In 1960, the astronomer Francis Drake pointed a radio telescope located in Green Bank, West Virginia, toward two Sun-like stars 11 light years away. His hope: to pick up a signal that would prove intelligent life might be out there. Fifty years have gone by since Drake’s pioneering SETI experiment, and we’ve yet to hear from the aliens.
But thanks to a host of discoveries, the idea that life might exist beyond Earth now seems more plausible than ever. For one, we’ve learned that life can thrive in the most extreme environments here on Earth — from deep-sea methane seep and Antarctic sea ice to acidic rivers and our driest deserts.
We’ve also found that liquid water isn’t unique to our planet. Saturn’s moon Enceladus and Jupiter’s moons Ganymede and Europa harbor large oceans beneath their icy surfaces. Even Saturn’s largest moon, Titan, could spawn some kind of life in its lakes and rivers of methane-ethane.
And then there’s the discovery of exoplanets, with more than 1800 alien worlds beyond our Solar System identified so far. In fact, astronomers estimate there may be a trillion planets in our galaxy alone, one-fifth of which may be Earth-like. As Carl Sagan famously said: “The Universe is a pretty big place. If it’s just us, seems like an awful waste of space.”
Now some scientists believe the hunt for life beyond Earth may well pay off in our lifetimes. “There have been 10,000 generations of humans before us. Ours could be the first to know,” said SETI astronomer Seth Shostak.
But what happens once we do? How would we handle the discovery? And what would be its impact on society?