The Drake Equation

Frank Drake is a famous astronomer. He played a leading role in the establishment of the gigantic Aricebo Radio Astronomy Observatory in Puerto Rico. 

Frank Drake has long been focused on some of the most important questions known to humankind...

In the vastness of the universe, are we the only intelligent lifeform? Does life itself only exist here on Earth?

In 1961, Drake and his colleagues took a set of assumptions, based mostly on theory, and came up with a mathematical equation as a way of estimating the number of other places in the universe that might support life. It is now called, The Drake Equation.

Here is a video link that features Drake's colleague, the late, great astronomer, Carl Sagan, explaining, The Drake Equation...
 
http://www.youtube.com/watch?v=0Ztl8CG3Sys

Given the incredible expansiveness of space, and the near infinite number of galaxies in the universe, each filled with massive numbers of stars;  etc., etc....what comes out of this very engaging, intellectual exercise depends on the assumptions put in.   The Drake equation shows just how much that must go right in order for life to exist. Having said that, it also shows that though the conditions for life might be exceedingly hard to come by, there are so many possibilities in the vastness of the universe, that life, even intelligent life, could be common.  Then again, it might not be...  

Astronomers have been trying to detect incoming radio signals from every corner of space since the early 80s..  In all that time, nothing has come up that could be attributed to alien intelligent life from some other part of the universe.  The search continues...

The takeaway is there is no place in the vicinty of planet Earth that is particularly hospitable to life...at least not for life as we know it.  We humans may be unique.  We may well be alone in the universe.  We  have only one planet on which life flourishes, and we know that all seven billion plus of us humans depend on its rapidly dwindling, living bounty for survival. The smart play would be to appreciate what we have, and take very good care of it.  Unfortunately, that's not how it's going.  We need to mend our ways, and we need to do it soon, before its too late...