Nearby Star Forecast To Skirt Solar System 135
PipianJ writes "A recent preprint posted on arXiv by Vadim Bobylev presents some startling new numbers about a future close pass of one of our stellar neighbors. Based on studies of the Hipparcos catalog, Bobylev suggests that the nearby orange dwarf Gliese 710 has an 86% chance of skirting the outer bounds of the Solar System and the hypothesized Oort Cloud in the next 1.5 million years. As the Oort Cloud is thought to be the source of many long-period comets, the gravitational effects of Gliese's passing could send a shower of comets into the inner Solar System, threatening Earth. This news about Gliese 710 isn't exactly new, but it's one of the first times the probability of this near-miss has been quantified."
Re:So.... (Score:3, Interesting)
Re:So.... (Score:1, Interesting)
So, in 1.5 million years we might possibly be threatened by some comets? Something tells me that unless we do something incredibly SMART in the next 1.5 million years, a lot of humanity isn't going to be on earth. So, in short, how is this news? I don't think anyone is going to be around in 1.5 million years.
There, Fixed that for you.
You're assuming that humanity will last the next 500 :P
Re:In 1.5 Million Years... (Score:1, Interesting)
You joke, but it would probably take 1.5 million years to develop a technology that is capable of diverting or destroying a star.
H. G. Wells, 1911 (Score:5, Interesting)
H. G. Wells, "The Star" (1911) [gutenberg.org]
It was on the first day of the New Year that the announcement was made, almost simultaneously from three observatories, that the motion of the planet Neptune, the outermost of all the planets that wheel about the sun, had become very erratic....
Beyond the orbit of Neptune there is space, vacant so far as human observation has penetrated, without warmth or light or sound, blank emptiness, for twenty million times a million miles. That is the smallest estimate of the distance to be traversed before the very nearest of the stars is attained. And, saving a few comets more unsubstantial than the thinnest flame, no matter had ever to human knowledge crossed this gulf of space, until early in the twentieth century this strange wanderer appeared....
On the third day of the new year the newspaper readers of two hemispheres were made aware for the first time of the real importance of this unusual apparition in the heavens. "A Planetary Collision," one London paper headed the news, and proclaimed Duchaine's opinion that this strange new planet would probably collide with Neptune....
And when next it rose over Europe everywhere were crowds of watchers on hilly slopes, on house-roofs, in open spaces, staring eastward for the rising of the great new star. It rose with a white glow in front of it, like the glare of a white fire, and those who had seen it come into existence the night before cried out at the sight of it. "It is larger," they cried. "It is brighter!" And, indeed the moon a quarter full and sinking in the west was in its apparent size beyond comparison, but scarcely in all its breadth had it as much brightness now as the little circle of the strange new star.
"It is brighter!" cried the people clustering in the streets. But in the dim observatories the watchers held their
breath and peered at one another. "_It is nearer_," they said. "_Nearer!_"
[Most of the story tells of how star approaches close to Earth, creating considerable havoc...]
But the star had passed, and men, hunger-driven and gathering courage only slowly, might creep back to their ruined cities, buried granaries, and sodden fields. Such few ships as had escaped the storms of that time came stunned and shattered and sounding their way cautiously through the new marks and shoals of once familiar ports....
The Martian astronomers--for there are astronomers on Mars, although they are very different beings from men--were naturally profoundly interested by these things. They saw them from their own standpoint of course. "Considering the mass and temperature of the missile that was flung through our solar system into the sun," one wrote, "it is astonishing what a little damage the earth, which it missed so narrowly, has sustained. All the familiar continental markings and the masses of the seas remain intact, and indeed the only difference seems to be a shrinkage of the white discoloration (supposed to be frozen water) round either pole." Which only shows how small the vastest of human catastrophes may seem, at a distance of a few million miles.
This is an opportunity, not a threat! (Score:3, Interesting)
Providing that humanity still exists in the year 1.5M but hasn't yet spread to other solar systems, this is a huge opportunity: Rather than needing to travel 3-4 light years in order to reach another star, we'll need to travel less than one light year -- thus making the trip both faster and much cheaper.
Who knows, it might even be possible to slowly spread across the entire galaxy without ever venturing into interstellar space.
