Looks like exoplanets are common afterall

[JAG2955]

Or something like that:

http://www.nasa.gov/press-release/nasas ... discovered

12 candidates that could possibly support earth-like life.

[Aesop]

I'll believe that when they find one that actually does.
We don't even know whatinhell goes on upon Venus, Mars, and Jupiter, our relative next-door neighbors.

Postulations about planets and any potential for life support reveal far more about the authors' prejudices, assumptions, and preconceptions than they do about actual scientific truth.

Tales about what they do or don't do are likely about as accurate as suppositions about earth-bound cell functioning based on observations of onesuch, from the Moon, with a telescope. On a cloudy night.
Or weather predictions for a given spot in the temperate zone, 3000 years from now, on a Tuesday.

Let's remember that for anything we're looking at, a light year is "only" 5.865trillion miles away. (Or put another way, only 27,000 years away, moving at the highest speed thus far ever recorded by humans - the Apollo 10 re-entry). Our nearest galactic neighbor, Alpha Centauri, is 4.37 of them away. And everything beyond Alpha Centauri is some multiple of that distance. If we had launched an Apollo spacecraft, or a suitable nuclear powered probe, at that star system when Cain & Abel were in diapers, it would almost be 7% of the way there, now. If we had done it when Cro-magnon man began to supplant the slope-browed Neanderthals 30,000 years ago, we'd be almost 1/3rd of the way there.
And as the trail of 32,872,500 mylar food wrappers from here to that point in space wouldn't be visible in the sky on a clear night, guesses about what might live and thrive on planets 3-3,000,000 times farther away than that are even less scientific than suppositions about the brand of underpants Bigfoot wears.

So much so as to be risible if mentioned in polite company.

But it's fun to imagine.
And hope for warp drive someday.

[Termite]

Postulations about planets and any potential for life support reveal far more about the authors' prejudices, assumptions, and preconceptions than they do about actual scientific truth.

Kind of like the Drake "equation", which is nothing more than a "W.A.G."; hell, it's not even a "S.W.A.G." It's more of a probability arguement, like "how many angels can dance on a pin head".

[MarkD]

My understanding is that there are only a few criteria used to determine if a planet could support life (note, not that it HAS life, but it COULD), and they're pretty simple and measurable even at this distance:

The first thing they look for is that it's at the right distance from the star to support liquid water, and that the orbit isn't so highly elliptical that it stays in that butter zone all thru the orbit. Liquid water, we assume, being necessary for life.

They look for enough mass to maintain an atmosphere, because little green men gotta breathe.

The second item is handled pretty well by the fact that we can only detect BIG planets anyway, so if we can tell it's there it's big enough to have an atmosphere.

And yeah, we ain't going to visit any of these places any time soon.

[JAG2955]

I'd bet a decent amount of money that Mars and Venus have some kind of extremophile bacteria/fungus/simple life, maybe similar to what's near our deep undersea volcanic vents.

I am incredibly intrigued by some of Jupiter's moons as well as Titan. If fungi can contaminate diesel, it stands to reason that there may well be microbes on Titan's hydrocarbon lakes.

Granted, we're doing the scientific equivalent of looking at a giant aerial map to choose a house to buy. But we know that there's something there, which a few short years ago, would have been impossible. We're finding out that exoplanets are common, and while potentially habitable ones are rare, they are not quite a needle in a haystack.

As for propulsion, we're starting to discover what we don't know. We're finding out things on the quantum level that we couldn't figure out before. Technology tends to move in leaps and bounds. A computer scientist from the 1940s would be about as knowledgeable on computers in the 90s as most school children. A pilot from the 1920s would identify aircraft from the 1970s as UFOs.

Our rocket technology haven't changed much since Mercury. That's not saying that things like Saturn V aren't incredible feats of engineering. It's just that we don't know yet what our next big breakthrough will be or when it will be.

[JustinR]

I really hate Apple sometimes. Ok, third try, hopefully my post won't get lost yet again by Safari's &#^&!! Refresh.

To put things in perspective, humans only created powered flight just over a century ago, which is a pretty short time span in human history. As Jag said, technology is advancing in such a way that our younger selves would be lost in the future. A daily viewing of gizmag.com demonstrates how fast new materials and manufacturing techniques are being developed. NASA's Eagleworks is testing an EM drive that theorietically shouldn't work according to most scientists, but apparently does. Just this year we finally proved the existence of gravity waves, theorized by Einstein about 70 years ago. Who knows what the next 50 years will hold in terms of our understanding of physics, and propulsion. We may or may not figure out that an Alcubierre drive is possible or impossible. Either way, it's worth looking for places to potentially explore/colonize, even if we never get there.

Assuming of course, we don't anihilate ourselves first, which is a distinct possibility.

[Aesop]

My understanding is that there are only a few criteria used to determine if a planet could support life (note, not that it HAS life, but it COULD), and they're pretty simple and measurable even at this distance:

The first thing they look for is that it's at the right distance from the star to support liquid water, and that the orbit isn't so highly elliptical that it stays in that butter zone all thru the orbit. Liquid water, we assume, being necessary for life.

