Stephen Hawking, of all people, is still worried that aliens may find us before we find them.  Excerpt:

Humanity should be wary of seeking out contact with alien civilizations, Stephen Hawking has warned once again.

In 2010, the famed astrophysicist said that intelligent aliens may be rapacious marauders, roaming the cosmos in search of resources to plunder and planets to conquer and colonize. He reiterates that basic concern in “Stephen Hawking’s Favorite Places,” a new documentary streaming now on the CuriosityStream video service.

“One day, we might receive a signal from a planet like this,” Hawking says in the documentary, referring to a potentially habitable alien world known as Gliese 832c. “But we should be wary of answering back. Meeting an advanced civilization could be like Native Americans encountering Columbus. That didn’t turn out so well.”

For what it’s worth, some other astronomers believe Hawking’s caution is unwarranted. Any alien civilization advanced enough to come to Earth would surely already know of humans’ existence via the radio and TV signals that humanity has been sending out into space since 1900 or so, this line of thinking goes.

Forget the Native Americans meeting Columbus.  If we’re talking about an alien civilization capable of interstellar travel, it might be more like our modern civilization going to war against trilobites.  We may seem so hopelessly primitive as to be undeserving of any moral consideration.

Of course, we can also hope that they may be kinder, gentler aliens that will will have some kind of non-interference code – a Prime Directive, if you like.

Far more likely is this:  No aliens have detected us, any more than we have them.  Of the billions of stars in billions of galaxies over billions of years, it’s hard to credit that life only arose on this one little blue marble.  But those billions of stars are separated by billions of miles, besides by billions of years, and any detectable emissions from Earth have only been propagating for a little over a hundred years.  We just haven’t been around that long.  A hundred light years only encompasses a very, very small stellar neighborhood.

I think Dr. Hawking, brilliant as he may be, is getting himself apprehensive over nothing.