Re:So.... (Score:3, Interesting)
With the huge size of the 1.5 million number, it's all moot anyway, but if we haven't figured out a way out of the solar system by then, it seems like a great way to hitch a ride with the rogue star. Sure, it's much weaker than the sun, but if by then we have the technology to park a couple of space stations or asteroids that much closer to it, seems like a great way to do extra-solar colonization on the cheap.
Re:Nations are the wrong tools for this time scale (Score:4, Interesting)
I know there's a lot of work ahead of us. And I realize that "canned monkeys" aren't enough. But the big point is, real colonization has to start somewhere--ie, with lots of canned monkeys and solar-power satellites. Too many people want to sit around saying that all of this is too hard, that it isn't practical without advanced technologies that we don't currently have, and then decide "well, we can't do it right now, so why bother trying?" They conveniently forget that all of this Buck Rogers takes effort, not just bucks. Someone has to work on them; they don't just fall out of the sky ready to go. We're fooled by seeing all of these different advances in different fields (like computing), forgetting that the progress is happening because, well, somebody is doing the work. It just happens that most of that work can be applied to other fields. But things like nuclear space propulsion and vacuum-rated hardware don't have lots of other applications, and unless someone in the aerospace field works on them, unless somebody puts money towards them, they'll stagnate. We'll sit there forever wondering why we don't have all these fancy things, and yet never actually get them.
I mean, we didn't sit there after the Wright brothers flew and decide that pursuing airplanes was a worthless endeavor, that we should just wait until we could build the 787, did we? Well, that's what we're doing with space. We've taken our first baby step, then given up on trying to walk because we can't yet run a marathon. Maybe we won't make it out into space before we manage to kill ourselves off... but I, for one, would rather go down fighting. And if that does happen, if we do die off and exist no more, then everything we've ever done in the name of progress and benefiting humanity, everything every person ever did, will be for naught.
Re:So.... (Score:3, Interesting)
I sort-of agree, but you've got to do things in the right order. First step should be an almost closed life-support system. That still needs a *lot* of work. Some things can be done in parallel, but at the moment that looks like the rate limiting step. (And besides, advances in robotics and waldos might eliminate a lot of the problems. E.g., a good space-suit might not need direct connections to arms, fingers, etc. if that could be managed via wi-fi or some such.)
To me it appears that the rate limiting steps are:
1) almost closed life-support. (Presume that energy inputs in the form of electricity are allowed, but material inputs are strictly limited.)
2) how should solar storms be handled? 3 feet of lead+3 feet of paraffin would probably work, but that's a bit of a heavy shield.
3) mining carbonaceous chondrites for air and water replacements. (I said the life support was almost closed. That means you need supplements to actually close it.)
4) solving long-term life without gravity. (This is probably a biological problem, though a large spinning construction would also work. At least as a stop-gap.)
5) NOW one can talk about a long-term colony. That means that at this point one can start fine-tuning the sociology to create a stable or quasi-stable civilization existing in the environment of space.
So at the moment there's not much the average person can do. Supporting space-based research is good. Supporting robotics is good. Supporting space-enthusiast societies is good. But expecting any particular result in the next decade is unwise.
N.B.: The energetics of space colonies aren't properly dealt with by science fictions stories...ANY of them. Asteroids have orbits that are skew to each other (often not by a lot, but it doesn't take a lot to make transport between them unreasonably expensive). Even so, if you notice, Larry Niven presumed that the space ships used by the belters used hydrogen fusion jets. That's probably not energetic enough, but he was vague enough about how much fuel was used that "perhaps". He did presume that the ships could accelerate at several Gs for extended periods of time.
More practical is a civilization based around exchange of messages with little exchange of physical media. That doesn't require technologies like hydrogen fusion powered torches (rockets).
N.B.: The further out you get from the sun, the more skew the orbits of the satellites (planets, asteroids, etc.) are. So the more energy intensive it is to get from one to another. It would often be cheaper to get into high earth orbit than to match to something with a widely skew orbit.
P.S.: This argument doesn't really apply to trojan points. Things orbiting in trojan points should have easy transitions from one to another. But that's a small fraction of the asteroids.