They look for enough mass to maintain an atmosphere, because little green men gotta breathe.

The second item is handled pretty well by the fact that we can only detect BIG planets anyway, so if we can tell it's there it's big enough to have an atmosphere.

And yeah, we ain't going to visit any of these places any time soon.

Layman understanding here, but it has to be the right size, the right distance from the right kind of star, and have the right orbit.
I'd also love to know the inherent inaccuracy of the measurements in question, i.e. the CEP/SWAG factor of their calculations/instrumentation.
As climate "science" demonstrates, we barely grasp the fundamentals of our own ecosystem, and we've been here for our entire existence.
So other than the calculable variances in the earth's orbit WRT the sun, we don't know what the fudge factor is for, say, a planet 2% farther away, or 1% less mass, or anything like, and whether that would be a global extinction event, or just make every day like living in the Sahara, Tahiti, or the Artic, or whatever.
It may be that we live on the razor edge of improbability in being the only planet that can support life as complex as what's in this biosphere, or it may turn out that we're just in the sweetest sweet spot for our own forms, but that a wide variance is tolerable for other types as yet inconceivable to us.

Which, exactly as Termite stated, gets into Xx x Yy x Zz x Aa x Bb ad infinitum levels of Drake Equation bullshittery masquerading as scientific expression.
IOW, just because you write something in iambic pentameter, it's not Shakespeare, and just because somebody plugs in 42 assumptions for variables, the pre-ordained answer doesn't = science. It's just artfully-contrived BS.

Most of this nonsense is simply fanboys for SETI a generation later grasping at new straws to justify funding their intergalactic Bigfoot-hunting hobby, and a not inconsiderable number of people with an enormous axe to grind regarding religion in general and Judeo-Christian creationism in particular.
That doesn't make them wrong or right prima facie, but it shows their motives are nowhere within six time zones of being purely the joy of scientific inquiry.

I'm all in favor of the pure exploration for its own sake, but the reality is that there's metric fucktons of hokum for every microgram of actual data in this stuff. And the Moon, Mars, and the moons of Jupiter already stretch the boundaries of our capability to colonize, and as of yet we haven't even left our own planet's moon's orbit, in person.

Somebody wants to put a colony on either one in a decade, or build any of 500 actual space station colonies from the 1970s concept illustrations of the idea, has my undivided attention. If the cosmos were reduced to the size of just the surface of the earth, we're sitting on a tropical island with one palm tree in a vast lifeless sea empty to the horizon, and we've managed to wade to a small rock on the reef about 10 yards from shore, in practical terms. We aren't much more than galactic toddlers.

People talking about the possibilities of life outside this solar system, at this primitive stage of exploration, are to me on a par with people still looking for the Loch Ness Monster. In their imaginary neighbor's imaginary bathtub.
YMMV.

[Odahi]

"Breakthrough Starshot." Basically miniature light-sail probes to the Alpha Centauri system, powered by an array of lasers. They (Steven Hawking among them) think they can hit 20% of c with the technology, and make the trip in 20-30 years. And still we're only talking the most faltering of baby steps. When the best thing you can come up with for the vast majority of matter and energy in the universe is "dark matter and dark energy" because the math doesn't work without them, your math may need checking. And your physics. And your telescopes. And to say that we have any comprehension of what's out beyond our own back yard is hubris at best. "The universe is not only stranger than we imagine, it's stranger than we can imagine." I was born at least 30 years too early, I'm afraid. I'm fascinated with all things space, and delighted to my core to work in the field. But it's a cliche to say we don't even know what we don't know, yet, and we need to know before we can build. BTW, Elon Musk says he wants to send an unmanned Dragon 2 capsule to Mars, perhaps as soon as 2018. So at least ONE person on this rock is looking in that direction, and he just happens to be a smart guy, with his own rockets.

[JAG2955]

People talking about the possibilities of life outside this solar system, at this primitive stage of exploration, are to me on a par with people still looking for the Loch Ness Monster. In their imaginary neighbor's imaginary bathtub.
YMMV.

Sorry, count me among them. We've got to start somewhere, though at this point, like I said above, we don't know what we don't know. Maybe we're finding out bits and pieces along the way. It doesn't mean that we need to focus on the mountain tops in the distance, and ignore the other islands in the archipelago. We also shouldn't discount looking at the horizon if we're just trying to get to that next tiny island.

Space exploration is going to be a multi-faceted approach. We're limited by human endurance right now. But we can abuse the hell out of telescopes and probes all we want, at least until they unionize.

[Kommander]

One of the big issues as I understand it is the fact that were not sure when to start. Lets say we spend a ton of money on a few probes that will take 30 to 100 years to get to their destination. The fear is that in the intervening time we will develop an even faster way of travel that will have new probes blowing right on by the old ones, making them a waste of money. This gets even worse when were talking about manned space flight. Who wants to go into cryo-sleep for decades or die on a generation ship only to discover upon reaching their destination it's been colonized for decades or centuries via more advanced propulsion.