If you’ve ever studied astronomy, you’ve probably been exposed to what’s called the Drake Equation.

One side of the equation is the number of civilizations in our galaxy with which it would be possible to communicate. The other side gives all the variables that add up to that number, including the average star formation rate, the number of planets around those stars that have developed intelligent life, and the ability to send out radio signals. .

“Depending on how you calculate it, the answer may be none, or it may be a billion,” said theoretical cosmologist Katie Mack, author of the recent book “The End of Everything (Astrophysically Speaking)”.

Astrophysicist Frank Drake, who formulated the equation in 1961, said it was really a way to show “all the things you need to know to predict how hard it will be to detect alien life.”

Mack said it more directly: “The point of the equation is really to show how little we know. “

While it is difficult for professional scientists to calculate the numbers, it is even more difficult for us mere mortals to do the job.

This is where the imagination comes in. So, for generations, we’ve been putting our creative minds to work guessing if aliens exist, what they might look like, and how we’re going to greet them and themselves, than what or with a peace sign. or a ray gun.

UFO: Have we been visited?

“It’s a curious thing that for as long as we’ve imagined aliens, they pretty much look like us,” observed Chris Impey, professor of astronomy at the University of Arizona.

“A few centuries ago, they came in galleons in the sky. When zeppelins were invented, aliens flew in airships. After WWII they came in flying saucers, the latest and greatest technology we can imagine. “

Anthropomorphism – putting things that aren’t human into human form – is a constant. The same is true of the belief in alien life forms to begin with.

Strong beliefs in extraterrestrial visits

According to a 2018 Chapman University study, 41.4% of Americans believe aliens have visited Earth at one time or another, and 35.1% believe they have in recent times.

There are understandable reasons for such beliefs, Impey noted.

For decades, some people have been convinced that the US government has been hiding secrets about visitors from afar since 1947, when they believe that an alien spacecraft supposedly crashed near Roswell, New Mexico.

“When you know people aren’t telling you everything they know, you start filling in the blanks yourself,” Impey said. “Videos, stories of Air Force and Navy pilots seeing a mysterious spacecraft, it all adds up. It’s just that people are connecting the dots too quickly.

Scientists and many civilians adhere to the maxim that extraordinary claims require extraordinary evidence.

As a recent CNN story revealed, for years government and military officials ignored UFO sightings reported by military and civilian pilots – just the kind of extraordinary evidence that might corroborate the reality of the aliens. The Pentagon, which qualifies UFOs as unidentified aerial phenomena, has confirmed the authenticity of the videos and photographs accompanying these reports.

Before any recent and still-ongoing news emerged, however, a hard-to-penetrate cone of silence surrounded the entire UFO issue, at least as far as the US government and military were concerned.

Fiction fills in the gaps

Popular culture has filled in the blanks, voicing UFOs and their otherworldly passengers in vehicles such as ComicCon, films such as “Independence Day” and “ET the Extra-Terrestrial” and the classic “Star Trek” television series. “with his daring search for new life and new civilizations.

Beyond that, there is a plethora of conspiracy theories – some benign, others full of hunch – with grim warnings of kidnappings and unwanted experiments.

Impey called the UFO issue a “cultural phenomenon, not a scientific one.”

Still, he cited the call of the late astronomer Carl Sagan for all parties to the discussion to keep an open mind – “but not so open,” as Sagan put it, that “your brain drops”.

Seeking the heavens

“From time immemorial humans have wondered if we are alone,” said Stephen Strom, former associate director of the National Optical Astronomical Observatory.

It is not because the popular imagination deviates from the scientific imagination that it invalidates our hope of encountering life forms from other worlds.

After all, the question is not only whether we are alone, but also whether other civilizations have done a better job of taking care of their planets than we have done to take care of Earth. .

So it’s a question of “whether it is possible for putative complex civilizations to avoid self-destruction,” as Strom said, and whether we can learn from them before it is too late. These are among the most pressing questions we can ask ourselves today.

Certainly, most space scientists do not share the view that alien life will arrive on Earth via spaceships in humanoid form. One of them, the late cosmologist Stephen Hawking, feared that if the aliens arrived this way, they would likely be on a mission to destroy us.

That’s not to say space scientists aren’t serious about finding alien life.

“Do we think aliens are there? Mack asked. “We don’t know where, but there almost certainly is.

“It is very unlikely that life evolved in one place in the entire cosmos – the kinds of physical processes that must have happened on early Earth are probably things that have happened countless other times over. distant worlds. “

We are likely to discover other life forms through rovers, spectrometers and chemical analyzes of distant atmospheres, she added. When we do, the news will spread quickly.

As Mack said, “People really want to know.”