fucks me up that by total coincidence the sun and moon’s size difference is exactly matched to their difference in distance from us, thus making our beautiful total solar eclipses where you can see the silver threads of the sun’s corona possible because the moon just covers the sun completely
The stars (literally) aligned just right for this experience to be possible. It’s likely that aliens don’t have this
The moon is also absolutely gargantuan by moon standards. It isn’t the largest moon in the solar system, but it is BY FAR the largest in comparison with its planet. Ganymede is the largest satellite of Jupiter and the largest moon in the solar system. Its diameter is only about 3.8% of Jupiter’s. Titan’s radius is 4.4% of Saturn’s. Callisto and Io are the next largest in the neighborhood, with 3.4% and 2.6% the diameter of Jupiter respectively.
Our moon is number 5. It is smaller in direct comparison to the above moons. The diameter of the moon is 3475 km. That is a full 27% of the diameter of the Earth. More than a quarter. That’s ridiculous. It’s unheard of. The universe is large enough that the word unique probably doesn’t mean a lot, but this might be about as close as you get.
This has had a huge impact on our planet. Other things aliens might not have are significant tides. One of Mars’s dumpy little potatoes wouldn’t be able to move oceans the way our moon does.
Our moon has also stabilized our axis to a massive degree. Without her up there our axis would wobble all over the place and our climate would be far more chaotic. Aliens might not be quite so lucky.
I guess what I am really trying to say is that the moon is extremely cool. I like the moon.
Just want to add that the reason we have such a large moon is because a whole planet crashed into proto-Earth. Theia (the planet) and Earth got so superheated by this collision that their component cores fused and the impact jettisoned a lot of material into space. That massive amount of jettisoned material became our moon. So Earth and the moon have very similar composition. This does not seem to be a common method of lunar formation.
what if the answer to the fermi paradox is that life cant exist without a moon like luna
That has been seriously suggested, yes. The moon has helped shield our planet from asteroids and the tides have kept the oceans mixing, and it’s an open question how important that stuff is to having life survive long enough to get all smart like us.
Maybe alien worlds could have had life, but they had no moon (or small moons) so their oceans went stagnant and any life that did evolve got clobbered by a ton of rocks from space that didn’t end up hitting the moon instead.
Jupiter helped too, since it’s the big sibling of the solar system that catches a lot of the asteroids, but wow, yeah. Things would have turned out very different without our moon.
