Finding Twin Earths Is Harder Than We Thought 161
Matt_dk writes "Does a twin Earth exist somewhere in our galaxy? Astronomers are getting closer and closer to finding an Earth-sized planet in an Earth-like orbit. NASA's Kepler spacecraft just launched to find such worlds. Once the search succeeds, the next questions driving research will be: Is that planet habitable? Does it have an Earth-like atmosphere? Answering those questions will not be easy. 'We'll have to be really lucky to decipher an Earth-like planet's atmosphere during a transit event so that we can tell it is Earth-like,' said Kaltenegger. 'We will need to add up many transits to do so — hundreds of them, even for stars as close as 20 light-years away.'" The abstract of their paper offers a link to the complete paper as a 17-page PDF; here is a short description from 2007 of the same researchers' work, outlining the type of spectral signature that an Earth-like atmosphere would be expected to show.
Clarification (Score:3, Insightful)
NASA needs to latch onto this. (Score:3, Insightful)
Finding a "twin" earth, no matter the distance (assuming if we can see it, we can get to it at some point in the future) is possible _the_ most important thing for the continuation of the human race.
As for being harder than "we" thought, to me at least (IANAA) it seems pretty damn hard to me. Even if we find a planet that could have human life, would it have life on it? Would that life be toxic to us? etc...
Time difference (Score:4, Insightful)
Of course, it will only be possible to tell if it was Earth-like X number of years ago. Since there are only a few stars within 100 light years, X will usually be more than 100. In the meantime, there could have been a planet killing asteroid, or an advanced civilization could have nuked itself. So, we can only really find "twin Earths" from the past. We'll never actually know what it's like until we go there...
...actually, even that's not true, in the sense that "we" means everybody on Earth. Only the travelers will know it's true. Earthlings will have to wait for the return trip or signal, to tell them that it *was* true. Even then, for most stars it would be your great-great-great.... children receiving the signal.
Bottom line? The Universe's speed limit sucks. Where's the fuzzbuster?
Re:In effect, what they are saying, is (Score:5, Insightful)
"...and it has been successful so far. I see no reason to change."
Has it? Can we really be sure that the current method is accurate in ruling out earth-like and non-earth-like?
I'm not really disagreeing with you, just not so sure that it's 100% accurate (which is ideal, but not exactly realistic). To me this sounds like they are intentionally thwarting the idea, so the public will go "well shit, guess we're trapped here for 300 more years" kinda thing.
Current method seems fine, applied to the new equipment. Keep searching, monitor the ones we already assume are earth-like, and when we figure out a way to do something about it (wormholes, etc) we pick the best candidate at that time, and go for it, if that fails, or if it takes longer than the time to build/induce/etc the next method of travel/communication, we head for the second candidate, etc... this "new" method seem to suppose that we won't be able to do anything about it for 200 more years, so we have the time to piss around with hundreds of tests, when we should probably assume it'l be possible next year, kinda like "Year of Linux on the Desktop", may never happen, but why can't it happen next year? Just because you may not succeed, doesn't mean you should't try.
Re:NASA needs to latch onto this. (Score:4, Insightful)
We don't have the technology for any type of hibernation space travel now, which is why I think its so important to follow these types of research. Even if it takes 100000 years to travel to a new planet, that's pittance compared to what it took for current level sentient life to develop on Earth.
We'll find one eventually (Score:3, Insightful)
Re:Time difference (Score:1, Insightful)
People repeating this nonsense is getting old. Yes, the fact that it's 200 lightyears away means we're seeing the planet as it was 200 years ago. But come on, use your fucking brain. 200 years on a geological scale is NOTHING. So yes, knowing what the planet was "like" 200 years ago will still give us a very relevant picture of what the planet is today.
And more generally, unless we're talking about objects outside our galaxy, the travel time of light can be safely ignored for most purposes.
Re:In effect, what they are saying, is (Score:3, Insightful)
I don't know if this is valid but, what about 10 devices doing the same job?
Life... (Score:3, Insightful)
Twin Earths? (Score:3, Insightful)
Speaking of intelligence inhabitants, it would be wonderful if we could detect such, but very unlikely, unless those inhabitants also happens to be at a technological development similar to ours, where they are leaking radio signals all over the place. Good candidates for SETI to focus its search. Maybe even the SETI@HOME crowd can put actuators on that satellite dishes to focus on said planet...
The real killer here is that even if we did find a so-called "twin Earth", we wouldn't be able to do a whole lot about it. Sending a probe there would take thousands of years. Maybe we could do a massive interferometer in space to study the planet in more detail. Forget the manned mission fantasy so many have. We have yet to put a man out past the orbit of the Moon and we're going to travel to a distant star many light-years from Earth?
The physics of Interstellar Travel is daunting, to put it mildly. When I was a kid diddling around with the Special Relativity equations, I was all elated until I realized the ENERGY required to make time dilation a useful thing -- for the travelers, anyway -- is way beyond anything we humans are likely to be able to do now and in the future -- if ever. And all those dreams I had as a young boy of going to the stars died.
Later, I got into the whole Wormhole stuff, and read some of the stuff Kip Throne and others wrote, and got depressed again. Wormholes -- if they even exist -- is far more daunting in terms of energy requirement than even lightspeed travel, by many, many orders of magnitude!!!!!!
Well, wonderful if we can find. But then we'll be more frustrated when we all have to face the realities of physics. Science Fiction lost a lot of its appeal for me because most of it turned out to be simple fantasy, impossible to achieve. My ignorance as a kid is gone.
Meanwhile, we have made tremendous strides in Science and Technology since my teen years, the stuff of Science Fiction 30 years ago. We do live in a marvelous age. It's just that Interstellar Travel will not be a part of it. :-(
Re:In effect, what they are saying, is (Score:5, Insightful)
Science is being limited much more by funding and physical constraints. Current ground based telescopes are operating very near the quantum limit and space based observatories are expensive to the point of making them infeasible.
All in all I think that pointing a few telescopes at a given object for long periods of time for a total cost far exceeding that of building a better solution is the path that is being (and will continue to be) pushed on the scientific community. The prices tags for what we want to know are so large and budgets tend to be sabotaged by political agendas as to make it appear that we are incapable of doing science for a reasonable price.
Re:Best case consequences (Score:1, Insightful)