other than a pinpoint. I was doing a little more reading on this and that’s one thing that struck me as well, as you say given the extremely limited about of information we have on the object how are we so certain what shape it was? > [@EastUmpqua](#): > > If the stupid thing hadn’t accelerated away from the Sun Apparently it didn’t accelerate away, it just didn’t decelerate as much as expected, which is something else entirely. On the other hand it did come in at pretty much the optimal angle for a gravitational assist from the sun and from a good position to get a look at the solar system beforehand and came through at a decent range to check out an interesting blue planet. I don’t think it was an alien probe, but I don’t agree that its such an outlandish thing to consider and its fun to speculate about. ---
**Author:** ![Darren\_Garrison](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darren_garrison/32/92_2.png) [@Darren\_Garrison](https://boards.straightdope.com/u/Darren_Garrison)\ **Post date:** [November 11, 2018, 7:49pm UTC](https://boards.straightdope.com/t/oumuamua-aliens/824062/63 "2018-11-11T19:49:00Z")
I’m going to speculate that it is a tree filled with Keebler elves and they toss chocolate chips out the back for reaction mass. Gosh, that _is_ fun! ---
**Author:** ![k9bfriender](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/k9bfriender/32/3283_2.png) [@k9bfriender](https://boards.straightdope.com/u/k9bfriender)\ **Post date:** [November 11, 2018, 9:15pm UTC](https://boards.straightdope.com/t/oumuamua-aliens/824062/64 "2018-11-11T21:15:45Z")
> [@Chronos](#): > > Oh, and there’s also another argument against it being a solar sail: Solar sails are flat (or at least, there’s no reason for them not to be), and very thin. Unless it were deliberately taking measures to mislead us, the plane of the sail would at some point have crossed us, at which point its light curve would have dipped to zero. We didn’t see that. > > And if it is taking deliberate measures to deceive us, we can’t conclude anything at all, because any alien capable of sending probes across interstellar space would be capable of complete deception (including complete stealth, if that’s what they wanted). I have more than a bit of skepticism about the alien intelligence nature of Oumuamua myself, but as far as that goes, if there were a probe sent to check out our solar system, then what we are seeing is not necessarily the craft, but the discarded solar sail that brought it here. That would explain why it is no longer flat and thin, but instead starting to wrinkle and curl up. ---
**Author:** ![Atomic\_Alex](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/atomic_alex/32/175_2.png) [@Atomic\_Alex](https://boards.straightdope.com/u/Atomic_Alex)\ **Post date:** [November 11, 2018, 9:21pm UTC](https://boards.straightdope.com/t/oumuamua-aliens/824062/65 "2018-11-11T21:21:23Z")
> [@k9bfriender](#): > > I have more than a bit of skepticism about the alien intelligence nature of Oumuamua myself, but as far as that goes, if there were a probe sent to check out our solar system, then what we are seeing is not necessarily the craft, but the discarded solar sail that brought it here. > > That would explain why it is no longer flat and thin, but instead starting to wrinkle and curl up. Its certainly a more plausible ‘First Contact’ scenario than a silver disc landing on the White House lawn. A pity any follow-up will probably take several millennia. ---
**Author:** ![EastUmpqua](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/eastumpqua/32/6025_2.png) [@EastUmpqua](https://boards.straightdope.com/u/EastUmpqua)\ **Post date:** [November 16, 2018, 2:01am UTC](https://boards.straightdope.com/t/oumuamua-aliens/824062/66 "2018-11-16T02:01:42Z")
Interstellar object ‘Oumuamua’ is probably a small, surprisingly shiny comet. This brilliant conclusion is based on analysis of data from NASA’s Spitzer Space Telescope from November 2017. Spitzer couldn’t find Oumuamua. That’s because it changed course and accelerated. ---
**Author:** ![Darren\_Garrison](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darren_garrison/32/92_2.png) [@Darren\_Garrison](https://boards.straightdope.com/u/Darren_Garrison)\ **Post date:** [November 16, 2018, 3:00am UTC](https://boards.straightdope.com/t/oumuamua-aliens/824062/67 "2018-11-16T03:00:09Z")
In a completely unrelated question, how many roll-eyes icons can you put in a reply window before the SMDB software cuts you off? ---
**Author:** ![EastUmpqua](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/eastumpqua/32/6025_2.png) [@EastUmpqua](https://boards.straightdope.com/u/EastUmpqua)\ **Post date:** [November 16, 2018, 3:36am UTC](https://boards.straightdope.com/t/oumuamua-aliens/824062/68 "2018-11-16T03:36:58Z")
> [@Darren\_Garrison](#): > > In a completely unrelated question, how many roll-eyes icons can you put in a reply window before the SMDB software cuts you off? Darren, with all due respect, you seem to post like a troll. If your religious beliefs, or whatever, forbid you from investigating the possibility another civilization exists out there in this vast universe, why follow this thread? ---
