Our moon is only the largest moon to planet ratio in our solar system if you discount Pluto as a planet.
Fun fact: if Luna was only about 30% heavier than it is currently, the Earth’s barycenter would lie outside of Earth, which would potentially make Earth not count as a planet by the modern IAU definition.
Sometimes I wonder if the moons size / existence is one of the reasons why life is even possible in the first place - Maybe aliens would know what it’s like to have a moon a quarter the diameter of the home planet because otherwise life has no chance, maybe life is even more likely on dual planet systems like Pluto and Cheron, maybe that’s already too similar in size and life has no chance, maybe the median sentient creature in the universe has experienced a tide, or maybe not - anyways I dunno that much about exoplanets or astronomy in general so every thing I’ve said might be completely bonkers xD
There are some schools of thought that say that a large moon like ours should be a part of the Drake Equation, because without which life would have a very hard time even on supposed “garden planets”.
Another factor that is likely to affect civilizations is an easy source of energy, like oil. We got lucky, in that the evolutionary development in Lignin in plants - and the several million years needed for bacteria to catch up and be able to break it down - are what created those massive deposits of organic matter that became trapped deep in the Earth and modified into oil. Without that oil we are unlikely to have reached several milestones, including transportation, population levels, trade, high technology, and even access to space. And this would start affecting us several hundred years back, with steam engines.
But maybe that’s what normal civilizations go though before leaving their planet, and the abundant access to oil will cause us to destroy earth before we can leave it 🤔
I recall one paper that tried to analyze how long it would have taken to go from a pre-coal civilization in the 1800s to spaceflight, all without hydrocarbons from the ground, and they estimated over 8,000 years to develop sufficient biological sources of hydrocarbons that could advance tech enough to just get into orbit. And the planetary population would have never exceeded 2B in the process. Oil, gas, and coal have done a shitton to enable technology. Even something as simple as electricity requires significant hydrocarbons Just in the infrastructure, not to mention the production of electricity itself.
I like to imagine an alien “watcher” with a lifespan measured in billions of years who has been hanging out in our solar system since its formation. It finally decides to contact us humans and tells us that it saw our moon being formed from another planet smashing into Earth billions of years ago. “Yeah, we know - wanna see the movie we created showing it?”
I love that one of the characters in Iain Banks’ “Transition” tries to find aliens by spotting airtight -looking vessels (ships, vans,…) during solar eclipses, for this exact reason.
That was, perhaps, the weirdest, Iain M. Banks book I’ve read.
Hell yes it was weird as hell! It was also the most conceptually mind boggling (with all the gender and sexual fluidity on top of everything else). I felt from style of writing and tone it was very personal and intimate, guess thats why I liked it so much.
The weirdest book to me was feersum endshin (sp?), but I mean, we’re reading Banks “it was the day my Grandmother exploded”, so…
It sounds more like the moon is just earth spare parts. Like when I put things back together. Always a bin of extras that hang around in the back of the truck, sliding around and what not.
Forgetting Pluto and Charon, drag sees.
Those are more of a binary planet than a planet and satellite, to be fair. And that’s even before we get into the whole planet vs dwarf planet debate.
(For the record, I think Ceres should also count as a planet)
Ceres is the issue. People are pissed that they learnt the list of planets and now it’s different, but don’t realise the only viable options were to either drop the last one or add a bunch of them, some right in the middle.
And if Ceres is a planet, shouldn’t Eris be one too?
What is argument for Ceres and Eris being planets?
Hydrostatic equilibrium. Their gravity is enough to pull their mass into a sphere-ish shape.
Contrast to asteroids that are irregular.
Large round bodies orbiting the sun.
The same as for Pluto
Exactly. It would get real messy.
Due to tidal effects the moon is slowly getting further away from the earth, so we’re living at just the right time to see such spectacular eclipses
Just add some really massive thrusters to the Artemis 3 payload manifest and nudge it back every so often
Or detonate a nuclear waste dump to send it flying off into deep space. We’re 25 years overdue already.
Well technically Charon is bigger relative to its parent body but, y’know, Pluto isn’t a planet…
A-ha! So the real reason Pluto got degraded was so Earth could keep it’s biggest moon status!
Big Moon has gotta be behind this!
Always making waves…
Twin planets. Caron and Plato. Downgraded to dwarves because NDG sucks milky ways.
He might suck, but you know it wasn’t his decision right?
Yeah, but it’s fun to blame him. He was vocally parading the news and using it, as usual, for self promotion. So I let him have it.
