<p>Dr. Avi Loeb, the distinguished astrophysicist and chair of Harvard's Astronomy Program, just published a book called <a href="https://rads.stackoverflow.com/amzn/click/com/0358278147" rel="noreferrer" rel="nofollow noreferrer">Extraterrestrial: The First Sign of Intelligent Life Beyond Earth</a>.</p>
<p>In the book, Dr. Loeb calls out several specific peculiarities about the interstellar object <a href="https://en.wikipedia.org/wiki/%CA%BBOumuamua" rel="noreferrer">Oumuamua</a>. He proposes a rather shocking hypothesis:</p>
<blockquote>
<p>I submit that the simplest explanation for these peculiarities is that
the object was created by an intelligent civilization not of this
Earth.</p>
</blockquote>
<p>In interviews <a href="https://www.sciencefriday.com/segments/avi-loeb-extraterrestrial-life/" rel="noreferrer">1</a>, <a href="https://www.newyorker.com/news/q-and-a/have-aliens-found-us-a-harvard-astronomer-on-the-mysterious-interstellar-object-oumuamua" rel="noreferrer">2</a>, <a href="https://nypost.com/2021/01/02/a-harvard-professor-says-an-alien-visited-in-2017/" rel="noreferrer">3</a>: Dr. Loeb mentions several peculiarities.  Here are three:</p>
<ol>
<li><p>Oumuamua has a unique light curve.  Uhoh has a nice analysis and some great graphics in this answer: <a href="https://astronomy.stackexchange.com/questions/23620/could-asteroid-oumuamua-actually-be-round/23627#23627">Could asteroid &#39;Oumuamua actually be round?</a>. Dr. Loeb claims that the high aspect ratio implies this is not a natural object. He uses an analogy of a thin piece of paper falling through the air having a less extreme aspect ratio.</p>
</li>
<li><p>Oumuamua showed acceleration <a href="https://www.scientificamerican.com/article/mystery-of-interstellar-visitor-oumuamua-gets-trickier/" rel="noreferrer">unaccounted for by orbital mechanics</a> after its close pass to the Sun similar to a comet.  A comet gets its push due to evaporation of gasses, but there was no evidence that Oumuamua had a tail of gas.  Dr. Loeb proposes that Oumuamua may have been designed as a light sail.</p>
</li>
<li><p>Dr. Loeb claims Oumuamua's velocity as it entered the Solar System is <a href="https://blogs.scientificamerican.com/observations/6-strange-facts-about-the-interstellar-visitor-oumuamua/" rel="noreferrer">slower than 1 out of 500 near star systems</a> in an LSR reference frame.</p>
</li>
</ol>
<p><strong>Does the evidence support Dr. Loeb's hypothesis that Oumuamua is most likely of extra-terrestrial origin?</strong></p>

CC BY-SA 4.0
2021-01-27T19:33:42.793Z
I think you have posed this question well in a way that makes clear it is on topic. However, I am not sure we can really make a satisfactory answer to this here. Dr. Loeb's publications are still relatively new and I feel like any answer here wouldn't be better than a single paper by another scientist--and likely less reliable than that.
called2voyage
CC BY-SA 4.0
2021-01-27T20:05:16.013Z
I suggest watching this video from Dr. Kippling. It explains fairly the current state of the debate. Spoiler: Avi Loeb is extremely optimistic and is making a wild statement here, even if speculatively productive https://www.youtube.com/watch?v=qX_Bj7064Ms
Swike
CC BY-SA 4.0
2021-01-27T20:11:57.080Z
@called2voyage Perhaps you are correct, but I don't think we should shy away from questions that are difficult or even taboo in astronomy.  Not that you were suggesting we do so, of course.
Connor Garcia
CC BY-SA 4.0
2021-01-27T20:17:27.700Z
I would contend that anyone who thinks the most logical explanation for anything (in space) that isn't man-made is that it's alien-made simply doesn't understand how vastly, hugely, mindbogglingly big space is (and how complex nature is).
zibadawa timmy
CC BY-SA 4.0
2021-01-27T20:19:15.807Z
@swike I am hoping one of our "heavy hitters" like yourself, ProfRob, or Uhoh will pose an answer to this question.  We can guess that Dr. Loeb's motive is in part to de-stigmatize and promote more SETI research, but is his hypothesis supported by the evidence?
Connor Garcia
CC BY-SA 4.0
2021-01-27T23:15:34.713Z
Pieces of paper in space seem unreasonable even if made of silicates.  We saw something odd. It is not the first time that's happened.
Wayfaring Stranger
CC BY-SA 4.0
2021-01-28T05:53:10.180Z
Please, why the downvote?
Connor Garcia
CC BY-SA 4.0
2021-12-21T21:26:40.107Z
The more outrageous the claim, the more demanding the need for supporting evidence.
Clearly Oumuamua is of extra-terrestrial origin (it's from off of the Earth, after all), but that doesn't mean that it was created, modified, or directed by an alien intelligence.  If it were, they'd have to be either a) very, very close to us already or b) lived so long ago that they've (probably) already died out.  Even at speeds as fast as we detected it, it would still have taken thousands of years to get here from Alpha Cen.
GrasshopperTaji
<orbital-mechanics><extra-terrestrial><oumuamua>
Did Aliens make Oumuamua?
Connor Garcia
# Did Aliens make Oumuamua?

