I was watching my little sister get her hair done when one of the ladies who owns the salon (go girls!) said it.
My friend, who I'll call Lola, was mid conversation with my sister when Eliza -- the other stylist -- laughed and noted 'Lola's going to say the aliens won't let us mess things up on earth too badly', or something to that effect.
My kneejerk response was to say, 'Wait, what aliens?' Thankfully, no one heard that.
But I did immediately think about the notion that the American public increasingly believes aliens are hanging out on earth. That's 34% of people in the USA these days, so about 1 in 3? Anyway, I find this notion a tad disturbing because we've messed things up so seriously already, and the wheels could totally fly off the bus in 2025. We really have to save ourselves.
I thought about how likely it would be that someone would travel 25 trillion miles to hang out around the earth playing guardian angel when there had to be big problems for the beings orbiting Proxima Centuri to solve at home, right?
So I said, 'Do you know how hard it would be to even see us in this backwater?'
Knock-knock. Who's there?
The asteroid belt, the Kuiper belt, and the Oort cloud walk into a bar. What do the interstellar aliens see? Nothing.
The problem is, most people get a simplified astronomical map all through school. This doesn't let up after grade school astronomy lessons either. They think it looks like this:

And they keep that image of marbles circling a lemon slice in their heads. They don't tend to understand that all these objects are moving at 514 000 miles per hour through space either. It's taught as if all these planets sit on a nice, stable record player.
But the science says we don't look that way at all... from the outside.
I don't do Astrophysics, but your girl likes space
Back in the 2010s at least, there were only about 6000 astrophysicists in the world. I doubt there are amore than 10,000 today. It takes PhD level chops in math, physics, and astronomy to do the job. I just happen to like space. So I decided I'd just do my best.
The problem of these better angels is that they'd be hard pressed to even see us. The picture is actually a bit more like this:

The interior planets have an asteroid belt right behind them (dust, debris, asteroids, and Ceres, a dwarf planet that makes up a third of the asteroid belt's total mass). The outer planets, including giant roomba, Jupiter, run the next span of the solar system, ending with Neptune, which is where we first meet the Kuiper belt.
If you consider the sun the yolk, you can imagine the Kuiper Belt the sizzling, crackly edges, browned in the pan. It's doughnut shaped and where a collection of dwarf planets, comets, and other Kuiper Belt Objects reign.
But that's not the end of the obfuscation. All of this sits inside the Oort cloud -- a mass of what we think are comets and really frozen objects (the old stuff in the deep freeze) that's roughly in the shape of a massive sphere.
It's long odds out there
So, if Lola's intergalactic friends are zipping around looking for lives to save, they'd have to see through the Oort cloud balloon that surrounds us, the doughnut-shaped Kuiper belt, and the asteroid belt before they spot that our blue planet is there. Long odds.
Lola reminded me our radio signals would solve the problem of our total obscurity.
But the problem is radio broadcasts started in the 20th century. It's been 100 years. I think radio waves travel at just about the speed of light in space so not a bad thought. But... have these radio waves reached as far as interstellar space?
For example, most probes haven't even passed the heliopause -- that point in space where the solar wind stops blowing because it's so far out, and beyond which the biggest influence isn't our sun anymore, but the galaxy. Only two earth spacecraft are in interstellar space, Voyagers 1 and 2. Up on the second poster, above, that heliopause would be in the darkness somewhere between the Kuiper belt and the Oort cloud.

Heck, New Horizons spacecraft only just did a flyby of Ultima Thule on January 1, 2019 (which explains what I did with my New Years party that year). Ultima Thule (or Arrokoth -- not making it up) is in the Kuiper Belt about 4 billion miles from the sun. So... spacecraft haven't reached the Oort cloud yet. And I hope there's still a NASA in 300 years when we finally do reach the Oort cloud's inner edge.
Even with the speeds at which a radio wave travels, all signals attenuate or dim to become part of the background noise eventually.
With all that, would interstellar aliens hear us?
Does public faith in aliens make aliens harder to spot
The widespread belief in alien visitation among the general public can influence the perception of scientific evidence by experts. The scientific community is a skeptical lot that may prefer that an object at rest, stay at rest, even when behaviours recorded of certain interstellar visitors (I'm talking about Oumuamua here) are so downright odd as to ring the bell on extraterrestrial technologies.
However, the scientific community is supposed to rely on rigorous methods and peer review to evaluate claims. While public opinion can shape the discourse, scientists are trained to critically assess evidence and rule out or rule in multiple hypotheses based upon it. They're not supposed to roll their eyes and assume aliens are popular baloney, totally unworthy of scientific consideration.
Yet we've seen the rout of scientific rigour to popular convention before. After all, Copernicus was spurned, and Galileo was forced to recant his theories and live out his life under house arrest. About 150 years later (half the time to the Oort cloud rn), Isaac Newton's rehashed proposal of heliocentrism (putting the sun at the center of the galaxy) was finally accepted.

So it's not ridiculous to wonder if alien life is out there. Or if it has come here. Long odds are still odds. Oumuamua ('the scout') the first known interstellar object to pass through our solar system, made its close approach to the sun, Sept 9, 2017, and spontaneously changed direction without any signs of outgassing or reduction in size (breaking up) that might force a directional change on a natural object.
The roughly flat, football field-sized thing didn't tumble madly like an icy comet shooting out superheated vapour that pushed it randomly to and fro, it accelerated smoothly to about 196 000 miles an hour and exited the galaxy again.
And wouldn't it be nice if Lola was right?
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