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Possible Habitable Planet Just 12 Light Years Away
sciencehabit writes "Astronomers have discovered what may be five planets orbiting Tau Ceti, the closest single star beyond our solar system whose temperature and luminosity nearly match the sun's. If the planets are there, one of them is about the right distance from the star to sport mild temperatures, oceans of liquid water, and even life (paper)."
I've got my own helmet. Where do I sign up?
plop
When you're talking about interstellar distances "Just" is an appropriate term to put in front of a distance as small as 12 light years. At our current space flight capabilities it would take us ages to get there. How ever 12 light years is do able, in terms of physics and engineering. We would have to be willing to commit to a very serious project to build the ship though and I don't foresee any government willing to do that in the near future.
Even if the planets are inside the habitable zone, they would need to be the correct consistencies... Venus and Mars are in the zone here, but neither has life or is natively habitable. Yes, we're attempting to discover if Mars may have HAD life, but as far as we can obviously tell, it has none now...
So it's fun and interesting to search these types of star systems and planets--and I think it's absolutely worthwhile to focus a SETI program on them to try to determine if there are any stray signals we can pick up--but otherwise this really is not much more than dreaming and guessing.
Assuming SETI finds no signals, but we do believe there a couple of planets into the habitable zone, then I think it would make some sense to attempt a probe mission there... but it could be a while before we're at the technology level we'd need...
I think our current speed record in space is about 150,000mph ... which is ~1/5000th the speed of light. So while 12 years seems do-able from a speed of light point of view, there is no (present) method to send a probe there in a reasonable amount of time... I'd say reasonable would be a ~36 years to get there, plus another 12 years for the return signal... so roughly 50 years from launch to first data... meaning it would likely be a two, maybe three, generation program from a NASA engineer point of view.
We'd need something capable of:
a) Traveling at least 1/3rd the speed of light (roughly a quarter billion miles per hour)
b) A power source capable of lasting at least ~40 years or more with enough juice available near end of life to complete its mission
c) Capable of complete autonomy in 100% unknown situation
d) Possibly requiring the ability to actively correct its course en route, and maybe even detect and avoid collisions
Just send a B Ship full of your Republicans, climate denialists, gun nuts and all the other right-wingers around the world.
They can propel themselves there with bombastic hot air, and they'll fuck everything up enough that we'll never see that planet again. Of course, if the other guys have had the same idea, we'll need a strategy to deflect them. Pretending we're gay might seem like a good idea, but before you know it, they'll be "adopting a wide orbital stance" and stalk us forever.
Suggestions anyone?
Keep in mind that Voyager, apart from some gravitational assists, wasn't ever really made to "go fast". Even now, there are ways to send things moving much quicker such as the Ion Thruster which although not NEARLY as powerful as a chemical rocket, is amazingly more efficient. The Weight to Thrust ratio is fantastic and could well be utilized to provide constant thrust for a long time. Once you exit the earth's gravity well, something like an Ion Thruster could over a number of years accelerate a craft to a much higher speed.
Moved to http://soylentnews.org/. You are invited to join us too!
If that planet were inhabited by a technological civilization, we should have been detecting their twelve-year-old radio transmissions, faint as they might be.
Could you get more by slingshotting around the sun?
Yeah, but you'll end up in San Francisco in 1986 so it won't do you any good.
The math is wrong - Voyager I is 0.71 light days away, or 0.0019 light years away. It will take a lot longer than 840 years to get to another star.
Gravity is GM / R**2. Mass is proportional to R**3, which means that Gravity is proportional to R, if the density is the same. Inverting that, Gravity is proportional is M**(1/3), so 4 times the mass is 1.587 times the gravity (for a constant density).
So, I wouldn't rule it out.
Um, that's not quite how orbital mechanics works. Helios II started off from the earth - that is, with a lot of potential energy in the sun's gravitational field. It was put into an elliptical orbit around the sun, so on its closest approach, part of that potential energy was converted to kinetic energy (hence the high velocity), but at the most distant point, it's all converted back to potential energy, and there's zero gain. It's a bit like bouncing a rubber ball off the floor: it's surely going to hit the ground at a high velocity, but it's never going to bounce up higher than it started - no free lunch. The reason why slingshotting between planets works is because they move relative to each other. To use the rubber ball analogy again, if you throw a rubber ball at the front of a truck that is rapidly approaching you, the rubber ball will come back with a higher velocity. What you did is subtracting kinetic energy from the truck, just like a slingshotting probe subtracts kinetic energy from a moving planet. The tricks we use to make space probes gain kinetic energy are not unlike bouncing a rubber ball repeatedly between moving walls. To use the sun for slingshotting, one would require a very massive object in a highly eccentric orbit around the sun as a "second wall", which our solar system unfortunately doesn't have. (Or should that be: fortunately for our existence?) One could try to use pluto, but I doubt it's massive, eccentric and fast enough to be worth it.
