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Another Interstellar ‘Visitor’ Is Headed Our Way
- bjelkeman-again 7y agoSo imagine it was actually Rama (I1, Oumuamua) and Rama II (I2). We’d be sitting here watching them zip by and not be able to do anything other than watch longingly at them. I suppose we’d get a perspective change on life in the Universe. Maybe it would increase space budgets.
- arethuza 7y agoESA is planning a "Comet Interceptor" mission that will loiter at the Sun-Earth L2 point for up to three years for something reachable to fly-by: https://en.wikipedia.org/wiki/Comet_Interceptor https://en.wikipedia.org/wiki/Comet_Interceptor Maybe a few more probes like this in suitable locations would give us a better chance of intercepting interesting stuff passing through the solar system.
- sandworm101 7y agoAs a general rule, having an interceptor already in an orbit is slower than launching a new one. If the target is coming in on a random orbit, the interceptor floating off in space is in no better a position, on average, than earth. So it is generally more efficient to launch from earth into a more targeted orbit than redirect a craft already in a less-than-ideal position. That said, having dozens or hundreds of probes in random orbits would be advantageous, but still much more costly.
- rtkwe 7y agoMaybe faster to reach it but accounting for prep times to ready the probe and rocket the equation probably changes. L1-3 are actually pretty good spots for it though because they're unstable and small perturbations will drastically change the orbit. Parking one is also predictable in budgets where a random emergency launch isn't and will cost more than a planned launch just to get things done quickly.
- sandworm101 7y agoThe L points are 'easier' but not any faster. A probe at an L point won't be able to get anywhere any faster than if it were launched from earth directly[1]. And sending a probe on a rocket to park itself at an L point wastes delta-v, as opposed to launching the same rocket directly from earth to the target. [1] Excepting maybe a target that appears conveniently a the same L point.
- jandrese 7y agoThe point is that you can't leave a rocket on the pad fueled and ready to go 24/7/365 because those pads are in use for other rockets and keeping them ready to fly is fairly labor intensive. So the advantage of already being in orbit is that you don't have to go through all of the logistics of getting the rocket to the pad, prepping it for flight, getting launch permission, etc... That's a difference of a couple of weeks.
- HarryHirsch 7y agoHere's a silly thought: why can't we put the spacecraft on top of an ICBM in a silo and launch when the next extrasolar object is detected? The American and Russian armed forces worked out 24/7 launch readiness in the 1960s.
- jandrese 7y agoNobody wants to pay for the personal needed to staff that silo.
- sandworm101 7y agoBecause an ICBM doesn't have anywhere near the power needed for such a mission. A timely flyby of an interstellar object would need something akin to the Saturn-V or Falcon Heavy, or perhaps multiple launches of said. An ICBM is a firecracker in comparison.
- 7y ago
- jerf 7y agoYou can't intercept an interstellar object from a loitering orbit around the sun, with something that has basically zero delta-v (in terms of this context) onboard. The loitering orbit, by necessity, has a fairly tightly constrained velocity vector, and the interstellar object, by virtue of having escape velocity from our sun, must have a much higher velocity vector by a certain large number of kilometers per second at a minimum, basically unbounded on the upper end. By the time you have something like a nuclear rocket in space that has the requisite delta-v, there becomes no particular reason to station it around the sun, since you can get to the right vectors from anywhere in the system.
- PopeDotNinja 7y agoI was wondering how the Comet Interceptor could accelerate to follow the same path as some comet thing. The short answer is https://en.wikipedia.org/wiki/Solar_electric_propulsion https://en.wikipedia.org/wiki/Solar_electric_propulsion. It's a pretty cool technology in space, but you wouldn't want to use it for your commute to work here on Earth.
