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Finding Twin Earths Is Harder Than We Thought
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.
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?
For all intensive purposes, "whom" is no longer a word. That begs the question, "who cares"?
"...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.
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.
According to theories of what the earth's atmosphere was like before life flourished, the atmosphere was full of CO2 and nitrogen. There was no oxygen. According to our understanding of the earth 4 billion yrs ago, the earth would be a VERY different place today if there were no life here because oxygen is a byproduct of photosynthetic life. I theorize that the moment we find a planet like ours, we will have found life on another planet.
IAAP (I am an astro-physicist) and while I would love to agree with you, I cannot. The problem is not that we do not know how to get a quick measurement the problem is that is would take huge sums of money as well as very significant technological improvements.
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.