Re: Tidal Motion

["Paul O. Johnson" <pojhome@SWBELL.NET>]

----- Original Message -----
From: "Jim Green" <JMGreen@SISNA.COM>
To: <PHYS-L@lists.nau.edu>
Sent: Tuesday, July 04, 2000 12:03 AM
Subject: Tidal Motion

> Is the nature of the Moon's core known?  Solid?  Molten?
>
> Does the Moon have a mantle?
>
> Is the magnitude of the tidal motion of the Moon's surface known?
>
> For that matter is the magnitude of the tidal motion of the Earth's mantle
> known?
>
> Which has the greater effect on the Moon's orbit the Earth's oceans or its
> mantel?

Jim,

I'm not a geologist but since the moon has no magnetic field, I would
imagine its core is solid.

I don't believe NASA has done the lunar seismic tests that would give a
picture of the moon's internal structure.

Ditto for the tests that would measure the tidal motion of the lunar
surface. But geologists have done many tests measuring the tidal motion of
Earth's surface.

Since Earth's mantle has a greater density than its oceans and since the
mantle continues under its oceans as well as under the continents, it must
have more total mass than the oceans and therefore exert a greater
gravitational pull on the moon.

Paul O. Johnson