- tomp 7y agoI'm guessing from this book? https://en.wikipedia.org/wiki/Rama_II_(novel) https://en.wikipedia.org/wiki/Rama_II_(novel)
- chowells 7y agoEh. The first one, Rendezvous with Rama, was a lot better in my opinion: https://en.wikipedia.org/wiki/Rendezvous_with_Rama https://en.wikipedia.org/wiki/Rendezvous_with_Rama
- cgriswald 7y agoIf I were designing Rama, I’d probably make the craft change directory and/or slow down on entry into a star system. This would indicate its artificial nature, give inhabitants a better chance at intercept, and protect it from collision.
- magduf 7y ago>I’d probably make the craft change directory How do you know that the ETs use a hierarchical filesystem?
- interfixus 7y agoThe Ramans do everything in trees.
- aiyodev 7y agoI really appreciate this joke. Good job.
- SECProto 7y agoSlowing down or changing direction (in space) is equally as much work as accelerating the craft in the first place.
- tiborsaas 7y agoOf course! We should put some speed limit and CCTV warning signs at the orbit of Pluto :) But on the serious note why would you do that if your mission is only observation, data collection or maybe launching micro probes?
- elorant 7y agoIf you are an alien civilization with interstellar capabilities why risk a fly by from a planetary system which could easily be detected, or even intercepted, even by less advanced beings instead of just park a probe in the outskirts of the Solar system and collect as much data as you like undetected. If then again Oumuamua was a probe traveling for millennia in search for alien life then there's no point of sending two in the same planetary system.
- cr0sh 7y agoI'm not saying it was - but what if Oumuamua was some kind of "derelict" - an intergalactic equivalent of the "Mary Celeste" - a ghost ship from deep space? Imagine a civilization that is maybe 500 years more advanced than ours in space travel - perhaps they have nearly conquered their solar system. Instead of building ships the regular way, they instead carve up asteroids or other similar "space rocks" and attach engines to them in some way. But something went wrong - maybe the engines got stuck "on" or something, and the entire thing was launched out beyond their system, never to be seen by them again... ...and it floated for however many of our millenia before briefly tumbling through our system. To us, it looks like a rock - we can't even optically resolve it properly, it's too fast and too far away. In (fantasy) reality, though, on board is a bunch of technology that we could probably understand, that would allow us to "leap" to hands-on human exploration (and exploitation) of our own solar system. It might be both a blessing and a curse. Again - sheer fantasy - and most likely it was just a shard of rock and nothing more. But is it far fetched to think that there isn't "large scale" ships or probes of some nature just drifting through space, probably completely broken down and relatively inert, moving at sub-light speeds due to various reasons, but made out of rock because it's easy to get, provides relatively good protection from space, easy to modify, etc? We humans have already flung tiny objects out of our solar system - I can believe that larger artifacts might be something that could "drift away" as well (then again, one would think that if a civilization got to that level - they'd be able to go out and retrieve it before it got too far away). Maybe it'd make a good science fiction story - from both ends (the creation of the "ship", the "loss" after trying to retrieve it, then the journey and the eventual discovery of it by another civilization "far away" - and how it changes the discoverers socially, politically, and technologically).
- sandworm101 7y agoIf we can see them, we can study them. We could aim radars at them to image their size/shape. We could aim lasers at them to study their surfaces. We could measure any impacts they have on magnetic fields or the solar wind, perhaps giving us insight into their means of propulsion. Sin short, if we are ready there is much that can be done short of physical contact. The real question is whether we would want to take such risks.
- mc32 7y agoYes, another inanimate “visitor”. What’s with these headlines? It just doesn’t stop.
- rmilejczz 7y agoThe first sentence of this article calls this object a comet, and the article goes on to discuss whether this comet is of interstellar origin or not based on the eccentricity of its orbit. It’s a good article that isn’t about aliens, and it’s really not all that long.
- spuz 7y agoWhat do you mean?
- captn3m0 7y agoIt’s a rock.
- PhasmaFelis 7y agoA rock can be a visitor. Figurative language exists.
- The_rationalist 7y agoIt introduce slightly harmful ambiguity for no other reason than clickbait.
