(September 27, 2012 at 11:37 pm)teaearlgreyhot Wrote: I can't comprehend the fact that each one of those galaxies might be teeming with life. That is just...wow...
It is mind-boggling...
There are hundreds of billions of galaxies in the observable universe.
On average, each galaxy contains hundreds of billions of stars.
We have been able to detect extrasolar planets orbiting main-sequence stars for 17 years - and we are finding them in abundance. We've been able to detect lower-mass (presumably terrestrial) planets for only a couple of years, and we are discovering those in relative abundance as well.
It's estimated that on average, there are at least 1.6 planets for each of the 100 billion or so stars in our galaxy alone.
Even if only a tiny fraction of those planets are suitable for the development of life, there are likely to be millions of them in our galaxy alone.
If only a tiny fraction of those have actually developed life, there could be hundreds to tens of thousands of life-bearing planets in our galaxy alone.
Multiply that hundreds to tens of thousands of life-bearing planets by a couple hundred billion and imagine the possibilities.
