This recent New York Times piece, A Universe Full of Planets, is astonishing. We’ve always speculated about life elsewhere in the universe, but it just wasn’t possible to see any planets out there. And even if there are planets around other stars, what are the odds any of them would have the fortunate qualities that sparked life on our home planet?
Well, now we can see that there are plenty of planets outside of our little solar system. Even more, we can identify that a significant number are quite similar to Earth:
No matter how conservative or optimistic we are, the statistics tell us that something like an astonishing one out of every seven stars must harbor a planet similar in size to the Earth, and at roughly the right orbital distance to allow for the possibility of a temperate surface environment. In other words, roughly 15 percent of all suns could, in principle, be hosting a place suitable for life as we know it.
Since our galaxy contains at least 200 billion stars, this implies a vast arena for the universe’s ubiquitous carbon chemistry to play in — a process that, as here on Earth, might lead to the complex machinery of life. Indeed, there is a 95-percent confidence — give or take a few percent — that one of these worlds could be within a mere 16 light years of us. That’s a stone’s throw, practically our galactic backyard.
Fifteen percent of stars might have Earth-like planets? Wow! Imagine that our technology and science advance enough in the next few decades to see even more clearly the planets that might be closest to us. To discover that we are not alone, even if the cosmic distances remain too prohibitive to ever make direct contact, would have a profound effect on our species.
It would be humbling and cause quite a shift in our self perception. And it would be as exciting and as inspiring as anything that’s ever happened on this little planet of ours.