The Moon

[notb665]

If the moon came from the Earth, whereabouts? Is there a crater somewhere, or a big dent?

 

[Igorian]

Are you on some mission to break the record for the number of posts started in one day?

 

[notb665]

I have been ordered by the missus to take a break from DIY.

 

[2scoops0406]

Well apparently, according to the theory, two very large bodies collided, the collision didn't produce a crater, but caused both bodies to become molten and combine, with a largish amount of molten material being ejected. The larger molten mass became the earth, and the smaller amount of molten material became the moon which was captured by the earths gravitational pull. That's the theory anyhow.

 

[Steve]

so how did the moon turn into cheese?

 

[Richardp]

so how did the moon turn into cheese?

what was there first, the mice or the cheese ? and if you lived there how long would it take to get fed up with cheese ? is it soft melted cheese at the core then soft Camembert type in the middle and chedder on the surface ? so many questions so little time to eat it

why doesn't your wife want you to do any DIY ? have you destroyed your home?

 

[empip]

She overheard this .....
Two guys are in a bar. they find out they have the same wedding anniversary.
One asks the other "what did you get your wife for your anniversary?"
The other man replied," A Jag and a Mercedes."
"wow that weird why both?"
"Well if she doesn't like driving the jag she can drive the Mercedes. What did you get your wife?"
"A pair of slippers and a vibrator."
"wow that's really weird why?"
"well if she doesn't like the slippers she can go f herself!"

 

[Richardp]

wash your mouth out with soap and water

 

[notb665]

why doesn't your wife want you to do any DIY ? have you destroyed your home?

'Cus I have been doing too much, and have become ill.

 

[empip]

wash your mouth out with soap and water

Blue skies shining above, nothing but blue skies..... What unusually dry weather we have at the present... Just right !!

 

[Richardp]

well, that's a shame specially with christmas coming up hope you get better very soon.

 

[Big_Spark]

If the moon came from the Earth, whereabouts? Is there a crater somewhere, or a big dent?

Notb..the current theoru is that two Bodies existed in almost identical orbits, the larger one was the proto-Earth and simulations indicate it weighed about 1.2 times that of our current home and was slightly larger. The second body was likely about the size of Mars, roughly half that of Earth.

Anyway, the simulations that have been used for the current incarnation of the theory indicate that both planets likely formed within 500,000 to 750,000 km of each other but in seperate orbital tracks. The larger body exerted a large gravitational effect on the smaller and over a couple of hundred million years they may have become co-orbital. This part of the theory is controversial, but the simulations do seem to indicate this happened prior to the larger body forcing the smaller one into a gravitational dance that saw it become an effective, though not true, satellite of the larger. However the orbit is degraded over a period of time due to gravitational interactions and the fact that both bodies would still have been accreting matter at some considerable rate.

Anyway, the simulations indicate that the orbit, once entered, quickly decayed and the two bodies drew inexorably closer together. Normally the larger body would eject the smaller and no collision would occur, however as the smaller body actually orbited the Sun still as a seperate body, the velocity of closure was such that gravity played little part except to close the gap.

Eventually the smaller body reached the proto-Earth's ROCHE limit and tidal forces from the larger body began to mechanically destablise the smaller one. However this body was travelling too fast for it to be torn to pieces, as a smaller body would have been, instead the two collided, it what may have been the largest impact in the solar system's history.

The smaller body was totally vapourised, and an equivelent mass of the larger body would also have been vapourised, expanding upward and outward, as it had nowhere else to go, the massive plasma and debris cloud would quickly expand beyond the gravitational influence of the remaining mass. Approximately 30 to 40% of the vapourised material would have been totally lost into space and would become dust, gases and larger particles in the inner solar system.

The remaining matter did a couple of things, the bulk of it was gravitationally bound to the larger body, and was soon re-accreted into it, however a large mass was left in an orbit about 40,000km above the surface of the larger body, far enough outside the Roche limit for effective accretion to occur.

Over a period, some think may have been as short as 1000 years, but may have been several million, the material slowly accreted into a solid body, but one so large that is had serious ramifications for the larger body. Instead of forming a planet/satellite pairing, what was actually created was a double planet in effect. The gravitational interactions began instantly and inexorably the body we call the Moon has moved away from the one we call Earth.

These motions are causing rotational and axial changes to both bodies, most notably in the Moon's case by forcing it to complete an orbit about their common centre of gravity in exactly the same period of time it rotates on it's axis. This is known as Gravitaionally Locked to it's parent body.

The larger body (Earth) that remained never had a crater as a result of this collision as the material was re-accreted and the body, being largely moltan on the surface due to the impact rate and massive volcanism, simply hid all signs of it from view.

Hope this helps.

 

[empip]

well, that's a shame specially with christmas coming up hope you get better very soon.

You not 'taking cover' down the shed, contemplating the brush... by any chance?

 

[Thermo]

so where did all the milk come from to make the moon then?

 

[joe-90]

Did you know the moon landing was a fake?

joe