Will humans ever make contact with aliens?
With a new “UFO sighting” video going viral on social media every other week, the debate over whether we are alone in the universe continues. But a new study has dashed the hopes of anyone who hopes to meet aliens in their lifetime.
Scientists have claimed that, if we ever do find a signal from an advanced alien civilization, those aliens are likely to be dead by the time we hear it.
The study, which comes to a rather depressing conclusion, examined how long civilizations might live for and how far away from Earth they are likely to be.
It is thought there could be between 20 and 40 billion Earth-sized worlds in the Milky Way with habitable conditions. Yet we do not know how many have spawned life.
What makes discovering these civilizations difficult is their short lifespan. Astronomer Frank Drake estimated in 1961 that the lifetime of Earth-like civilizations ranges from 106 to 12,100 years or more. Considering humans have only covered 0.001 per cent of the Milky Way with signals in 80 years, it is unlikely that a civilization under 100,000 years old will still exist by the time we receive a signal from them.
Study leader Claudio Grimaldi, of the Federal Polytechnical School of Lausanne in Switzerland, concludes:
If the civilization emitted from the other side of the galaxy, when the signal arrives here, the civilization will already be gone.
The study notes that when a civilization stops emitting signals, their signals will likely continue traveling out in an echo. While it might be possible to spot these, the odds of finding a living civilization are slim.
The transmissions arriving at Earth may come from distant civilizations long extinct, while civilizations still alive are sending signals yet to arrive.
But there are potentially habitable planets within 80 light-years of Earth, which is close enough to have received a signal from us, so hope is not completely lost.