The big question, for those scanning the skies for extra-terrestrial life, is: when will aliens make contact?
In fact, it's hard to believe they haven't already, considering the billions of stars in the universe.
According to astronomers at Cornell University in the US, they believe they have the answer, after developing a new equation that attempts to explain the Fermi Paradox.
Sadly, it's not going to be anytime soon.
The bods at Cornell, said The Telegraph, "calculated that signals from Earth would need to reach half of all the Sun systems in the Milky Way to be sure of being picked up by an advanced civilisation."
“We haven’t heard from aliens yet, as space is a big place but that doesn’t mean no one is out there,” said student Evan Solomonides who authored a paper which he will be talking about at the Astronomical Society’s meeting 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.
There are various hypotheses as to why this hasn't happened so far. Either intelligent extraterrestrial life may be rare, or perhaps - echoing practically every dystopian sci-fi film we've seen - that intelligent civilisations destroy themselves before reaching out to the stars. Or worse - we're being observed from afar as part of an experiment.
But the scientists are quite keen to explain the delay - humans have only been broadcasting TV and radio signals into space for around 80 years. "By now these signals should have reached more than 8,500 stars within 80 light years of the sun," wrote The Mirror.
Scientists referenced the “Mediocrity Principle” which that says there is nothing at all special about the Earth or its occupants, the team ruled out the likelihood of humans being among the first or last civilisations to develop radio technology.
“This is not to say that we must be reached by then or else we are, in fact, alone,” Solomonides said. “We simply claim that it is somewhat unlikely that we will not hear anything before that time.”
He added: “We are on the third planet around a tediously boring star surrounded by other completely normal stars about two-thirds of the way along one of several arms of a remarkably average spiral galaxy.
“The Mediocrity Principle is the idea that because we are not in any special location in the universe, we should not be anything special in the universe.”