Breakthrough Listen Project to Observe Interstellar Object ‘Oumuamua | Hacker News Reader

Breakthrough Listen Project to Observe Interstellar Object ‘Oumuamua

breakthroughinitiatives.org

93 pointsandyjohnson055 comments

Some more details (besides the announcment) here for the curious https://www.theatlantic.com/science/archive/2017/12/yuri-mil...

It'd be crazy if we detected radio signals, in part because we don't really have a good way to send any probes fast enough to visit it closer as it speeds away from us, at least with current technologies. There's more on that here: https://arstechnica.com/science/2017/11/so-you-want-to-send-...

Well that depends on whether it slows down to have a listen before moving on, now doesn't it?? :)

If we detected radio signals I'd be all for a crash project to do so, possibly using NERVA or some similar kind of crazy propulsion system. A possible alien artifact would be absolutely worth the risk of launching a nuclear upper stage. Workable designs for NERVA are on the books. I'm sure we could think of some way to fire a very small probe at this thing by putting an absurd amount of rocket muscle behind it. Even a fast flyby with a few measurements and shots would be worth it.

I guess barring that we will soon have the JWST.

This. We have the technology to go this fast... but no pressing need. Should a pressing need arise I do not doubt we will begin immediately. SpaceX could be turning around Falcon Heavy after Falcon Heavy as we loft fuel tanks to a “probe” we assembled in orbit out of an existing space worthy hardware “core” capable of autonomous operation such as a Soyuz or Dragon capsule, any instrumentation could be just built as stand alone modules and bolted to a separate set of communication hardware. We could conceivably build a probe and chase this thing down to contact in under 5 years.

If it took 6 months to build (!!), could we go fast enough to catch up to it in a reasonable time?

Just thinking about this scenario is enough to give me goosebumps.

Imagine the alien probe about to leave the outer perimeter of our solar system while our makeshift-to-the-aliens probe is trying to catch up to it while detonating one nuke after another.

You'd think that would catch their attention.

"See look at that propulsion system! I told you they were f'ing crazy. Fire the engines again for another burn, quick. Let's get some distance before they figure out that you can create a quantum singularity and the whole solar system goes up." - the aliens

NERVA? nah. I'd probably go as far as getting the dust of the Project Orion and Medusa spacecraft. That's how you get there fast.

> “The more I study this object, the more unusual it appears, making me wonder whether it might be an artificially made probe which was sent by an alien civilization,” Avi Loeb, the chair of Harvard’s astronomy department and one of Milner’s advisers on Breakthrough Listen, wrote in the email to Milner.

It may sound silly, but I find it fascinating that we're finally in a time when someone in such high position in science can say such a thing without fearing ridicule. I'm also grateful that there are people wealthy enough to sponsor these scientific efforts. What an amazing time!

Why do you think he doesn't fear or risk ridicule by this statement.

I think he's bat-shit insane to make a mildly qualified statement like that.

The only reason we suspect that it is cigar-shaped is because its brightness changes (by a factor of about 10) with a somewhat regular frequency. But this indicates that it is tumbling, which would probably not be great for a ship designed with a long shape to reduce interstellar friction. Another potential (but less plausible) explanation is that it is not elongated and tumbling, but just blinking at us somehow.

Come on, it's obvious it's shaped like a penguin. The change in albedo is caused by the rotation needed to maintain gravity for the small alien penguins within.

Or that differing composition yields different albedo.

What if it's a wreck though? :)

Yeah - what if it has a distress beacon? Then we'd have to go!

Maybe we are just ignorant of the good interstellar friction reducing technology.

You're right tumbling could be just a technology... and even if we find out that it appears to be made out of rock and ice maybe we are just ignorant of interstellar materials technology!

"Oumuamua is now about 2 astronomical units (AU) away... At this distance, it would take under a minute for the Green Bank instrument to detect an omnidirectional transmitter with the power of a cellphone."

That's pretty impressive.

Shouldn't we have some much better pictures and a better idea of it's shape at that distance?

The thing is tiny, and that is very far.

This would be a possibly good way to learn we’re not alone in the universe. It’s clearly not staying around and thus not a threat. Just a simple “proof of existence”.

Edit-yes I’m aware the odds are surely small that it’s something like that. But just the same it wouldn’t be a bad way to learn of “others”.

Unless it released billions of MEMS which have started appropriating resources.

Small odds though :)

What an interesting idea.

Basis of The Expanse series.

oops. I think you just gave me a spoiler.

Not really, it's revealed pretty early.

> It’s clearly not staying around and thus not a threat. Just a simple “proof of existence”

Or a scout. You don't send your invasion/colonization fleet until you've got better intel.

I propose we call the object "Rama".

