This makes the whole thing boring and seemingly futile. Unless a group of us decide to waste twenty or so years traveling to a planet that could possibly not be what it seems.
It wouldn't be wasting 2o years, it could be wasting 5o, or 2oo. If the atmosphere was suitable for humans, I assure you that people would want to go, and in the time it would require us to build a stable stasis/cryogenic system, space travel will have more corporate investment, meaning the government would have less to no say on whether it's "worth" sending people there. If it's livable, I assure you Virgin would offer flight plans to the public~
The reason why this is quite exciting is because one, the estimated distance for earth-like planets (being the right distance from the sun and having a defender planet like Jupiter) are one every 100 light years (which isn't that much really). So a 2o LY distance is quite a fine compromise, no? IF the planet has water on it, we will receive a huge jump in the information of life's creation, even if there is no life what so ever.
I truly don't see reasons to send targeted signals like Holk suggested as while life may be present, the fact that we haven't received any signals (radio, irregular noise) shows that they would not be intelligent enough to make it, therefore receive it.
Two, I highly and utterly doubt that IF life is there in any form, it would be self aware-intelligent life, as I assure you we humans are an utmost freak of nature. High intelligences is not needed, at all, for nature to continue and thrive, therefore natural evolution wont automatically stray to that path.
Three, we
are sending them signals, that planet has received millions of them. Tv, radio and of course the infamous W.O.T~ SETI.
I would be surprised and empathically happy if we found a basic mildew there quite frankly =o
To clear it up ataraxy~ No we don't know if water's there, it may have evaporated in the early stages of the planets life. It's still very exciting though =)