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Interstellar Comet 3I/Atlas: What We Know Now

skyandtelescope.org

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Re: Interstellar Comet 3I/Atlas: What We Know Now

#21

Post by pandemic_region »

kqgnkqgn wrote: post #20
EspadaV9 wrote: post #18

With the number of interstellar objects being detected only going up, it would be amazing if we could get some probes to hitch a ride on them. Imagine something lasting as long as Voyager 1 but travelling 3.5x the speed as it leaves the solar system.

Visiting one with a probe would surely be amazing in it's own right...but hitching a ride would mean matching velocities with them. And if you can do that...you're already in the same orbit, so the comet doesn't really help.

The comet having virtually unlimited fuel would be of great help.

Re: Interstellar Comet 3I/Atlas: What We Know Now

#22

Post by actionfromafar »

EspadaV9 wrote: post #18

With the number of interstellar objects being detected only going up, it would be amazing if we could get some probes to hitch a ride on them. Imagine something lasting as long as Voyager 1 but travelling 3.5x the speed as it leaves the solar system.

At first I thought, "no silly, it has to gain matching speed first, what's the point". Then it occurred to me - if we can make something which can survive the impact, we "just" have to place it in the path of the comet and it will be swept with it.

The whole thing would be like something like shooting a bullet at a moving target, but it's an idea.

That hypothetical probe will not look anything like any other space probe before it, but more like an artillery shell. (They can survive pretty damning Gs and still run that little embedded computer, so it's not a completely insane idea, I guess.)

We would also have to detect the interstaller object plenty in advance, so the probe can be launched "comfortably" in a trajectory which will intercept at exactly where the "object" is going to be.

Re: Interstellar Comet 3I/Atlas: What We Know Now

#23

Post by themgt »

kqgnkqgn wrote: post #20
EspadaV9 wrote: post #18

With the number of interstellar objects being detected only going up, it would be amazing if we could get some probes to hitch a ride on them. Imagine something lasting as long as Voyager 1 but travelling 3.5x the speed as it leaves the solar system.

Visiting one with a probe would surely be amazing in it's own right...but hitching a ride would mean matching velocities with them. And if you can do that...you're already in the same orbit, so the comet doesn't really help.

There's disposable FPV drones that launch with 50km spools of kevlar cable. Seems like smart people could work out a way to "hitch" a probe on a comet without fully matching velocities first.

Re: Interstellar Comet 3I/Atlas: What We Know Now

#24

Post by thegrim33 »

actionfromafar wrote: post #22
EspadaV9 wrote: post #18

With the number of interstellar objects being detected only going up, it would be amazing if we could get some probes to hitch a ride on them. Imagine something lasting as long as Voyager 1 but travelling 3.5x the speed as it leaves the solar system.

At first I thought, "no silly, it has to gain matching speed first, what's the point". Then it occurred to me - if we can make something which can survive the impact, we "just" have to place it in the path of the comet and it will be swept with it. The whole thing would be like something like shooting a bullet at a moving target, but it's an idea. That hypothetical probe will not look anything like any other space pr…

Some quick prompting seems to say a G force of somewhere between 16-160 billion Gs, for a CPU-equivalent object getting hit by a solid object moving at 3I's escape velocity. Compared to a "typical" artillery shell of 10-15 thousand Gs. Not sure you're manufacturing anything that could survive 6-7 orders of magnitude more Gs than an artillery shell.

Of course the G-load would lessen based on how much you sped up to match its speed beforehand, but still, I think you'd need to be pretty much sped up to near the same speed as it before you could remotely possibly survive the impact.

Re: Interstellar Comet 3I/Atlas: What We Know Now

#26

Post by bdamm »

pklausler wrote: post #7
supportengineer wrote: post #4

I'm inspired to re-watch Don't Look Up this afternoon.

At a closest approach of 1.8AU, you really don't have to worry about a collision with Earth. But that film is relevant to this comet in another way -- several missions that made it into space before the administration's war on the scientific enlightenment may be able to image the comet when we can't see it (perihelion) or when they're much closer to it than we'll ever be.

Do you happen to know which missions those might be?

Re: Interstellar Comet 3I/Atlas: What We Know Now

#27

Post by XorNot »

mathgeek wrote: post #15
unsupp0rted wrote: post #6

Could an object like 3I theoretically tell when eyes are being pointed at it? Probably not ground-based eyes, but possibly Hubble. i.e. "the inhabitants are scanning us"

Theoretically, any sentient being with the necessary technology to get a craft to our solar system and spot the aiming of a telescope at that distance would have even better technologies for detecting what we are doing.

It's a logistics problem: if you can build one of something, you can definitely build two.

Re: Interstellar Comet 3I/Atlas: What We Know Now

#28

Post by danparsonson »

pandemic_region wrote: post #21
kqgnkqgn wrote: post #20

Earlier quoted context omitted.

Visiting one with a probe would surely be amazing in it's own right...but hitching a ride would mean matching velocities with them. And if you can do that...you're already in the same orbit, so the comet doesn't really help.

The comet having virtually unlimited fuel would be of great help.

No it wouldn't because once you've matched speed with it, you stop accelerating and therefore need no more fuel. The comet isn't doing anything except following gravity.

Re: Interstellar Comet 3I/Atlas: What We Know Now

#29

Post by signa11 »

kqgnkqgn wrote: post #20
EspadaV9 wrote: post #18

With the number of interstellar objects being detected only going up, it would be amazing if we could get some probes to hitch a ride on them. Imagine something lasting as long as Voyager 1 but travelling 3.5x the speed as it leaves the solar system.

Visiting one with a probe would surely be amazing in it's own right...but hitching a ride would mean matching velocities with them. And if you can do that...you're already in the same orbit, so the comet doesn't really help.

matching velocities till you can hitch the ride. from that point onwards, you can just do…nothing (at least in that department)

Re: Interstellar Comet 3I/Atlas: What We Know Now

#30

Post by actionfromafar »

thegrim33 wrote: post #24
actionfromafar wrote: post #22

Earlier quoted context omitted.

At first I thought, "no silly, it has to gain matching speed first, what's the point". Then it occurred to me - if we can make something which can survive the impact, we "just" have to place it in the path of the comet and it will be swept with it. The whole thing would be like something like shooting a bullet at a moving target, but it's an idea. That hypothetical probe will not look anything like any other space pr…

Some quick prompting seems to say a G force of somewhere between 16-160 billion Gs, for a CPU-equivalent object getting hit by a solid object moving at 3I's escape velocity. Compared to a "typical" artillery shell of 10-15 thousand Gs. Not sure you're manufacturing anything that could survive 6-7 orders of magnitude more Gs than an artillery shell. Of course the G-load would lessen based on how much you sped up to ma…

Wow, I clearly didn't think this through. That's brutal.

That leads to another idea - if something more substantial was placed in its path - the resulting debris and gas cloud from the impact could reveal something about the contents of the object.

Or, if it's an alien probe, it would force their hand. :-D We could see some exotic manuevering.

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