As the Mars Rover Perseverance bumps around looking for fossil bacteria and such, many students of possible ET life are becoming surprisingly cautious about what it might mean:

“We have no reason to believe that technological advancement and altruism or morality are somehow linked,” SETI researcher Andrew Siemion told Inverse. “There probably are malevolent civilizations elsewhere in the universe so that’s certainly something that we should consider as we continue to explore the universe.”

Siemion, who’s the director of the Berkeley SETI Research Center and principal of the alien-hunting Breakthrough Listen project, is invoking a tension at the heart of any project searching for alien life. Successfully finding it would change the world — but there’s also no guarantee humanity would survive the encounter.

Dan Robitzski, “Seti Research Director Warns of “Malevolent” Alien Civilizations” at Futurism

There’s no guarantee ET doesn’t know about us already, Harvard astronomer Avi Loeb, author of Extraterrestrial: The First Sign of Intelligent Life Beyond Earth, cautions:

When you’re in an unexplored wilderness, you’d better be quiet, because you never know whether there might be dangerous predators lurking. Unfortunately, Earth has not been following this cautionary principle so far: we’ve been broadcasting radio waves into space for more than a century. If there are technological civilizations within a hundred light-years that monitor their sky with radio telescopes similar to ours, then they may already know about our existence. We could hear from them in the future.

Avi Loeb, “What Should We Do if Extraterrestrials Show Up?” at Scientific American (April 15, 2021)

Loeb notes that, using realistic time scales, even if ‘Oumuamua were an alien probe (as he still argues it is*), it took 10,000 years to cross our solar system. Our technological civilization is not even that old. And other alien craft might take a million years to travel 100 light years. In that case, malevolent or otherwise, ET may as well be history or even fiction.

However, he offers a suggestion we can follow up on: While continuing to map the Moon, search the surface for crashed or discarded extraterrestrial equipment. There is no atmosphere or geological (or biological) activity there. Thus it could be a “museum of extraterrestrial equipment.” Actually, a single fragment of ET equipment would be pretty decisive but a museum would be a massive tourist attraction — space tourism with a purpose. For public awareness, it even fits in with the new NBC TV series, Debris.

There’s a controversy simmering now about how hard we should be looking. A San Francisco-based group called METI (Messaging Extraterrestrial Intelligence), headed by science commentator Douglas Vakoch, seeks contact:

“What happens if every civilization out there is doing that, we are just listening and not transmitting,” Vakoch tells Inverse. “It will be an incredibly quiet universe.”

Passant Rabie, ““The point people miss is that it’s too late to hide”” at Inverse

METI started sending signals in 2017. Others say that’s unwise:

John Gertz, amateur astronomer and former chairman of the board of the SETI Institute, authored several papers criticizing the method behind METI.

“The ethical issue is that they’re taking a great risk on behalf of all of mankind without asking mankind for any permission,” Gertz tells Inverse.

Passant Rabie, ““The point people miss is that it’s too late to hide”” at Inverse

Physicist Michio Kaku has said similar things: “There are some colleagues of mine that believe we should reach out to them. I think that’s a terrible idea. We all know what happened to Montezuma when he met Cortés in Mexico so many hundreds of years ago.”

In the end, we’ll probably keep trying. Loeb’s idea of looking for debris on the Moon may, for now, be the best and safest idea — and it would satisfy both seekers and worriers. And several nations are now planning Moon proves anyway.

• Note: Other astronomers say ‘Oumuamua was nitrogen ice from Pluto.

You may also wish to read: Why some experts hope we don’t find life on Mars. Many thinkers worry about what will happen if the extraterrestrials land. But will they feel worse if we never find ET?

and

Sci-fi Saturday: New NBC X-files clone “Debris” feels disjointed Perhaps that’s intentional, though many critics aren’t getting it yet. Viewers are asked to ponder, will disruptive alien technologies heal or destroy? Is there a broader, cosmic purpose to our existence? (David Zeiger)