BBC NEWS | Science & Environment | Galaxy has 'billions of Earths'My wallpapers at home and work are pieces of the Hubble Deep Field shots. More galaxies than you can count, with billions of stars in each one. And I look at them and wonder...
There could be one hundred billion Earth-like planets in our galaxy, a US conference has heard.
Dr Alan Boss of the Carnegie Institution of Science said many of these worlds could be inhabited by simple lifeforms.
He was speaking at the annual meeting of the American Association for the Advancement of Science in Chicago.
Are we alone? How could we be? How could it possibly be that the circumstances that brought intelligent life into being are so incredibly rare that only our tiny planet out of all the billions of galaxies and their individual billions of stars could produce only ONE place that fostered life and intelligence?
When I was a kid, the original Star Trek was showing. I was captivated by the idea of going between planets, seeking out new life and civilizations. I thought, when I grew up, that we'd be moving into space - the moon first, then Mars...and then human spaceflight shut down after Apollo 17.
And I have to wonder sometimes... does a civilization (assuming there are others in the cosmos) normally end up looking up and out to the stars, and then pulling back in an agoraphobic frenzy as we did? Were we scared by the possibilities? Was the challenge too much? Or did politics have much more to do with it than a fear of the limitless deeps?
Ah, well. It's all speculation. I don't expect I'll ever know the answer.
But while there's things like the Hubble, I can at least hope other life, other civilizations, were able to get over the hurdle that we stumbled and fell over... and then we quit the race.