The moon is a bit of a mystery.

[arkain101]

I really am questioning what exactly the moon is. There is sever explanations.

 

1) It formed with the Earth ; ie from the same material that formed the Earth. Yet does not follow the same plane of rotation as the earth.

2) It was created during a collision with a large comet or planetoid with the Earth.

3) It was a rogue satellite captured by the Earth.

 

But there is so many discrepincies that can throw those ideas out of wack.

 

The composition of the moon is different than the Earth. The Earth has alot of iron, the moon has almost none. The age of the moon rocks and samples is older than anything on the Earth. So that totally rules out number 1 and most of number 2. Indeed, the differing compositions of the 2 bodies and their age difference really does rule out number 2. However, in support of debunking that arguement, the fact is there is no evidence that the Earth was ever involved in such a collision, and there is no debris left over orbiting the Earth. Another puzzling fact, the moon is the only satelite in the solar system which does not orbit a planet in the plane of the planets rotation.

 

Which brings us to number 3, the moon was a wandering planetoid that was captured by the Earth. Not only that, but was captured in such a way that the same side always faces the Earth, (thus the dark side of the moon). And the moon is the exact distance away to be the exact same apparent size as the suns disc. You can see that if you are fortunate to be in an area of totality during a solar eclipse. Taking into account the size of the moon, you know what the chances of this all ocurring naturally are? Well they are so close to being zero that it is considered the most unlikely of the scenarios. The odds are so astronomical as to be impossible.

 

 

he most startling evidence came on November 20, 1969 when the Apollo 12 crew, upon returning to the orbiter sent the lunar module (LM) crashing back down into the moon. The LM struck the surface about forty miles from the Apollow 12 landing site, where sensitive seismic equiptment had been left. It recorded something both astounding and unexpected. The moon reverberated for more than an hour like a bell. The vibration wave took 8 minutes to reach a peak and then decrease. At a news conference that day, one of the co-directors of the seismic experiment, Maurice Ewing, told reporters scientists were at a loss to explain the ringing. "As for the meaning of it, I would rather not make an interpretation now. But it is as if someone had struck a bell, say in the belfry of a church in a single blow and found that the reverberation continued for an hour." Dr. Frank Press of MIT added "None of us have ever seen anything like this here on Earth. In all of our experience it is quite an extraordinary event. That this rather small impact... produced a signal that lasted an hour is quite beyond the range of our experience." The phenomenom was repeated with the Apollo 13's third stage, which was sent crashing by radio command. This time the reverberations lasted 3 hours and 20 minutes.

 

So as of today we still dont know what the moon is. it is an unidentified orbiting object.

 

As for me I am begginning to beleive in ufo's and aliens at quite a confident level.

There is so many sightings, and history of ufo activity that it almost seems to be denail to throw it out of mind.

 

I think it is purely ignorant to make a beleif that we are alone without personally educating yourself with all the knowledge that is out there on everything. I dont mean mumbo jumbo nonsense information.. I mean things like our history, our ancestors and our extradinorary rate of evolution. They have just proved that every type of monkey now contains identical chains of dna or rather chromosones. The information can be found here http://www.scienceforums.net/forums/showthread.php?t=9484

[bascule]

Which brings us to number 3, the moon was a wandering planetoid that was captured by the Earth. Not only that, but was captured in such a way that the same side always faces the Earth, (thus the dark side of the moon). And the moon is the exact distance away to be the exact same apparent size as the suns disc. You can see that if you are fortunate to be in an area of totality during a solar eclipse. Taking into account the size of the moon, you know what the chances of this all ocurring naturally are? Well they are so close to being zero that it is considered the most unlikely of the scenarios. The odds are so astronomical as to be impossible.

 

"Once you eliminate the impossible, whatever remains, no matter how improbable, must be the truth."

 

-- Sir Arthur Conan Doyle, Sherlock Holmes

 

Yes, this is a highly improbable scenario. But so is ambiogenesis, and I'm willing to bet that there's a direct connection between the tidal forces of such a massive satellite and the formation of life on earth.

 

Of course "willing to bet" is hardly a scientific conjecture...

