BBC article: our galaxy has billions of Earths
Monday, February 16, 2009
A BBC article came out yesterday on pretty much the same subject I wrote about three days ago, that the huge numbers of stars in the galaxy and the fact that our solar system is nothing special whatsoever means that there are likely a huge amount of Earth-like planets in the galaxy, many with life. Whenever this discussion comes up on a board somewhere you're more likely than not to see someone reference the Fermi paradox to contradict this, but the Fermi paradox (the paradox that if life is so common throughout the universe then why isn't there any sign of it?) refers to civilization, not life itself. There could even be microbial life in locations as close to us as the cloudtops of Venus, but even in a location as close as this we're not able to discover it without sending a probe directly into the clouds (the Soviet Union did send two probes like this in the 80s but they only flew for a few hours, not the few months we would probably need to get any idea of whether there's any life there).
The article says:
Dr Alan Boss of the Carnegie Institution of Science said many of these worlds could be inhabited by simple lifeforms.and:
I for one am much looking forward to finding these Earth-like planets as quick as possible so that we can put the silly question of "are there other Earth-like planets in the universe?" behind us. Don't forget that even Venus would be classified as Earth-like when looking from another solar system, because our extrapolations as to the surface conditions on any one planet in another solar system right now are educated guesses at best.But, based on the limited numbers of planets found so far, Dr Boss has estimated that each Sun-like star has on average one "Earth-like" planet.
This simple calculation means there would be huge numbers capable of supporting life.
"Not only are they probably habitable but they probably are also going to be inhabited," Dr Boss told BBC News. "But I think that most likely the nearby 'Earths' are going to be inhabited with things which are perhaps more common to what Earth was like three or four billion years ago." That means bacterial lifeforms.
Dr Boss estimates that Nasa's Kepler mission, due for launch in March, should begin finding some of these Earth-like planets within the next few years.
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