Seconded. They did say it was oddly rectangular/columnar.

This reads as if you're trying to draw a similarity between Oumuamua and Rama, but if that's the case, Rama was spherical, so I don't see the similarity. The only other thing I can think of is that the 2OO1(&) monolith was rectangular, but they never really moved IIRC.

(&): Sorry, screenreaders, but it's so much nicer with the letter 'o' rather than zeros :/

...no? It was cylindrical in the book.

Iirc, it was all cylindrical.

Holy crap. You're right! I read it back in February and must have consistently read "cylindrical" as "spherical" :o

I guess I should go back to see if the experience is better knowing the true shape...

For those who don't know, this is basically the plot of a classic science fiction novel, Rendezvous with Rama. (https://en.wikipedia.org/wiki/Rendezvous_with_Rama)

better than 2001.

I thought the commie Russians dated the novel when I read it in the 90s, but here we are, 2017, and everyone is worried about the Ruskies again. Funny ol world.

The sequels are pretty bad, by the way - Clarke eventually just started "co-writing" books where the other less-good writer did all the work. One of them has a foreword just so Gentry Lee can apologize he wrote a chapter about his historical hologram waifu.

I only made it a few chapters into the sequel, the writing is completely different and completely uninspiring.

Thanks, as some who hasn't grown up watching Hollywood or reading English sci-fi, I couldn't get the context.

Many of others like the name too: https://www.economist.com/news/science-and-technology/217308...

I was informed that its shape and rotation make it very unusual, in addition to being the first known interstellar object.

In our solar system, most small stuff has been rounded by billions of years of collisions. This may be a primeval shard from a high-energy collision in another solar system - unaffected because it was flung out of that system at high speed. Cosmic pointy shrapnel. :)

(Big stuff self-rounds per gravity, of course, but this ain't that big)

Relevant xkcd: https://xkcd.com/1919/

I read somewhere that this might be a spent first stage, and the real spacecraft is currently decelerating as it approaches our solar system. That would explain the shape, tumbling, and trajectory, but then again "weird space rock" explains those things more plausibly.

> this might be a spent first stage, and the real spacecraft is currently decelerating as it approaches our solar system. That would explain the shape, tumbling, and trajectory

I'm believing this until proved otherwise. I figure that would probably have the real ship arriving probably sometime in my old age, which would be perfect. Live to see the aliens, but close enough to death anyway in case things get ugly.

Far longer than old age, unless you plan on living a very long time. The thing was only moving a few 10’s of kilometers per second.

It's possible that the first stage was also used to decelerate a bit before being jettisoned, explaining the relatively low speed

Not that low a speed. Let’s say the generational ship was moving 0.01c, at the low end of what’s believable (500-1000 years to a nearby star). That means the ship was decelerated 99.999% of the way from cruise speed before jettisoned. In terms of energy, that’s 99.99999999% of the stopping thrust already expended. That’s without even getting into the rocket equation which makes it even worse.

At that point why not carry it into the system with you? The mass would be negligible given the energy budget. Ejecting it seems to serve no purpose but wasting several cubic kilometers of presumably processed material. Why do that?

Now maybe it was a probe ejected from a ship at distance, but then why is it tumbling end over end?

> I figure that would probably have the real ship arriving probably sometime in my old age

Why would that be? Shouldn't the mother ship be not far behind this, depending on how much they've decelerated since detaching?

If the ship is decelerating, then the second stage moves slower than the first stage.

But even if this was true, the second stage would already be here.

As the first stage goes at tens of kilometers per second and as we did not detected the second stage it is probably at more than a AU, so it will need more than a million seconds to reach earth, only more than 11 days, actually.

> If the ship is decelerating, then the second stage moves slower than the first stage.

Only if you fire the next stage. Otherwise there will be only what little velocity difference was created by detachment itself.

> But even if this was true, the second stage would already be here.

Not if it was used to decelerate further :).

I remember from reading about O'Neill cylinders that an object spinning on it's long axis will, under the influence of random perturbation, eventually start tumbling. So I'm wondering, if we take Oumuamua's angular momentum and figure out the rate of axial spin required to get the same angular momentum, do you get anything like earth-gravity equivalent centrifugal force near the surface of the object?

If it's 400 meters long and do one rotation in 7 hours the gravity is essentially zero. It'd have to rotate twice per minute to produce 1g.

Why earth gravity?

A question to the experts: Is it possible with current technology to send a probe after it? Let's say we decide today to do it and then spend the next 1-2 years to build a probe: would we still be able to catch up to it?

Several designs for propulsion systems capable of these accelerations with sufficient efficiency exist. These fall mostly into the region of nuclear drives such as NERVA or Project Orion/Medusa.

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