We've accounted for 95 percent of all the stars in the Milky Way. The other 5 percent are big, bright stars - the kind that dominate the night sky, but are lamentably both rare and short-lived. If biology's your thing, you can forget those guys.Seth Shostak
It's easy to reckon that the oomph to hurl even a Smart Car-size spacecraft to another star at, say, 20 percent the speed of light (and land it when it arrives) is the energy contained in 50 billion gallons of gasoline. The tank's not big enough.Seth Shostak
Recent results from astronomers who study the occasional gravitational lensing of unknown worlds by intervening stars suggest that orphan planets could be at least as numerous as the stars. In other words, there could be hundreds of billions of orphan worlds shuffling through our galaxy.Seth Shostak
Ever since the Second World War, television signals (as well as FM radio and radar) have served as Homo sapiens' emissaries into deep space. High-frequency, high-power broadcasts have filled an Earth-centered bubble more than 60 light-years in radius with signals.Seth Shostak
We haven't yet found a speck of evidence for biology on another world, so we have no objective way to judge whether life is a onetime fluke or a near-inevitable phenomenon.Seth Shostak
Sure, our three-pound brains might be inadequate to understand the universe. But perhaps they're just good enough to build something that can.Seth Shostak
The bottom line is that finding orphan planets - small, faint, and located who-knows-where - is not for the faint of heart. The task is comparable to observing a match flame at the distance of Pluto. The WISE satellite, a hi-tech, space-based infrared telescope especially suited for such work, has found only a few.Seth Shostak
Five centuries ago, Copernicus upset humanity's applecart with the news that the Earth is not the center of the cosmos. It could be that, before you've paid off your house, we'll learn that the universe is not the center of the universe, either!Seth Shostak
The next time you check your moves in the mirror and reflect on how special you are, consider that somewhere in this universe or in another parallel universe, your double might be doing the same. This would be the ultimate Copernican Revolution. Not only are we not special, we could be infinitely ordinary.Seth Shostak
The limitless content of our universe might be only one instance of a large (and possibly infinite) number of other universes.Seth Shostak
