The Galaxy May Have Billions of Habitable Planets

The Bad Astronomer writes "A recent astronomical report (abstract in Science) came out stating that as many as 1 in 4 sun-like stars have roughly earth-mass planets. But are they habitable? A simple bit of math based on some decent assumptions shows that there may be billions of potentially habitable worlds in the galaxy. '... astronomers studied 166 stars within 80 light years of Earth, and did a survey of the planets they found orbiting them. What they found is that about 1.5% of the stars have Jupiter-mass planets, 6% have Neptune-mass ones, and about 12% have planets from 3 – 10 times the Earth’s mass. This sample isn’t complete, and they cannot detect planets smaller than 3 times the Earth’s mass. But using some statistics, they can estimate from the trend that as many as 25% of sun-like stars have earth-mass planets orbiting them!' Getting to them, of course, is another problem altogether..."

Charles Stross has a great article on this.

[Peter Trepan]

The High Frontier, Redux [antipope.org] - Covers the true scale of the distance between planets, and the energy requirements of going between them. He estimates that sending an Apollo-sized capsule to the nearest star would take as much energy as is produced on Earth in a year.

Re:Fermi's paradox.

[MyLongNickName]

I wonder what happens if we continue to expand our knowledge about exoplanets at the current rate but we don't discover life on another planet by the year 2100. Fermi's Paradox bugs the hell out of me. I can't see how we are unique... but I also can't see why the evidence of other civilizations wouldn't be obvious.

Re:NASA

[Darkness404]

Private spaceflight is a lot more promising than NASA is. Especially if the goal is to find new habitable planets. With private spaceflight, every dollar is a dollar towards a goal. With NASA its a nickel towards a goal and 95 cents spent on pointless bureaucracies.

Cut funding to NASA, allow private space companies to use the R&D, blueprints and the like and watch us achieve heights that NASA never dreamed of.

Re:Charles Stross has a great article on this.

[MightyMartian]

The distances are astronomical (ha ha). There's no economic gain at this point to going to the stars. Heck, we've barely stepped off our own rock.

Still, one would like to think that right now we're beginning the surveying aspects of future interstellar exploration, and as soon as the physicists deliver us bountiful amounts of cheap energy and some useful way around the speed of light, we will be better able to pick the targets.

Re:Fermi's paradox.

[dcherryholmes]

Perhaps true, but it is not a satisfying answer to Fermi's paradox. Tippler and others have made good arguments for colonization/exploration by robotic probes, which we also have no evidence of. Maybe it's evidence that strong AI is exceedingly difficult?

Re:Why do we assume we're unique?

[Monkeedude1212]

It's also recently been suggested by a study saying that about 1-4% of our DNA is Homo neanderthalensis - so even had THEY been the dominant species it's likely that 1-4% of their DNA today would be Homo Sapien.

Either way you slice it, any of the intelligent species on Earth appear to have a common ancestor. So whether we killed off other intelligent forms of life and thats why there aren't any is moot: none of the other animal kingdoms have shown anything along the scale that humans have, or else we'd be competing with them like we did with Neanderthals. Or there'd be intelligent oceanic life, or something along those lines.

Re:NASA

[dachshund]

With NASA its a nickel towards a goal and 95 cents spent on pointless bureaucracies.

Sometimes bureaucracies really are pointless. Other times they're the only way you can manage something as vast and multi-generational as interplanetary/interstellar spaceflight. I fear that the pro-privatization Slashdot crowd will learn this to their chagrin in a decade or two.

Right now there are functioning NASA probes at the edge of our solar system that are nearly as old as I am (a gracefully aging 34, thank you). Many of the original team members have probably left the organization, and yet scientific teams at NASA continue to diagnose problems and keep the things online. I'd love to see private space enterprise operate an unprofitable space probe for 33 years. Hell, I'd be shocked if a for-profit organization kept a legacy space probe operating for 10 years, absent massive government subsidies.

Generational Ships

[Sloppy]

With cryo-stasis ships, at least there's a reason to eventually settle somewhere. You want to wake up (or stop taking watches) and eventually start your new life. You can bear the hardships of the journey, because you have a personal goal that you intend to some day fulfill.

The thing about generational ships, is that if they're really self-sufficient and comfortable enough that the early generations don't go mad, then what's the point of landing anywhere? You can say that humans need to expand, but the people onboard won't be able to meet that need, and they're just going to have to cope with such a limited existence. But if they succeed, then that culture will be passed down, so you'll have a whole population that is happy staying in their little box. How can you plan so far into the future and keep the plan intact?

There's a Star Trek episode ("The World is Hollow And I Have Touched the Sky") where the people don't even know they're on such a ship, and the more I think of it, the more realistic and believable that seems. People wouldn't ever be able to stick to such a long-term mission in which they don't personally have any stake, so they might as well not be depended upon to achieve it, or even know it's happening. One single centralized authority with infinite patience (a computer) and a secret and tyrannical agenda, is about the only thing that could keep it going.

Re:Generational Ships

[flnca]

I thought about his pretty often, and I think that the most reasonable form of generation spacecraft would be AI controlled, self-repairing, self-sustaining, and very huge, so that Earth-like landscapes could be built in them. A ship that is 1000 km wide and high, and 10,000 km long would not be much different from a planet to its inhabitants. Clarke's 1x4x9 ratio also would make a reasonable form factor. Such a ship can of course only be built when resources are mined from the solar system planets, especially the gas giants have plenty of matter to utilize. With an "army" of robots, such a thing would be comparably easy to build and to maintain. The ship would have to have automated mining facilities, factories and so on. To the people, it would be like an ordinary world. Many of them would not need to know they're on a spacecraft. But some staff should definitely exist (an order perhaps?) that knows about the journey. Also, the government of the ship could be such that it's clear to everyone they're on a spacecraft, but then provisions need to be in place to avoid mutinies, etc.

Re:Generational Ships

[Sigmon]

Ya know... It's funny. As I was reading your post I began to imagine that similar thoughts must have gone through God's mind before he created the 'Heavens and the Earth' - assuming he did.

Just listen to the discussion here... Some of us humans have so little faith in ourselves that we're talking about creating all-powerful computer systems to control people and societies - all toward our ultimate goal. God, of course, also has an ultimate goal I think... he didn't just create the self-sustaining generational ship to get us there (Earth) but he gave us free will. He is braver and has more faith in his creation than we are in ourselves methinks.

Isn't that an interesting parallel? I can imagine God reading /. right now and saying to himself: "Yep... It's not as easy as it looks is it?... to create a self-sustaining world, put people on it and expect things to turn out how you'd like in the end."