Undergrad How our Moon and Sun may affect Earth's equatorial bulge

[lunatectonics]

the equatorial bulge of a planet is affected by the planet's rotation and viscoelasticity of the sphere. Venus's rotation period is 244 days with an equatorial bulge of 0%. Earth's and Mars's rotations are almost identical at 1 day and 1.03 days, yet Mars's equatorial bulge is 6% vs Earth's 3%. Mars has has a colder mantle with viscosity estimated 10 - 100 times earth's viscosity.

Given that Earth's shell is more mobile and responsive to deformation , what would be Earth's equatorial bulge % if the Moon's tidal forces were not squeezing it ? the sun being constant with both Mars and Earth.

 

[russ_watters]

It sounds like you're saying you think the moon impacts the Earth's equatorial bulge, decreasing its size vs Mars'. The equatorial bulge is much, much larger than the tides (and exists around the entire equator), so it doesn't explain the difference. The difference is probably explained by the difference in size between the planets. A smaller planet has a smaller tangential velocity but a much smaller gravitational acceleration at the surface.

 

[256bits]

Mars's equatorial bulge is 6% vs Earth's 3%

To what are the 6% and 3% comparison referring.
Equator to North-South pole diameter, or something else.

 

[256bits]

It sounds like you're saying you think the moon impacts the Earth's equatorial bulge, decreasing its size vs Mars'. The equatorial bulge is much, much larger than the tides (and exists around the entire equator), so it doesn't explain the difference. The difference is probably explained by the difference in size between the planets. A smaller planet has a smaller tangential velocity but a much smaller gravitational acceleration at the surface.

The earth's Equator to North-South pole diameter bulge is more close to theoretical, and Mars is out is whack.
If anything, Mars needs explaining.