Main Question or Discussion Point
Is our moon slowly receding? is it getting further from us? if so why?
They thought it would probably be dead, but all the evidence suggests there's significant residual heat closer to the core. There's probably some magma around a small iron core.Ok, I read the article, and they suggest that Moon, they believe, may harbor liquid core. But they never say what it could be. So, what it could be, magma? I thought that moon is geologically dead.
Since there isn't any magma around the Earth's large iron core why would you expect around the Moon's?They thought it would probably be dead, but all the evidence suggests there's significant residual heat closer to the core. There's probably some magma around a small iron core.
Just guessing here, but I _suspect_ that the disconnect may be a semantic one:Woah what? There's no magma around Earths solid core? References please.
Consult any basic textbook on geology. (I presume the routine on this forum is the same as on other forums i.e. the person making the extraordinary claim is the one required to provide the references, not the person stating the facts, so it's really up to you to provide references for the idea of magma around the core.)Woah what? There's no magma around Earths solid core? References please.
Luna "molten rock" aka "magma" is typically described as being deep, near the *solid* iron core.Just guessing here, but I _suspect_ that the disconnect may be a semantic one:
Earth's core is a solid metalic surrounded by a liquified molten iron (and some other heavy metalic crud) molten core.... thus the dynamo effect giving us that lovely magnetic field that keeps us from getting fried....
...as distinct from _basaltic magma_ (and a few other kinds) which is what is often what is meant in casual conversation when speaking of 'magma', notwithstanding more precise definitions and terminology.
If I am off base on what was meant, however, please call it.
Sounds about right. Of course a key assumption is that no other celestial body enters the system and adds angular momentum...I remember reading about the theorem (Tisserand's criterion rings a bell) that the moon will never actually leave the Earth's orbit, and is confined to within a certain orbital radius as a result of the findings of the circular-restricted three body problem. It was shown that the moon is in a stable orbit that will never reach a certain critical "zero-velocity surface", I think this is summarised in Moulton's book on celestial bodies. I don't know if the assumptions made are invalid in our system,