[swansont]

The composition of the moon is different than the Earth. The Earth has alot of iron' date=' the moon has almost none. The age of the moon rocks and samples is older than anything on the Earth. So that totally rules out number 1 and most of number 2. Indeed, the differing compositions of the 2 bodies and their age difference really does rule out number 2. However, in support of debunking that arguement, the fact is there is no evidence that the Earth was ever involved in such a collision, and there is no debris left over orbiting the Earth. Another puzzling fact, the moon is the only satelite in the solar system which does not orbit a planet in the plane of the planets rotation.

[/quote']

 

Your statement about compositions is misleading. The earth does not have a constant distribution of iron - most of it is in the core. The moon does, in fact, have a composition that is very much like the earth's mantle, so the collision scenario works quite well if it happened after the mantle of the earth had formed and the iron distribution was already in place.

 

Debris would either consolidate with the moon, fall back to earth, or perhaps have enough energy to escape - there would be no stable orbits for them other than the stable Lagrange points. So "no debris" really isn't all that surprising after several billion years.

 

As for the plane of rotation, that will be dictated by angular momentum. The moon is within 5 degrees of the ecliptic; I don't know how much effect the sun has on regulating this. It certainly has more effect on our moon than any other planets'.

[tony873004]

Even if the capture theory were true, the Moon wouldn't have to be captured in such a way that the same side would always face Earth. It could begin with a spin, but tidal forces would lock it to the Earth eventually.

 

I have a guess as to why the Moon has more large impact basins than Mercury. Assuming the giant impactor theory, as the debris cloud in orbit around Earth condensed into moonlets and the moonlets joined to form larger moonlets, eventually one of them was larger than the rest. This is the one that becomes the Moon. When it reaches almost is present size it has enough gravitational influence to eject many of the remaining moonlets out of the Earth / Moon system. This would include several sizeable ones in the 10s of km in diameter.

 

What would be the fate of the escaped moonlets? They would orbit the Sun in Earth-crossing orbits. They'd probably orbit for 100,000s of thousands - low millions of years before slamming into Earth or the Moon. This gave the Moon enough time for a surface to solidify and hence record the impact.

 

Mercury didn't have large collision that littered its orbit with timebombs, hence it has very few impact basins compared to the Moon.

 

Any thoughts?...

[whap2005]

"The composition of the moon is different than the Earth. The Earth has alot of iron, the moon has almost none."

 

There is a reason for this. In computer models that attempt to recreate a possible collision that could have created the moon, almost all see the collision as a glancing blow. Most of Earths iron is contained in the core so it's possible that most of the matieral that makes up the moon came from the crust and mantle.

[Jimbo]

"The age of the moon rocks and samples is older than anything on the Earth."

 

That may be becuase Earth has tectonic plates that are subducting below other plates into the hot mantle and melts the oldest parts of the plate. While at the same time new material is rising and hardening to take its place. After several billion years a lot of the oldest crust has been subducted under.

 

The moon is very small and cooled quickly after it was formed, so there are no tectonics to 'renew' the surface.

 

And/Or

 

Asteriods and comets from the solar system are believed to be older than the Earth. Evidence from dating of asteriods found on top of the Antartic ice. The surface of the moon is covered with these older meteours and space dust. On Earth, however, most meteourites burn up in the Earths atmosphere before it reaches the ground.

[CPL.Luke]

out of curiosity what do these simulations say happened to the rock that hit the earth originally?

[Anjruu]

"When it reaches almost is present size it has enough gravitational influence to eject many of the remaining moonlets out of the Earth / Moon system."

 

Interesting idea, but I am not clear on this point. Gravity is attractive, so how could it repel moonlets?

[swansont]

"When it reaches almost is present size it has enough gravitational influence to eject many of the remaining moonlets out of the Earth / Moon system."

 

Interesting idea' date=' but I am not clear on this point. Gravity is attractive, so how could it repel moonlets?[/quote']

 

The quote didn't say repel, it said eject. Not the same thing.

 

The interaction from multiple bodies may make for unstable orbits, while the unperturbed orbit is stable.

[cpwmatthews]

. When it reaches almost is present size it has enough gravitational influence to eject many of the remaining moonlets out of the Earth / Moon system. This would include several sizeable ones in the 10s of km in diameter.

 

Any thoughts?...

 

If the Moon had reached a noticable size, would it have ejected the remaining Moonlets or rather would it have attracted them?

[swansont]

If the Moon had reached a noticable size, would it have ejected the remaining Moonlets or rather would it have attracted them?

 

It's not an either/or question. An attractive force can eject something from orbit.