- xena 7y agoIt's almost like clickbait pays the bills or something
- penagwin 7y agoI see the reason that it could be seen as click bait, but given the context I don't think many people on HN will think it was animate. It also says "another", and since we haven't been visited by life before it would suggest they meant it more as "this thing will visit us, thus it's a 'visitor'"
- mxuribe 7y agoHearing about things like this is so inspirational for me. Such a wondrous thing to behold! Kudos to Gennady Borisov!
- aey 7y agoHow is this possible? If space outside the solar system is empty, then the probability of 2 extrasolar comets should be 0 during my lifetime.
- rebolek 7y agoWhy should it be empty?
- slantaclaus 7y agoYeah who said it was empty?
- penagwin 7y ago> If space outside the solar system is empty, Empty? You've seen stars in the night sky before surely?
- chousuke 7y agoThe space outside the solar system is mostly empty, but also really big. Maybe these things are more common than we think. Rare events also happen all the time; something being extremely improbable doesn't mean it will never happen.
- mcbits 7y agoIt's possible because "empty" is a relative term and the solar system is big. Hell, a whole 'nother star system passed through the solar system (if we include the Oort cloud) just 1,000 lifetimes ago. https://en.wikipedia.org/wiki/Scholz%27s_Star https://en.wikipedia.org/wiki/Scholz%27s_Star
- GuiA 7y agoMan, it’s pretty crazy that it passed in the solar system, but its peak apparent magnitude was 11. Space is weird.
- aaron695 7y ago> If space outside the solar system is empty, then the probability of 2 extrasolar comets should be 0 during my lifetime. Your life time is a blip, approx 0 time units long. So it's either hourly or more, there might be thousands of various sizes each day for instance. Or these are fake news. Old bits of junk coming back. People are finding oddities in the massive amount of space debris and claiming they are something else. But yea, these are not explained properly. The story is missing the logic part. Which to me means it's probably option 2.
- api 7y agoMy favorite wild hypothesis about Oumuamua is that it was a spent deceleration stage from a multi-stage interstellar fusion rocket. Maybe another spent stage is headed our way. If it's at a lower velocity it would support that conjecture. Eventually the actual payload would arrive. :)
- SketchySeaBeast 7y agoWhile that's a fun hypothesis, I think we should remain objective and assume it's probably just a space rock. I mean, in that case you could also assume it's the excreta of some sort of high energy projectile that is currently aligned to collide with Earth, but that doesn't buy us much more than unfounded dread.
- api 7y agoIf it were an interstellar kinetic weapon it would not be decelerating, as the goal would be to smash us with as much kinetic energy as possible. :)
- SketchySeaBeast 7y agoOh no, that was a piece of the guidance material, used to redirect the weapon. You wouldn't take a shot from 400 light years without wanting the ability to curve the bullet a bit.
- api 7y agoWell that would explain the Fermi Para... <kaboom> ... ... ...
- jschwartzi 7y agoSorry, it's not a weapon. It's just a molecule designed to hijack self-replication to construct a wormhole generator.
- 7y ago
- alaithea 7y agoIf you didn't read all the way down, this was one of the coolest parts: > Here's an amazing fact: The discoverer, Gennady Borisov, is an amateur astronomer who works as an engineer at the Sternberg Astronomical Institute. He makes his own telescopes to hunt for comets and has discovered seven of them along with several NEOs. He recently completed a new 0.65-meter telescope, the instrument he used to discover the new object.
- imhoguy 7y agoAnd the other cool thing is the comet publicly named after himself https://en.m.wikipedia.org/wiki/C/2019_Q4_(Borisov) https://en.m.wikipedia.org/wiki/C/2019_Q4_(Borisov) Great hobby!
- Dirlewanger 7y agoMakes me wonder what other objects passed by us eons ago, and then due to other objects far out in their orbit that disrupted them just enough so that the next time they come our way, they're on a collision course with Earth...