# 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:** 2
**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 7, 2018, 7:31pm UTC](https://boards.straightdope.com/t/oumuamua-aliens/824062/21 "2018-11-07T19:31:49Z")
> [@Projammer](#): > > The first article I read suggested the acceleration was more than could reasonably be explained by outgassing. It would seriously rock if some of our radio telescopes picked up a burst signal from Oumuamua even if it used a compression algorithm we had no hope of decrypting. There’s an interesting comment by John on: https: [//www.centauri-dreams.org/2018/10/29/on-oumuamua-thin-films-and-lightsails/](https://www.centauri-dreams.org/2018/10/29/on-oumuamua-thin-films-and-lightsails/) (link broken but it should be safe enough anyway) “Every one here seems t speculate that if this was a probe it is currently sailing away. I believe that if it is indeed a probe it detached from the solar sail near perihelion causing the solar sail to tumble. The probe itself could be of the size of a smartphone and has probably further decelerated after detaching from the sail. It is now perhaps heading towards earth. But given the size of the probe it is unlikely we will be capable of detecting it.” If it was travelling unpowered how long would it take such an object to reach Earth? What I’m saying is do I need to stock up and/or run around in a hand-flailing panic now or later? ---
**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 7, 2018, 8:05pm UTC](https://boards.straightdope.com/t/oumuamua-aliens/824062/22 "2018-11-07T20:05:35Z")
> [@Atomic\_Alex](#): > > There’s an interesting comment by John on: https: [//www.centauri-dreams.org/2018/10/29/on-oumuamua-thin-films-and-lightsails/](https://www.centauri-dreams.org/2018/10/29/on-oumuamua-thin-films-and-lightsails/) (link broken but it should be safe enough anyway) > > “Every one here seems t speculate that if this was a probe it is currently sailing away. I believe that if it is indeed a probe it detached from the solar sail near perihelion causing the solar sail to tumble. The probe itself could be of the size of a smartphone and has probably further decelerated after detaching from the sail. It is now perhaps heading towards earth. But given the size of the probe it is unlikely we will be capable of detecting it.” > > If it was travelling unpowered how long would it take such an object to reach Earth? What I’m saying is do I need to stock up and/or run around in a hand-flailing panic now or later? It wouldn’t be headed for Earth because it would be traveling in the same direction and speed as the rest of the object at the time of detachment and would not have the ability to change it’s direction and speed to reach Earth. “John” is an idiot. ---
**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 7, 2018, 8:13pm UTC](https://boards.straightdope.com/t/oumuamua-aliens/824062/23 "2018-11-07T20:13:47Z")
> [@Darren\_Garrison](#): > > It wouldn’t be headed for Earth because it would be traveling in the same direction and speed as the rest of the object at the time of detachment and would not have the ability to change it’s direction and speed to reach Earth. “John” is an idiot. That makes sense, thank you. Still, it would be a shame to waste a good panic. ---
**Author:** ![Miller](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/miller/32/481_2.png) [@Miller](https://boards.straightdope.com/u/Miller)\ **Post date:** [November 8, 2018, 12:03am UTC](https://boards.straightdope.com/t/oumuamua-aliens/824062/24 "2018-11-08T00:03:52Z")
> [@Darren\_Garrison](#): > > It wouldn’t be headed for Earth because it would be traveling in the same direction and speed as the rest of the object at the time of detachment and **would not have the ability to change it’s direction and speed to reach Earth**. “John” is an idiot. Given the assumption that Oumuamua was some sort of alien space craft, and not just a random space rock, I’m not sure what you’re basing the bolded part on. ---
**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 8, 2018, 3:00am UTC](https://boards.straightdope.com/t/oumuamua-aliens/824062/25 "2018-11-08T03:00:23Z")
> [@Miller](#): > > Given the assumption that Oumuamua was some sort of alien space craft, and not just a random space rock, I’m not sure what you’re basing the bolded part on. I’m basing the bolded part on that if the alien civilization had the miracle propulsion technology to allow a “cell phone sized object” to move from a hyperbolic to the sun course into one that intersected with the Earth (in any form other than a particularly bright meteor) they would have no need for something so primitive as a solar sail. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [November 8, 2018, 3:41am UTC](https://boards.straightdope.com/t/oumuamua-aliens/824062/26 "2018-11-08T03:41:10Z")
