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.

Comments

In effect, what they are saying, is

[Jane Q. Public]

that it will take hundreds of years to tell if they are truly Earth-like. And that is complete nonsense.

Once we find a sufficient collection of candidate planets using this instrument, we can devise a different device/experiment to narrow down whether they are Earth-like. That should take maybe a few years to ten years.

That is more-or-less the pattern we have been following, and it has been successful so far. I see no reason to change.