No Moon Needed For Extraterrestrial Life 246
sciencehabit writes "Given the generally accepted idea of how Earth got its big moon — through a dramatic collision with a Mars-sized body that knocked a huge chunk of Earth loose — astronomers estimate that only 1% of all Earth-like planets in the universe might actually have such a hefty companion. That would mean planets harboring complex life might be relatively rare. But researchers have now carried out large numbers of detailed numerical simulations of 'moon-less Earths,' which show that the consequences are less dire than is generally assumed. According to the simulations, these planets would have ample time for advanced land life to evolve. As a result, the number of Earth-like extrasolar planets suitable for harboring advanced life could be 10 times higher than has been assumed until now."
Re:No Werewolves! (Score:3, Insightful)
What about tides, seismic activity? (Score:4, Insightful)
Don't tides and seismic activity play big roles in how we think life evolved?
Re:Fake forumla continues to sink (Score:3, Insightful)
It's only idiotic if you demand that it be accurate, if you use it as a framing of the discussion, it is a nice place to start.
Re:and given that assumption is now questioned... (Score:3, Insightful)
Re:Fake forumla continues to sink (Score:4, Insightful)
R* = the average rate of star formation per year in our galaxy
fp = the fraction of those stars that have planets
ne = the average number of planets that can potentially support life per star that has planets
fl = the fraction of the above that actually go on to develop life at some point
fi = the fraction of the above that actually go on to develop intelligent life
fc = the fraction of civilizations that develop a technology that releases detectable signs of their existence into space
L = the length of time for which such civilizations release detectable signals into space.[3]
So, with fl,fi,fc and L (4 of 7) being completely unknowable, the result N is something more than parlor talk? No.
I'm all for parlor talk and will ponder extraterrestrial life with anyone. My personal opinion is there is other intelligent life, it's just really friggin' far away.
Make a percentage estimate? Pfffft! It's bullshit.
Re:and given that assumption is now questioned... (Score:5, Insightful)
I don't know that I'd call it wishful thinking ... it's a framework to discuss the likelihood that another planet exists out there with an intelligent civilization.
Whether or not we're alone in the universe has been one of the "great questions" of man for centuries now ... I don't think knowing the answer to that, or working towards one it just wishful thinking.
Drake's equation is more of a starting point to have a discussion, it mostly just tries to frame the complexity of what's being discussed. It's like Moore's law -- it's value isn't so much in that it authoritatively explains anything. It certainly has very few assumptions inherently built into it -- it's an expression of what the chances are based on how much we think the values of the individual terms change. It is definitely more of a thought experiment than it is an equation, which was the whole point.
Quite frankly, I'd rather know that there's life out there, even if we can't ever reach it or communicate with it. If for nothing else, to have something to throw up in the face of the creationists who believe that god created the entire universe just for us -- not that I'd expect them to believe anything based on science.
I think now that we've started discovering hundreds of exoplanets, Drake's equation starts to get a few more terms filled in -- and the number of stars with planets has become a much greater number than previously thought. I seem to recall 15 or so years ago, the assumption was that stars with planets would be exceedingly rare and that we were a fluke. Change that one assumption alone, and you need to think about it differently.
Re:Fake forumla continues to sink (Score:3, Insightful)