Charon is still a moon, nobody upgraded it to dwarf planet.
I thought for an object to be a satellite it’s orbital point had to be located inside the body of the other entity.
That seems terribly unfair. Downgrades but no upgrades?
That’s messed up, right?
I’ve heard it both ways.
Found Gus.
The Whack theory still has some important exceptions, which is why there’s a Double-Whack theory, which also has exceptions.
“The moon was created this way” is an opinion.
“hypothesis”, rather than “opinion”, no?
Hypothesis:
- A tentative explanation for an observation, phenomenon, or scientific problem that can be tested by further investigation.
- Something taken to be true for the purpose of argument or investigation; an assumption.
- The antecedent of a conditional statement.
I’d agree if it was stated as “current thinking holds that” or “one theory is” not just “here’s how it happened”. The latter is an opinion.
In the fifth or sixth book of the Foundation series they follow a map to Earth that mentions a planet with huge rings and a planet circled by a giant moon. Throughout the universe, this combination was so unique you could identify the home of humanity among trillions of planets.
It’s a weird book but I’m glad I read it.
And the idea of such a big moon was part of why it was largely thought of as an unfounded myth.
And it shows how Asimov had zero conception of how ridiculously huge the galaxy is, though that’s just the storylines being a product of their time, probably.
Or he was writing a fiction and knew he could play fast and loose with scientific laws.
Asimov wrote non-fiction books about astronomy; I’m sure he knew as much about it as you do.
Nah, I read the whole series recently and for some details that bothered me looked up the how the science on that progressed. I can’t give you exact examples as I don’t remember details, but I do know that there’s a bunch of very mistaken assumptions that the series is built on that he had no way of knowing back when he started and had to keep going forward (remember, the series was written over several decades starting in the fourties) and also a bunch of errors where he could have known better but just messed up.
Okay. We both agree that you have access to information that some who died in the last century wouldn’t have known.
I mean, obviously? That’s not what I was saying at all. I think you misinterpreted my original post in a big way.
Well, Foundation and Earth is the fifth book of the Foundation trilogy… of course it’s weird.
Similar to the five book Hitchhiker’s Guide trilogy.
Adams had one more short story in the Hitchhiker’s universe, but debatable whether it’s technically part of the trilogy.
Wasn’t there one more book written in the world by a separate author? Or is that this one?
Eoin Colfer’s And Another Thing
That’s the one! Thank you very much.
Other than Adams’s radio scripts, the only other book mentioned on wiki is a book by Terry Jones (of the Pythons) based on a game that was based on the mention of the “Starship Titanic” from Life, the Universe, and Everything. I’d never heard of it before though.
I remember that. I played the game as a kid and, when I found out it was a book years later, was thrilled! After reading it, I was a bit disappointed, but it was fun.
Someone else in this is referenced what I was remembering:
Yeah, but the Foundation trilogy has seven books.
The last two being prequels.(Also it’s connected to the Galactic Empire trilogy, which does have three books, but was published in reverse order, and the Robot series, a four book duology not to be confused with Asimov’s other robot books, though it’s set in the same universe, and also to The End of Eternity, which is set in a different timeline altogether but is sort of a prequel to the whole shebang.)
Ah, the Douglas Adams approach.
But the moon size thing isn’t a coincidence, thats part of what makes solar eclipses so rare, the moon needs to be at the correct distance when it passes in front of the sun or it isn’t as impressive, and it does do that some times.
Total* solar eclipses. Mars has solar eclipses, just not very impressive ones since the shadows are so small, but you could actually look directly at the sun to see the shadow at that distance, without fucking up your eyes
Do they bother calling them “eclipses” or “transits?” Like we don’t say Mercury or Venus eclipse the sun.
“They”?
Here meaning the overall astronomy community.
NASA seems to call them eclipses, as well as several other Space Agencies that should be recognized as authorities here, I can only assume that is due to the fact that Phobos and Deimos orbit Mars, and Mercury and Venus don’t orbit Earth.
So evangelion was right?
Jokes aside, the probability of moonlike-moons forming in earthlike-planets should be added to drake’s equation and see what that begets.
Might explain a lot of the silence, at least for life as we know it
The drake equation is a bogus probability that really means ultimately nothing. I would put stock in anything it says.
Why is that?
The Drake Equation was not really meant to be used. The original purpose of the Drake Equation was to drum up conversations surrounding the first SETI. All it really did was condense everything someone should look for in a possibly human habitable world where aliens may exist. We have much better ways to calculate and search now.
I understand, thank you