**Author:** ![Darren\_Garrison](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darren_garrison/32/92_2.png) [@Darren\_Garrison](https://boards.straightdope.com/u/Darren_Garrison)\ **Post date:** [November 16, 2018, 4:10am UTC](https://boards.straightdope.com/t/oumuamua-aliens/824062/69 "2018-11-16T04:10:28Z")
> [@EastUmpqua](#): > > If your religious beliefs, or whatever, forbid you from investigating the possibility another civilization exists out there in this vast universe, why follow this thread? Look at line below the large “Straight Dope” in the header image. Debunking bunk is one of the primary purposes for this site. ---
**Author:** ![EastUmpqua](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/eastumpqua/32/6025_2.png) [@EastUmpqua](https://boards.straightdope.com/u/EastUmpqua)\ **Post date:** [November 16, 2018, 4:34am UTC](https://boards.straightdope.com/t/oumuamua-aliens/824062/70 "2018-11-16T04:34:02Z")
> [@Darren\_Garrison](#): > > Look at line below the large “Straight Dope” in the header image. Debunking bunk is one of the primary purposes for this site. What makes you think you’ve debunked anything? Eye-roll icons don’t count. It’s interesting that you seem to have such a good understanding of the capabilities of an alien technology. The Earth’s not flat, and we might not be alone in the Universe either. ---
**Author:** ![eschereal](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/eschereal/32/18939_2.png) [@eschereal](https://boards.straightdope.com/u/eschereal)\ **Post date:** [November 16, 2018, 4:56am UTC](https://boards.straightdope.com/t/oumuamua-aliens/824062/71 "2018-11-16T04:56:50Z")
[Here is a source](https://arstechnica.com/science/2018/11/oumuamua-was-fairly-small-further-suggesting-a-natural-origin/) that is well-regarded and employs people who ken sciency stuff. Spitzer could not see 'Oumuamua because it is ridiculously small and low-albedo. Not being able to see it (like trying to spot a dark red ping pong ball in the garage with the lights turned off) is useful information that tells them how big it could not be. Now it has rolled out the driveway on a moonless night, down the street and probably into a sewer grate where we will never be able to see it again. ---
**Author:** ![Darren\_Garrison](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darren_garrison/32/92_2.png) [@Darren\_Garrison](https://boards.straightdope.com/u/Darren_Garrison)\ **Post date:** [November 16, 2018, 5:20am UTC](https://boards.straightdope.com/t/oumuamua-aliens/824062/72 "2018-11-16T05:20:38Z")
Ridiculously small and _high_-albedo, you mean. The higher, the brighter. ---
**Author:** ![eschereal](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/eschereal/32/18939_2.png) [@eschereal](https://boards.straightdope.com/u/eschereal)\ **Post date:** [November 16, 2018, 6:26am UTC](https://boards.straightdope.com/t/oumuamua-aliens/824062/73 "2018-11-16T06:26:19Z")
No, it is a dim thing. Looks like it has a lower albedo than almost everything we know of in our system. Brighter than a piece of coal, but that would not be saying much. Yet, it just occurred to me that Spitzer is an IR telescope – which is why it is in space. It looks for black body radiation: heat. So albedo is not very relevant. If it still had some helium in its tanks, it might have been able to crank up the fancy-ass sensors and get a better look, but that stuff ran out a long time back. ---
**Author:** ![Darren\_Garrison](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darren_garrison/32/92_2.png) [@Darren\_Garrison](https://boards.straightdope.com/u/Darren_Garrison)\ **Post date:** [November 16, 2018, 7:20am UTC](https://boards.straightdope.com/t/oumuamua-aliens/824062/74 "2018-11-16T07:20:07Z")
[No](https://www.nasa.gov/feature/jpl/nasa-learns-more-about-interstellar-visitor-oumuamua): > [@](#): > > The new study also suggests that 'Oumuamua may be up to 10 times more reflective than the comets that reside in our solar system — a surprising result, according to the paper’s authors. Because infrared light is largely heat radiation produced by “warm” objects, it can be used to determine the temperature of a comet or asteroid; in turn, this can be used to determine the reflectivity of the object’s surface — what scientists call albedo. Just as a dark T-shirt in sunlight heats up more quickly than a light one, an object with low reflectivity retains more heat than an object with high reflectivity. So a lower temperature means a higher albedo. ---
