Interview with the astronomer who speculated that Oumuamua might be a sign of extraterrestrial life


Originally published at:


I always got the impression it was a bit of a “just spitballing theory” - no evidence against now, but almost certainly disprovable… but hey it generates buzz so why not be “that guy” and posit it?


I still go with a giant space poop, yeah, that’s what it is.


Scientists are actually having a very difficult time explaining how the object could be natural. There’s a lot of great discussion going on elsewhere, one such example:

There are a number of people speculating that due to the way it accelerated, the lack of out-gassing and the weird rotation and albedo that a possible explanation is a light-sail, which is pretty crazy to think about. Also, it’s speed was pretty much exactly the local standard of rest, which means we went blowing past it, not vice versa. Obviously it’s all speculation and there’s no way we’re going to catch up to the thing and check, but still very cool.




A light sail that can move a rock that size would be many kilometers wide and easily spotted, right?


The size of the rock is purely speculative based on reflected light, apparently a light sail better explains the reflectivity and the acceleration and it would be much smaller.


But then the sail is less than a kilometer wide, which would be tiny. The payload would be very small indeed.


i’m cautiously optimistic that it contains intelligent life, who will jettison off in a smaller craft and slam it into us :wink:


wow it’s a relief to find an honest conversation on the internet.


possibly technological flotsam or wreckage


what’s more important is how you use it




It’s going to be within the bounds of our Solar System for the next 20,000 years, so still plenty of time to catch up with it at some point.

(And yes, I know that’s a completely arbitrary limit for the purposes of argument, but Douglas Adams, space is big etc.)



"He made this argument in a scientific paper published on the 12th of this month, … "

There’s probably more stuff he knows that we don’t.


Its deeply unfortunate how many “ancient astronaut” and “flying saucer” charlatans we have to wade through before there’s some scientifically rigorous, reasonably measured… speculation. SETI itself is pretty speculative, and those guys are inundated with this bullshit.

Most of the time it seems harmless, but its not that far removed from the bullshit that bought us Donald Trump, so I have begun to take it more personally.


The interviewer uses “galaxy” when he means “solar system”, and his distinguished astronomer guest doesn’t even call him on it.

And now I want to set fire to everything.

UPDATE: OK, having listened to the whole thing all the way through, it’s generally very good – well-presented, well-paced and interesting. I did find the conclusion “if this phenomenon turns out to be very unusual, it implies purposeful activity” (slightly paraphrased) to be questionable – it’s too much like ‘intelligent design’ thinking for me to be comfortable with it. But overall, it was a very interesting topic covered very well. 10/10, would pod-listen again.


Earlier in the podcast he talks about the Breakthrough Starshot project, and describes laser-powered lightsails with a 1-meter diameter, moving a 1g payload – tiny indeed, but still able to do some useful science (especially if you have a coordinated swarm of them). A kilometer-wide lightsail might have a payload in the 100-1000g range, which is still pretty small but, depending on what you put into it, still potentially interesting.


It is far too much like the “God in the Gaps” argument. “We don’t have an explanation, therefore we go with the most fanciful and unlikely one”