Intelligent Alien Life Almost Certainly Existed Somewhere Else, Study Says

What would happen if we did receive a signal from aliens? DALE O'DELL/ALAMY

A long time ago, on a planet far, far away, intelligent life almost certainly existed, new research suggests.

In a study published late April in the journal Astrobiology, researchers Adam Frank and Woodruff Sullivan revised the famous Drake equation, formulated by scientist Frank Drake in 1961. This equation sought to answer the question: Does intelligent life currently exist in the universe?

But Frank and Sullivan decided to attack the problem by asking a different question: Has intelligent life ever existed on a distant planet?

In so doing, they came up with a new equation. It uses new data collected by NASA's Kepler spacecraft and instruments that show that "roughly one-fifth of stars have planets in 'habitable zones,' where temperatures could support life as we know it," said Frank in a statement. That was a big unknown at the time that Drake created his calculation.

The new equation estimates a one in 10 billion trillion chance that humans are the only intelligent species to have ever existed.

"One in 10 billion trillion is incredibly small," Frank said. "To me, this implies that other intelligent, technology-producing species very likely have evolved before us."

Frank further explained that "before our result you'd be considered a pessimist if you imagined the probability of evolving a civilization on a habitable planet was, say, one in a trillion. But even that guess, one chance in a trillion, implies that what has happened here on Earth with humanity has in fact happened about 10 billion other times over cosmic history."

In related news, a study published May 2 in the journal Nature Geoscience has identified three Earth-sized planets orbiting a star that is (only) 40 light-years away. The authors suggest these planets could be home to conditions favorable for the development of life.