Did Earth's tilted axis change?

@metal-brain said
How can you see more than 50%? It is tidally locked.

@shallow-blue said
Libration. This is Lunar Science 101.

@Metal-Brain
https://www.wwu.edu/astro101/a101_lunarlibration.shtml

This one is a bit more explanatory.

@metal-brain said
Is it because one edge of the earth can see more of the moon on the same side and the opposite edge of the other side of the moon?

https://www.merriam-webster.com/dictionary/libration

An object drifting through space, no matter how massive, will have it's momentum and velocity changed by whatever hits it no matter how small. So if Earth gets hit by a watermelon its momentum and velocity will change very, very little; if it gets hit by a 500 Billion ton rock then that change will be much greater and over time may not be insignificant.

@sonhouse said
@Metal-Brain
https://www.wwu.edu/astro101/a101_lunarlibration.shtml

This one is a bit more explanatory.

@Metal-Brain
U B velcome🙂

@beowulf said
@Metal-Brain

Definitely a good theory.

An impact big enough could change the earth's axis.
If it hit directly into water/ocean the crater would be filled in by sand eventually.
A hit that caused the planet to go molten would also hide the crater.

The celestial body impact that created our moon sucked all the iron (most of it) out of the moon and it went into the Ea ...[text shortened]... That explains the remaining iron in the moon. Sort of.

Just a theory but definitely interesting 🤔

@Metal-Brain
There is evidence from the moon rocks brought back by Apollo astronauts, similar to Earth stuff.
Also there is evidence the core of Earth is bigger than it should be and they think that might be because of the planet that whacked Earth some 4 billion years ago, that the impact pretty much shattered BOTH planets and some of the debris coalesced to become the moon but a bunch of the core still was left inside Earth and that migrated to mix with our own core and we think our relatively strong Earthy magnetic field could be due to that mixture.

The more people going to the moon the more we will suss out how it came to be, no matter who gets there next, Chinese, Russians, Americans, any of them will publish in peer reviewed journals and would LOVE to be the first to find say water ice on the southern pole of the moon where they thing ice can live because at the south pole some craters are totally hidden from sunlight so it can be 300 degrees below zero F and therefore no evaporation or sublimation of water can happen so there should be city sized deposits of water there, that would mean a WHOLE lot to colonists there and if China is the country finding it you can be sure they would strut their stuff all over the world.

My little bit on Apollo was really great, one day a buddy I met living next door in a house we just rented in Alexandria Va, when I was working at Goddard Space flight center, we got to yapping and we said what do you, it turned out he also worked at Goddard as an Apollo geological technician, his job was to slice the moon rocks into thin slices for the scientists to study with a lot of instrumentation, now much better of course. He invited me to his lab, which turned out to be a vault that would stand up in Fort Knox and inside was his 'lab' and a diamond saw to cut the samples into thin slices.

ALL the collected moon rocks were there on shelves inside the vault and he reaches down to one on puts it in my hand and my jaw dropped maybe three feet🙂
My first reaction was, why can you put this moon rock in my bare hands?

He said, as soon as we open the hermetically sealed chests coming from the moon the surfaces of all the samples are contaminated which is why I have a job, slicing them up in thin slices and THAT slice is done in a clean room, which it turns out was the inside of the vault so the surface of THAT sample would be pristine.

I was awestruck to have a frigging MOON ROCK in my bare hands I can tell you that AND the sample LOOKED alien.