(Asked by: username_0 on 2021-01-27)

Dr. Avi Loeb, the distinguished astrophysicist and chair of Harvard's Astronomy Program, just published a book called [Extraterrestrial: The First Sign of Intelligent Life Beyond Earth](https://rads.stackoverflow.com/amzn/click/com/0358278147).

In the book, Dr. Loeb calls out several specific peculiarities about the interstellar object [Oumuamua](https://en.wikipedia.org/wiki/%CA%BBOumuamua). He proposes a rather shocking hypothesis:

> I submit that the simplest explanation for these peculiarities is that
> the object was created by an intelligent civilization not of this
> Earth.

In interviews [1](https://www.sciencefriday.com/segments/avi-loeb-extraterrestrial-life/), [2](https://www.newyorker.com/news/q-and-a/have-aliens-found-us-a-harvard-astronomer-on-the-mysterious-interstellar-object-oumuamua), [3](https://nypost.com/2021/01/02/a-harvard-professor-says-an-alien-visited-in-2017/): Dr. Loeb mentions several peculiarities. Here are three:

1. Oumuamua has a unique light curve. Uhoh has a nice analysis and some great graphics in this answer: [Could asteroid 'Oumuamua actually be round?](https://astronomy.stackexchange.com/questions/23620/could-asteroid-oumuamua-actually-be-round/23627#23627). Dr. Loeb claims that the high aspect ratio implies this is not a natural object. He uses an analogy of a thin piece of paper falling through the air having a less extreme aspect ratio.
2. Oumuamua showed acceleration [unaccounted for by orbital mechanics](https://www.scientificamerican.com/article/mystery-of-interstellar-visitor-oumuamua-gets-trickier/) after its close pass to the Sun similar to a comet. A comet gets its push due to evaporation of gasses, but there was no evidence that Oumuamua had a tail of gas. Dr. Loeb proposes that Oumuamua may have been designed as a light sail.
3. Dr. Loeb claims Oumuamua's velocity as it entered the Solar System is [slower than 1 out of 500 near star systems](https://blogs.scientificamerican.com/observations/6-strange-facts-about-the-interstellar-visitor-oumuamua/) in an LSR reference frame.

**Does the evidence support Dr. Loeb's hypothesis that Oumuamua is most likely of extra-terrestrial origin?**

**Tags:** orbital-mechanics, extra-terrestrial, oumuamua

> **Comments:**
> **username_1**: I think you have posed this question well in a way that makes clear it is on topic. However, I am not sure we can really make a satisfactory answer to this here. Dr. Loeb's publications are still relatively new and I feel like any answer here wouldn't be better than a single paper by another scientist--and likely less reliable than that.  
> **username_2**: I suggest watching this video from Dr. Kippling. It explains fairly the current state of the debate. Spoiler: Avi Loeb is extremely optimistic and is making a wild statement here, even if speculatively productive https://www.youtube.com/watch?v=qX_Bj7064Ms  
> **username_0**: @username_1 Perhaps you are correct, but I don't think we should shy away from questions that are difficult or even taboo in astronomy.  Not that you were suggesting we do so, of course.  
> **username_3**: I would contend that anyone who thinks the most logical explanation for anything (in space) that isn't man-made is that it's alien-made simply doesn't understand how vastly, hugely, mindbogglingly big space is (and how complex nature is).  
> **username_0**: @username_2 I am hoping one of our "heavy hitters" like yourself, ProfRob, or Uhoh will pose an answer to this question.  We can guess that Dr. Loeb's motive is in part to de-stigmatize and promote more SETI research, but is his hypothesis supported by the evidence?  
> **username_4**: Pieces of paper in space seem unreasonable even if made of silicates.  We saw something odd. It is not the first time that's happened.  
> **username_0**: Please, why the downvote?  
> **username_5**: The more outrageous the claim, the more demanding the need for supporting evidence. Clearly Oumuamua is of extra-terrestrial origin (it's from off of the Earth, after all), but that doesn't mean that it was created, modified, or directed by an alien intelligence.  If it were, they'd have to be either a) very, very close to us already or b) lived so long ago that they've (probably) already died out.  Even at speeds as fast as we detected it, it would still have taken thousands of years to get here from Alpha Cen.  

---

## 0 answers

