Apparently twenty-something*.
http://www.theatlantic.com/technology/archive/2013/11/there-are-probably-billions-of-earth-like-planets-in-the-universe/281138/
"...surveyed 42,000 sun-like stars, searching for the tell-tale visual sign of a planet: the periodic dimming that occurs when that planet crosses in front of its host star. The trio discovered, from that analysis, 603 planets, 10 of which are Earth-sized and orbit their host stars in the habitable zone (the range of distance from a host star that allows the surface temperature of a planet to be suitable for liquid water)."
I think I have an issue with both the sample size and the methodology/presumptions. But it makes for great media hype!
article abstract here (http://www.pnas.org/content/early/2013/10/31/1319909110) (apparently to read the full article you gotta pay $ :( )
*22 percent, plus or minus 8 percent. Potayto, potahto...
Direct me to the one with the green alien babes plz :)
Quote from: Mr. Analog on November 04, 2013, 03:43:03 PM
Direct me to the one with the green alien babes plz :)
meh, my guess for future events, when it comes to earthlings being involved: violent or even accidental [cultural] conquest (http://www.youtube.com/watch?feature=player_detailpage&v=REOjxvQPQNQ#t=22) is far more likely than tourism for Eccentrica Gallumbits and her ilk.
Well, I guess we better learn how to speak Klingonee