Earth's momentum and the moon

depends on the details ... basically the asteroids momentum would get added to the system.

 

Lets say we totally vaporize the moon. The mass is still there - maybe still gravitationally bound to the Earth. Depends on how we do it.

Strap a rocket to the moon and accelerate it out of orbit (actually, this is happening - albeit slowly) ... maybe we use materials found on the moon so we don't have to worry about the effect of launching a billion nukes from Earth.

You can probably work that out - put two masses in orbit about their common center of mass, give one of them an extra radial velocity. See what happens. That would be a good exercize for you ... builds character ;)

Then the nuke option - this would be treating the Moon as a cue ball and smacking it out of orbit. The Moon vaporizes ... but maybe all the bits acquire escape velocity in the right direction to leave.

That would be like the slow version, only very quickly.

Magic the Moon out of existence but insist that angular momentum is conserved?
Then the Earth would have to gain angular momentum to compensate ... also by magic. The kicker with these things is to consider the process.

I am hoping this is idle curiosity?

 

To carry it further, the Earth spin axis is now wobbling around in a precession cycle of about 26,000 years, this precession is caused by the gravity difference of the equatorial bulge in relation to the sun and moon, causing a torque. If the moon was gone the precession rate would be much slower, how many years?

There is also an obliquity cycle of about 41,000 years. It is hypothized that when frequency of both precession and obliquity are approaching each other, resonance will bring the planet to extreme obliquities, known as the chaotic zone, where is our moon when this start to happen?

 

Would detonating a nuke on the Moon be as effective as on Earth, due to the lack of atmosphere.
Would the blast just radiate into space and have no effect on the Moons orbit ?

As for the Earth and Moons centre of mass (below the Earth's crust), Would landing on the Moon and leaving the lander behind (Mass) have an affect on this ?

 

@Martinaston: welcome to PF;

1. depends what you mean by "effective" - what effect were you thinking of? Certainly the atmosphere means there are extra effects.

2. the kind of blast that would have a noticable effect on the Moon's orbit would also do serious damage to the Moon.

Phil Platt did the math for a much bigger explosion, but it tells you what sort of calculations you have to do.

3. By going to the Moon and leaving stuff behind, you are effectively moving mass from the Earth to the Moon (though Apollo missions also brought mass back from the Moon).

You can get an idea of the scale of the effect by working out how much mass you'd have to move to get the center of mass between the Earth and the Moon to sit on the surface of the Earth. It's not a hard calculation. Then, looking up how much mass got transferred in each Apollo mission, you can work out how many missions this would have taken.

 

@mfb

Describe "not a significant amount" after 43 years + however much more junk is up there from all the other probes/landers, please.

I'm kind of more interested in the shift of tidal forces withing the Earths mantle.

@Simon Bridge
Thanks and helo.

1 i was thinking along the lines of the dam busters, when they used the surrounding water pressure to concentrate the blast into the dam.

Would it reduce the effect of the blast wave, not having the atmosphere to help contain it against the Moons surface ?

3, as per my reply to mfb