I think we're alone now.
It may be time for alien-enthusiastic scientists to call a spade a spade.
So says SUNY Stony Brook astrophysicist Paul Sutter, who in a new column for Space.com insists that the search for intelligent life among the stars has run its course — though, he argues, that doesn't mean we're alone in the universe either.
"Humans have scanned and searched the heavens for signs of other advanced civilizations in the universe," Sutter wrote. "And we've found nothing. Absolutely nothing. So maybe we shouldn't be so focused on intelligent life, but on any sort of life whatsoever."
Ready SETI Go
The main idea behind the search for extraterrestrial intelligence (SETI), Sutter agued, is based on the theory that "intelligent life should be easier to detect than regular, non-intelligent life, because intelligent creatures are capable of really making their presence known."
"But something in this argument is going wrong," Sutter said. "Either intelligent life isn't as common as we might have hoped, or it's not as detectable as we might have hoped. Either way, it doesn't look like SETI will bear fruit anytime soon."
The only thing left to do, he said, is to make the search for signs of life in the sky broader, by taking into account biosignatures that could suggest less advanced life on distant worlds.
"Our first evidence for life outside Earth will take the form of a wiggle in a line on a plot, telling us that living creatures have dramatically altered the equilibrium of their home planet," he said. "Non-intelligent life may not be as common as intelligent life (though, truth be told, we have no idea how common either is), but simple creatures are still capable of making themselves noticeable."
And after all: an alien's an alien, no matter how small.
More on Paul Sutter: Researcher: Passing Star Could Yeet Earth Out of Solar System