>But, it is fun to imagine how our belief systems would have been shaken up if scientists were able to show Oumuamua was an interstellar probe

Just about every ancient tradition has some form of non-human intelligent beings who are not god(s). Polls suggests almost 50% of Americans believe in ghosts[0]. I don't see why any belief system would change too much given what people already believe.

The only people who perhaps should worry are the aliens - surely a significant portion of humanity will find some way of blaming all our problems on them.

[0] https://www.newsweek.com/more-45-percent-americans-believe-d...

https://www.nytimes.com/2021/10/28/style/do-you-believe-in-g...

>but advanced alien civilizations capable of interstellar travel would probably look at us like we look at mold

Why? An advanced civilization wouldn't have cultural curiosity? They wouldn't want to study us from all the different perspectives we study people and literature and philosophy and even biology and neurology etc etc?

I've got a better theory. Interstellar civilizations have probably fought wars over habitable planets and in the aftermath of those wars they probably have set up some rules for a long time about what you're allowed to do on habitable planets in a galactic framework. In fact, the reason this planet is not strip-mined and every living thing on it dead thousands of years ago is they probably have some rights in there given to life that evolved on a planet.

Besides, E.Ts can probably do ok in deep space or underground on lifeless planets if they can do interstellar travel.

Earth has been around for about 4.5 billion years, about 1/3rd of the age of the universe. If another technological civilization that is more advanced than us by even 1M years is watching earth, and suddenly this planet starts spitting up rockets, satellites, nuclear explosions etc., that seems pretty interesting. That's one species out of 2+ million on earth, which is one of trillions & trillions of dead planets, that manages to transcend the atmosphere.

But to your point, I guess at the scale of even just the known universe it's hard to assert that anything is common or rare.

If we found mould on mars or anywhere without terrestrial origins it would be the subject on intense scientific curiosity

Maybe aliens are trying to contact us in a way they understand.

SETI has been sending unconventional radio signals to random spots of the cosmos and waiting for a quick response. An extraterrestrial SETI might have launched ʻOumuamua a billion years ago hoping that it would be detected by alien life.

I propose we find a cool Earth rock, launch it to the solar system Vega, and wait a couple billion years for an alien response.

> advanced alien civilizations capable of interstellar travel would probably look at us like we look at mold

Like a mycologist, you mean?

This presupposes an advanced alien civilization only sends out probes to places they find interesting. I think it is just as plausible that an advanced civilization would just shoot out a billion probes at random to zoom through the universe collecting data.

The problem with that should be obvious.

Mold does not detonate nuclear weapons, emitting gamma rays into deep space, nor does it have an RF noise bubble out to 50 light years.

An optical survey of our atmosphere would demonstrate techno-signatures. Any observers in NEO would see city lights and pick up radio stations. Radar observation would reveal aircraft.

If 'Oumuamua is a probe, it appears that it would be a fairly simple one. To a sufficiently advanced civilisation, it would probably be relatively low-cost. If an alien civilisation has a reasonable degree of curiosity, sending a cheap probe to examine another star system is likely worthwhile.

It depends on how rare life is in the universe.

What if we're the first mold they've ever discovered? It would be a historic meeting for both civilizations.

If we were an advanced alien civilization capable of interstellar travel, how would we look at a planet/species like 2023 Earth?

> But, it is fun to imagine how our belief systems would have been shaken up

I think such a revelation would have almost no impact. Let's be real, people that are all in on religion didn't get there using logic. Adding one more unanswered question isn't going to change anyone's mind.

Intelligent life is rare enough that I think they would find us at least mildly interesting.

Finding alien mold would be immensely exciting in my opinion.

Not necessarily a probe, maybe just a piece of cosmic junk? An equivalent of our rocket booster or a Tesla Roadster on its way to Mars.