Disclaimer: the above explanation is obviously somewhat oversimplified.
You're forgetting that we can see our own TV signals, sent out and then reflected back at us by an unknown source from 47 years ago. If a low quality mirror is enough to span 47 light years, than a direct view of something 12 light years away should be fine.
AGGGH just noticed the date on that article. I'm such a tool.
The listing I saw said Tau Ceti is about 5.8 billion years old and about 0.78 solar masses. Lifetime of main-sequence stars goes like 1/M^3, so Tau Ceti's lifetime is about twice as long as our sun's. It will be still be looking pretty healthy when our sun has got all bloated and ugly.
Don't feel too badly, you were on the right track. IIRC clear back in the 1970s it was determined that at TV frequencies the Earth was the brightest (known) object in the galaxy.
It's easier to be a result of the past, but more fun to be a cause of the future! http://www.spacefinancegroup.com/
Why would you put the people in charge on the second bus?
"On a small scale" is an understatement. We have virtually sent no signals at all. To any system past Alpha Centauri we would be dead silent on a radio scan of our system 99.9999999999999999999999999999% of the time. Are you wondering why we haven't made any effort to send signals? Fear. Even many radio astronomers themselves are frightened of attracting the attention of more advanced civilizations that may be listening. If we are too afraid to do it other civilizations may be as well. So we all listen but never speak. Everyone will stay very quiet out of ignorance and fear. Hence Fermi's Paradox and The Great Silence.
Quite an experience to live in fear, isn't it? That's what it is to be a slave.
it was determined that at TV frequencies the Earth was the brightest (known) object in the galaxy.
That is until they learn to decode the signals. Then they will stop thinking we are bright.
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If we want to send people for thousands of years, I think it should be an artificial uterus with some deep-frozen zygotes in it. When you arrive you crack open the eggs, and voila! Adam and Eve.
So basically it is like high school dating on a galactic scale?
Hello out there! Any potential overlords looking for a slave race that's advanced enough to be useful without being able to defend itself effectively? And might be tasty?
Il n'y a pas de Planet B.
The Vulcans came from the habitable planet that orbited Tau Ceti, according to my Starfleet Technical Manual. Given that they invented the Prime Directive, they probably have to maintain radio silence (frex, using very directional masers where necessary for radio-band communications) to avoid clueing in lesser civilizations.
Plus the Andorians live right next to them and we all know what they are like.
The Burvixese race evolved on the planet Arcturus 1, progressing from turtle-like swamp dewellers to a benevolent, highly technological society in just over fifteen million Earth years. Although the Burvixese had the wherewithal to build crude interplanetary vessels, they preferred to remain on the comfortable damp surface of their world and explore the galaxy through HyperWave communication. Using this method, the Burvixese made contact with several neighboring alien cultures, including the Utwig, the Gg, and unfortunately, the Druuge, whom the Burvixese would have been much better off never finding. For many decades, the Burvixese exchanged information with these races, trading technological, historical and philosophical facts and theories, until the fateful year 2142. It was then that the Gg announced that they had come under attack by a unknown alien race, who appeared to want nothing less than their complete annihilation. The Gg surmised that the hostile race, the Kohr-Ah, had located them using the Gg's HyperWave transmissions. Knowing that they had little chance of survival, the Gg warned the Burvixese that, unless they restricted their own transmissions, they too might face a gruesome fate.
Being a charitable race, before the Burvixese turned off their HyperWave transmitters, they shared the Gg's warning with the Druuge. But it was too late. The Druuge's powerful advertising beacons had already attracted the attention of the murderous Kohr-Ah, who, having finished with the Gg, began moving in the general direction of the Persei constellation, home of the Druuge. Realizing their peril, the Druuge took immediate action. They ceased all transmissions and sent a task force of their fastest ships to the moon of the Burvixese world. Once there, the task force assembled a huge HyperWave broadcaster on the moon's surface. When it was complete, the Druuge activated the unit which began emitting powerful HyperWave signals, focused directly toward the oncoming KohrAh fleet. The Druuge hoped that the hostile aliens would change course toward the Burvixese planet and fail to find their own worlds. Unfortunately, this ruse was all too effective: the Kohr-Ah changed course, attacked the poor Burvixese and, sadly, destroyed them all in three days of orbital bombardment.
--Star Control 2 manual
Shutting down free speech with violence isn't fighting fascism. It IS fascism!
