Is there Life anywhere else?

Since writing the talk given last Sunday dealing with the immensity of the Universe, and anticipating the talk to be given this week on the miracle of life, I have revisited the arguments make by Frank Drake and Carl Sagan back in the 70's for the inevitability of some form of life showing up in many other places in the Universe.


In my early encounter with this question, the argument was used that the location of the Earth is so special, so unique, that the chances of other planets being found with the same set of environmental characteristics to be next to nothing.  I remember very clearly riding the bus home from school (we lived on a farm about 12 miles out of our very small town of Brashear, MO) and pondering what my fifth grade teacher had said that day.  That may have been my first experience of realizing that "grown-ups don't know everything."


But think about it -- astronomers estimate that in the visible Universe there are perhaps a trillion galaxies with an average of at least 50 billion stars in each. 


Let's put that in perspective before we get lost in the trail of all those zeros. A billion pennies would fill our sanctuary of 32'x50'x11'. A trillion pennies would fill an area of about 1 mile long by 300' wide piled 11' high. Multiply that by 50 billion -- if a penny represented each star, you'd have the volume of a cube measuring over 90,000 miles on each side, filled with pennies.  OK, so that's a lot of pennies -- and stars.


Astronomers are also finding that about ten percent of the sun-like stars have planetary systems. Of all the stars out there, about 2% are like our sun -- long lived, relatively steady energy output, relatively "hospitable" to evolving life forms. Just a mere .2% of those pennies stacked in that cube that measures 90,000 miles on a side (i.e. 9,000 miles long by 9,000 miles wide by 18,000 miles high -- in pennies) -- that's how many "life hospitable" stars would have planetary systems that could contain an earth-like planet. But that's still a LOT of planetary systems around "hospitable" stars in the universe within which Earth-like planets could exist. 


Of course, "Earth-like" is not a prerequisite for life. Just last week I read that it is entirely possible that life may presently exist on Titan, the largest of Saturn's moons. The Cassini probe is finding less hydrogen and less acetylene (yes, the torch fuel that welder's use) at low elevations of Titan than is expected based upon what we do know about Titan's atmospheric chemistry. One explanation of that deficit of hydrogen and acetylene is that there is a Titanian microbe digesting it. Hmmmm. Would we qualify that as life? Of course! http://www.sciencedaily.com/releases/2010/06/100606103125.htm


Even if such a microbe is constantly feasting on torch fuel right in our "backyard", we wouldn't expect to communicate with it for another few hundred million years. Are we the only higher life form in the universe (i.e. technologically advanced and able to communicate)? I am certain the answer is "no". Will we ever encounter those other higher life forms? Based upon what we presently know of physics and the energy it would take to move a vehicle of any size across the vast distances of space, it's unlikely. However, to assume that we fully understand the laws and limitations of physics hearkens back to the statement made in the early 1800's by one of the leading scientists of the time that "we know all we need to know about the universe. Further research is unnecessary". According to him, all we had to do was apply that knowledge! 


Will we ever encounter those alien life forms? Who knows. Maybe we already have. There seems to be mounting evidence that many of what we have called unidentified flying objects are something other than "swamp gas" or weather balloons. 


Isn't this process of discovery interesting?


Know you're blessed -- all the time.