A recent NASA study suggests that most extraterrestrial civilizations have died out. :

The statement comes from researchers with NASA’s Jet Propulsion Laboratory, the California Institute of Technology and Santiago High School who used an updated version of an equation to calculate the likely existence of intelligent life and determined aliens may have emerged some eight billion years after our galaxy formed.

With these results, the team included the idea that progress of science and technology inevitably leads to the destruction of civilizations and because humans have yet to make contact outside our planet, scientists now think they know why…

‘If intelligent life is likely to destroy themselves, it is not surprising that there is little or no intelligent life elsewhere.’

Stacy Liberatore, “The Milky Way may be full of dead aliens who were ‘annihilated’ by their own science and technologies, study suggests” at Daily Mail (December 23, 2020)

Matt Williams raised this possibility and many others at Universe Today: “Maybe there are just very few aliens out there…

It seems like a fatalistic approach. If there is such a law in the universe—that advanced technologies spell annihilation—why didn’t it kick in a long time ago, when people invented metal or something? Just a thought.

You may also enjoy these accounts of why we do not see the aliens:

1.Are the Aliens We Never Find Obeying Star Trek’s Prime Directive? The Directive is, don’t interfere in the evolution of alien societies, even if you have good intentions. Assuming the aliens exist, perhaps it’s just as well, on the whole, if they do want to leave us alone. They could want to “fix” us instead…

2.How can we be sure we are not just an ET’s simulation? A number of books and films are based on the idea. Should we believe it? We make a faith-based decision that logic and evidence together are reasonable guides to what is true. Logical possibility alone does not make an idea true.

3.Did the smart machines destroy the aliens who invented them? That’s the Berserker hypothesis. A smart deadly weapon could well decide to do without its inventor and, lacking moral guidance, destroy everything in sight. Extinction of a highly advanced civilization by its own lethal technology may be more likely than extinction by natural disaster. They could control nature.

4.Researchers: The aliens exist but they are sleeping… And we wake them at our peril. The Aestivation hypothesis is that immensely powerful aliens are waiting in a digitized form for the universe to cool down from the heat their computers emit.

5.Maybe there are just very few aliens out there… The Rare Earth hypothesis offers science-based reasons that life in the universe is rare. Even if life is rare in the universe, Earth may be uniquely suited to space exploration, as the Privileged Planet hypothesis suggests.

6.Does science fiction hint that we are actually doomed? That’s the implication of an influential theory as to why we never see extraterrestrials. Depending how we read the Kardashev scale, civilizations disappear somewhere between where we are now and the advanced state needed for intergalactic travel.

7.Space aliens could in fact be watching us. Using the methods we use to spot exoplanets. But if they are technologically advanced, wouldn’t they be here by now? The Hart-Tipler conjecture (they don’t exist) is, of course, very unpopular in sci-fi. But let’s confront it, if only to move on to more promising speculations.

8.Is the brief window for finding ET closing? According to some scenarios, we could be past our best-before date for contacting aliens. Of course, here we are assuming a law of nature as to how long civilizations last. Can someone state that law? How is it derived?

9. What if we don’t see aliens because they have not evolved yet? On this view, not only did we emerge during a favorable time in the universe’s history but we could end up suppressing them. The Firstborn hypothesis (we achieved intelligence before extraterrestrials) lines up with the view that humans are unique but sees that status as temporary.