It’s fun to imagine, but I have a hard time buying it. The thing with solar sails is, they’re big. Really big, and opaque. If this thing were a solar sail, we’d have seen it. ---
**Author:** ![popomomo\_cocoyoyo](https://avatars.discourse-cdn.com/v4/letter/p/3da27b/32.png) [@popomomo\_cocoyoyo](https://boards.straightdope.com/u/popomomo_cocoyoyo)\ **Post date:** [November 8, 2018, 3:53am UTC](https://boards.straightdope.com/t/oumuamua-aliens/824062/27 "2018-11-08T03:53:09Z")
This is weird cause I just read the exact opposite in the local free rag: [The strange ‘Oumuamua comet was not sent by aliens to save us](https://www.thestar.com/news/world/2018/11/06/the-strange-oumuamua-comet-was-not-sent-by-aliens-to-save-us.html). > [@](#): > > As astrophysicist Katie Mack pointed out on Twitter, coming up with far-out explanations for slightly strange phenomena is one of astronomers’ favourite parlour games. (Remember the alien megastructure that turned out to be a star swathed in dust?) > > That doesn’t mean you need to stock up on canned goods and tin foil hats every time a weird theory gets published. > > “Until every other possibility has been exhausted dozen times over, even the authors probably don’t believe it,” Mack said. > > Other astronomers were not so forgiving of their colleagues’ speculation. > > Paul M. Sutter tweeted “My publicist asked me for a quote on the ‘Oumuamua story making the rounds. Here it is: > > “’No, ‘Oumuamua is not an alien spaceship, and the authors of the paper insult honest scientific inquiry to even suggest it.’ ---
**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 8, 2018, 4:01am UTC](https://boards.straightdope.com/t/oumuamua-aliens/824062/28 "2018-11-08T04:01:50Z")
It’s interesting that some folks seem to know whether or not alien spacecrafts are opaque or emit EM. If it’s a probe, do you think its builders have FTL technology? ---
**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 8, 2018, 4:37am UTC](https://boards.straightdope.com/t/oumuamua-aliens/824062/29 "2018-11-08T04:37:40Z")
> [@](#): > > It’s interesting that some folks seem to know whether or not alien spacecrafts are opaque or emit EM. If it’s a probe, do you think its builders have FTL technology? A solar sail would have to be opaque because that is the whole purpose of a solar sail–to have light not pass through it. If it wasn’t opaque it wouldn’t be a solar sail. We know that the probe didn’t emit EM because we looked for that: > [@](#): > > The SETI Institute’s radio telescope, the Allen Telescope Array, examined ʻOumuamua, but detected no unusual radio emissions.[37] More detailed observations, using the Breakthrough Listen hardware and the Green Bank Telescope, were performed;[33][37][38] the data were searched for narrowband signals and none were found. Given the close proximity to this interstellar object, limits were placed to putative transmitters with the extremely low power of 0.08 watts. Any civilization with FTL wouldn’t be using probes that take millions of years to reach nearby stars. ---
**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 8, 2018, 4:45am UTC](https://boards.straightdope.com/t/oumuamua-aliens/824062/30 "2018-11-08T04:45:24Z")
BTW, the above quote (which I can’t edit to add a link) was [from Wikipedia](https://en.wikipedia.org/wiki/%CA%BBOumuamua). ---
**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 8, 2018, 4:54am UTC](https://boards.straightdope.com/t/oumuamua-aliens/824062/31 "2018-11-08T04:54:53Z")
There’s no reason an advanced technology couldn’t harness charged particles from a star with a device that’s not opaque. Why should it emit EM? How do you know how long it took Oumuamua to get here? ---
**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 8, 2018, 5:11am UTC](https://boards.straightdope.com/t/oumuamua-aliens/824062/32 "2018-11-08T05:11:06Z")
But why do we assume they are communicating using some form of EM? Because that is all we know? The ship contained a massive drive system that manipulates the vacuum energy field, which is why the acceleration profile resembled a solar sail: it is comparatively low output in steep gravitational gradients, like near the sun. And their communication system modulates the polarity of the same vacuum energy – the pervasive “dark energy” that we cannot seem to detect. That is why it looks like just an old rock or something. ---