**Author:** ![Lucas\_Jackson](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lucas_jackson/32/303_2.png) [@Lucas\_Jackson](https://boards.straightdope.com/u/Lucas_Jackson)\ **Post date:** [February 8, 2019, 7:01am UTC](https://boards.straightdope.com/t/oumuamua-aliens/824062/75 "2019-02-08T07:01:11Z")
> **[Astronomer offers entirely new theory to explain 'alien probe' asteroid](https://bgr.com/science/oumuamua-explanation-dust-cloud-debris-astronomy/)** > > If there’s one story that left astronomers truly scratching their heads in 2018, it had to be the mysterious interstellar visitor known as Oumuamua. The … They say now that it appears to be a dust cloud. “Rather than a solid rock or chunk of debris, Sekanina explains that Oumuamua might be “a monstrous fluffy dust aggregate released in recent explosive event.” The cloud of dust, swirling and spinning as it travels through space, would account for some of the body’s more peculiar characteristics as observed by astronomers.” ---
**Author:** ![dtilque](https://avatars.discourse-cdn.com/v4/letter/d/d6d6ee/32.png) [@dtilque](https://boards.straightdope.com/u/dtilque)\ **Post date:** [February 8, 2019, 7:41am UTC](https://boards.straightdope.com/t/oumuamua-aliens/824062/76 "2019-02-08T07:41:07Z")
A small dust cloud should have problems staying together when going through the solar system. Tidal effects, light pressure, and the solar wind should fragment it. Unless maybe they think it was formed locally, but then how did it get into a hyperbolic orbit? ---
**Author:** ![Musicat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/musicat/32/20189_2.png) [@Musicat](https://boards.straightdope.com/u/Musicat)\ **Post date:** [February 8, 2019, 11:51am UTC](https://boards.straightdope.com/t/oumuamua-aliens/824062/77 "2019-02-08T11:51:02Z")
> [@dtilque](#): > > A small dust cloud should have problems staying together when going through the solar system… Why should we assume that we are seeing 100% of the original object? Comets lose a little bit of mass with every orbital pass, but we can see them, at least for a while. ---
**Author:** ![Quimby](https://avatars.discourse-cdn.com/v4/letter/q/22d042/32.png) [@Quimby](https://boards.straightdope.com/u/Quimby)\ **Post date:** [February 8, 2019, 9:54pm UTC](https://boards.straightdope.com/t/oumuamua-aliens/824062/78 "2019-02-08T21:54:09Z")
Or it was Venus…no Swamp gas…yeah Swamp Gas. Definitely not Aliens that have already come down to Earth and are among us. Perhaps even someone you know. Definitely not that. ---
**Author:** ![Lumpy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lumpy/32/446_2.png) [@Lumpy](https://boards.straightdope.com/u/Lumpy)\ **Post date:** [February 11, 2019, 2:47am UTC](https://boards.straightdope.com/t/oumuamua-aliens/824062/79 "2019-02-11T02:47:13Z")
Some questions: How fast was Oumuamua going through interstellar space before falling into our solar system? If you backtrack its course, does it (within error bars) come from an identifiable source? If so, how long would it have taken to get here? At its present speed and direction, is it **going** anywhere obvious? There was talk of it undergoing non-gravitational acceleration. How much are we talking about: a miniscule amount that’s no more than a microscopic nudge, or a more significant value? Does the observed acceleration vary in a manner consistent with outgassing from sources matching its inferred rotation period? Or does it match a very light object undergoing acceleration due to light pressure? Or is the acceleration along a constant vector? If it’s outgassing, why the f\*\*\* haven’t we _observed_ any gas or dust? ---
**Author:** ![Darren\_Garrison](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darren_garrison/32/92_2.png) [@Darren\_Garrison](https://boards.straightdope.com/u/Darren_Garrison)\ **Post date:** [February 11, 2019, 3:27am UTC](https://boards.straightdope.com/t/oumuamua-aliens/824062/80 "2019-02-11T03:27:19Z")
> [@Lumpy](#): > > Some questions: > > How fast was Oumuamua going through interstellar space before falling into our solar system? 26 km/s relative to the sun. > [@](#): > > If you backtrack its course, does it (within error bars) come from an identifiable source? If so, how long would it have taken to get here? [See this](https://en.wikipedia.org/wiki/%CA%BBOumuamua#Indications_of_origin). > [@](#): > > At its present speed and direction, is it **going** anywhere obvious? [In the direction of Pegasus. It will take 20,000 years to leave our solar system](https://www.quora.com/Where-is-Oumuamua-going). > [@](#): > > There was talk of it undergoing non-gravitational acceleration. How much are we talking about: a miniscule amount that’s no more than a microscopic nudge, or a more significant value? [A difference of 0.01%](https://www.gotscience.org/2018/07/interstellar-asteroid-accelerating/). [Previous page](https://boards.straightdope.com/t/oumuamua-aliens/824062.md?page=3) [Next page](https://boards.straightdope.com/t/oumuamua-aliens/824062.md?page=5)