Alien Contact Unlikely for Another 1,500 Years: Study

The Fermi paradox has puzzled scientists and philosophers since it was first posited more than 50 years ago by Italian physicist Enrico Fermi, who essentially asked: "Where are all the aliens?"

Fermi argued that taking into consideration the age of the universe and the high probability of other planets capable of developing intelligent life existing, Earth should have been visited by extraterrestrials long ago and many times over.

Taking this paradox as the basis for their own calculations, astronomers at Cornell University have now estimated that humans will most likely be contacted by aliens 1,500 years from now.

According to the astronomers, signals from Earth would need to reach half of all the solar systems in the Milky Way in order to be picked up by an intelligent lifeform. Given that signals from TV and radio were first sent into space as a byproduct of broadcasting 80 years ago, it will take around 1,500 more years for aliens to receive, decode and respond to the signals.

"We haven't heard from aliens yet, as space is a big place—but that doesn't mean no one is out there," said Evan Solomonides, a co-author of the paper who will present it at the American Astronomical Society's meeting on June 16 in San Diego.

"It's possible to hear any time at all, but it becomes likely we will have heard around 1,500 years from now. Until then, it is possible that we appear to be alone—even if we are not. But if we stop listening or looking, we may miss the signals. So we should keep looking."

Earlier this year, the hunt for extraterrestrial life was given a boost by Breakthrough Starshot—a $100 million venture headed by Russian billionaire Yuri Milner and supported by Stephen Hawking.

Breakthrough Starshot announced that it plans to send spacecraft the size of postage stamps toward Alpha Centauri, our closest neighboring star system.

Travelling at 20 percent of the speed of light, the nanocraft are expected to take around 20 years to make the 25 trillion-mile journey. Onboard cameras, photon thrusters and communication equipment will allow the tiny spacecraft to report back their findings.