**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 8, 2018, 5:15am UTC](https://boards.straightdope.com/t/oumuamua-aliens/824062/33 "2018-11-08T05:15:30Z")
[A solar sail](https://en.wikipedia.org/wiki/Solar_sail) is based on propulsion from photons, not charged particles. Charged particles would supply around a thousand times less propulsion than photon pressure. It wouldn’t be a probe if it wasn’t emitting EM (and please skip the neutrino beam nonsense.) We guess how long it took to get here based on it’s speed on approaching and estimating which stars it was near in the past. Close encounters with other stars are millions of years back. But even those don’t mean that the object must have come from one of those stars and the near approach could be coincidental, so the real figure could be anywhere from a few million years to many times that figure. ---
**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 8, 2018, 5:18am UTC](https://boards.straightdope.com/t/oumuamua-aliens/824062/34 "2018-11-08T05:18:11Z")
> [@eschereal](#): > > But why do we assume they are communicating using some form of EM? Because that is all we know? The ship contained a massive drive system that manipulates the vacuum energy field, which is why the acceleration profile resembled a solar sail: it is comparatively low output in steep gravitational gradients, like near the sun. And their communication system modulates the polarity of the same vacuum energy – the pervasive “dark energy” that we cannot seem to detect. That is why it looks like just an old rock or something. You know the old phrase “when you see hoofprints, think horses, not zebra?” Well, this is seeing hoofprints and thinking invisible pink unicorns. ---
**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 8, 2018, 5:36am UTC](https://boards.straightdope.com/t/oumuamua-aliens/824062/35 "2018-11-08T05:36:24Z")
Darren open your mind… A magnetic sail or magsail is a proposed method of spacecraft propulsion which would use a static magnetic field to deflect charged particles radiated by the Sun as a plasma wind, and thus impart momentum to accelerate the spacecraft.[1][2] A magnetic sail could also thrust directly against planetary and solar magnetospheres. ---
**Author:** ![DrDeth](https://avatars.discourse-cdn.com/v4/letter/d/b487fb/32.png) [@DrDeth](https://boards.straightdope.com/u/DrDeth)\ **Post date:** [November 8, 2018, 5:43am UTC](https://boards.straightdope.com/t/oumuamua-aliens/824062/36 "2018-11-08T05:43:01Z")
> [@Darren\_Garrison](#): > > You know the old phrase “when you see hoofprints, think horses, not zebra?” Well, this is seeing hoofprints and thinking invisible > pink unicorns. Why? I mean sure anal probes and little grey men and all such is tinfoil hat stuff. But the universe is BIG. There’s no reason there couldn’t be aliens out there, who sent a probe a little bit like Voyager. This may be at the fringe but it’s not tinfoil hat crap. ---
**Author:** ![Regallag\_The\_Axe](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/regallag_the_axe/32/445_2.png) [@Regallag\_The\_Axe](https://boards.straightdope.com/u/Regallag_The_Axe)\ **Post date:** [November 8, 2018, 5:57am UTC](https://boards.straightdope.com/t/oumuamua-aliens/824062/37 "2018-11-08T05:57:09Z")
> [@popomomo\_cocoyoyo](#): > > This is weird cause I just read the exact opposite in the local free rag: [The strange ‘Oumuamua comet was not sent by aliens to save us](https://www.thestar.com/news/world/2018/11/06/the-strange-oumuamua-comet-was-not-sent-by-aliens-to-save-us.html). In other words, ‘It’s not aliens. It’s never aliens.’ ---
**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 8, 2018, 6:20am UTC](https://boards.straightdope.com/t/oumuamua-aliens/824062/38 "2018-11-08T06:20:05Z")
eschereal I’ve made similar comments, like can c change near a black hole. And I also got called a pink unicorn. Keep thinking…and fuck anyone who tells you to stop. ---
**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 8, 2018, 7:11am UTC](https://boards.straightdope.com/t/oumuamua-aliens/824062/39 "2018-11-08T07:11:02Z")
If no one has ever seen a pink unicorn, it stands to reason that they must be invisible. ---
**Author:** ![Miller](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/miller/32/481_2.png) [@Miller](https://boards.straightdope.com/u/Miller)\ **Post date:** [November 8, 2018, 8:04am UTC](https://boards.straightdope.com/t/oumuamua-aliens/824062/40 "2018-11-08T08:04:25Z")
> [@Darren\_Garrison](#): > > I’m basing the bolded part on that if the alien civilization had the miracle propulsion technology to allow a “cell phone sized object” to move from a hyperbolic to the sun course into one that intersected with the Earth (in any form other than a particularly bright meteor) they would have no need for something so primitive as a solar sail. Why would that require “miracle” propulsion? [Previous page](https://boards.straightdope.com/t/oumuamua-aliens/824062.md?page=1) [Next page](https://boards.straightdope.com/t/oumuamua-aliens/824062.md?page=3)