You make me post this in every extrasolar planetary thread and it's really annoying.
Voyager 1 is nowhere near current technology. We have ion thrusters now. We have supercomputers now. Hell, your cellphone would have been a supercomputer to the guys who designed that thing. We have water on the moon, in near-earth asteroids, and a limitless supply in Ceres, and we didn't know that then. We have new methods of separating that water into hydrogen and oxygen on orbit efficiently, so it doesn't have to be hoisted out of our gravity well. We have far more understanding about long-term space missions and habitation. Plants grow in space! We didn't know that either. We have commercial rockets that can dock with the space station: an absurd sci-fi fantasy back then. We have robots who can do the work of gathering fuel without too much supervision. We have robots that could survive the kind of acceleration provided by a 1000 km railgun that it would take to put the robots there in a reasonable time, and a place in low-g to put that rail gun and robots to build it. And software to put on the robots that apparently can withstand a 24 year ping time.
In fact, recent learnings about the Voyager Anomaly point to an obvious way to propel interstellar spacecraft: Put a couple dozen 200 MW fission reactors behind some heat/radiation shields and point them in the opposite direction from where you want to go, and let them melt down. The heat provides thrust. At 745 W per HP, that's good for a few thousand horsepower of thrust. Since a Newton is a Horsepower-second, near enough, and the reactors run for many years, that's insane number of Newtons. We actually used to have a project that worked on this theory called Project Orion.
So, for example, get the robots to gather up some water and refine it into LH2/LO2. Slide some of that fuel down to LEO and pick up a commercial hydrox booster and lift it into high orbit and fill it. Repeat until you have seven of them. Now arrange them in a filled hexagon at L2 orbit just beyond the moon, and fill with hydrox. Strap your meltdown-driven spacecraft and habitat/humans/robotic exploration package on the nose, and at the most opportune time when your cislunar orbit is headed closest to the desired direction, light that shit off. Boost for 2.5 minutes at 6 g, and discard the 7 Saturn boosters. You're already several times past solar system escape velocity, and your course is assured. Then engage the thermal drive and melt down the reactors and continue to boost at something on the order of 40 billion Newtons per year as you head to the nearest star. Somebody do the math for me. I'm thinking 50 years.
"Oh, but the cost!" you might say. Well look. We don't need the work of all the people we have. It turns out that something like 1 in 4 Americans is all that's required to maintain our standard of living. According the US Bureau of Labor Statistics we have 11 million underemployed people in the US, or $500B/year worth of people who could do be doing something interesting and useful who aren't. And that's just the US, and I think that number is understated 2x. Besides, we'd like to be rid of that nuclear fuel anyway.
I'm not even in the space field and I could figure out how to get people to Tau Ceti in under one human lifespan with resources like that, or robots sooner still. We could do it, right now, with the resources and science that we have. It would be a one-way trip, but we would not lack for volunteers or robots. From one economic point of view it wouldn't cost us one whit more than we're already paying, and instead of being unhappily idle the proletariat would be excitedly engaged in a worthy endeavour. You just have to sell it.
Just because your grandparents couldn't figure out how to do this don't assume that the current generation can't.
Help stamp out iliturcy.
He had foreseen this. The planet around Tau Ceti is called Aurora. It is the home of long-living humans and mind-reading robots.
No, you do mean the inverse square law. The inverse square law states that the intensity of radio waves (or light) decreases with the square of the distance to the source. The square-cube law is about the surface relative to the volume: The surface increases with the square of the size, while the volume increases with the cube. This means that the same structure at different sizes would not have the same properties. For example, a giant ant would not be able to get enough oxygen, as its ability to get oxygen follows its surface area, while its oxygen demand follows its volume. Likewise, it would be crushed under the weight of its own exoskeleton, as its strength is proportional to the square of the size, while its weight is proportional to the cube.
I think that fear of attracting attention is very misguided. Civilisations capable of mass interstellar travel automatically have much better opportunities to pursue ... than to go torment younger single-planet civs.
Who said anything about tormenting? The Vogons did not destroy earth to torment, but for practical reasons. They were described as "Not cruel, just callous". I destroy wasp nests, but not to torment them. I recently trapped a dozen mice in my attic; I actually felt sorry for them, they look cute, but knew that if I let them be they would be taking over the house.
Such an advanced civilisation might see us as we see an ants nest. And don't depend on talking our way out of it, reasoning with them. They would be on a totally different mental wavelength. Most higher animals on Earth talk to each other (that is what "birdsong" is for example), and we have lived for thousands of years alongside them, yet most people will not even accept that they do so - let alone listen.
Isn't that exactly what the GP said?