Laughable. This concept has nothing to commend it, in particular no observational or experimental evidence. I'd like to see a modeling of that "coalesced to form the Moon" part. It would be better for scientists to admit they don't know than fill the discussion with so many wacky ideas.

The Giant Impact Theory on the surface seems plausible, but under the slightest scrutiny becomes far fetched at best. You can throw as many fancy animated models into the vacuum as you please but it simply can not hide the fact that we don't have a clue how the Moon came to be.

Would that same theory hold true for the moons of other planets? What about Gas Giants like Saturn and Jupiter?

What other logical explanation is there?

The impact threory seems inconsitant with what we observe about moons of the gas giant planets. Many of these are rocky moons, and one would not expect production of such moons from an impact of something into a gas giant. There has to be some other type of "moon production" process that applies to those planets as well as Earth.

First of all, I love Reddit. Second of all, there is a significant amount of evidence to support this theory. 1. The same side of the moon continuously faces the earth throughout its orbit. Another way of saying this is that its rotational and orbital periods are exactly equal. If the moon had been captured (as most other moons in the solar system were), its rotational period would have been determined before it got to the earth, while its orbital period would have been determined by the interaction of its mass with the mass of the earth. That these two quantities would happen to match so perfectly would be a coincidence beyond belief. If the moon was created in the way described by this theory however, it would be entirely possible. After the mars-sized body struck the earth, it added its rotational momentum to the earth. The moon and earth are now essentially one system with a common quantity of rotational momentum. It just happens they are two bodies separated by empty space. 2. The earth wobbles. This is not the wobble created by the gravitational pull of the moon. It is some other wobble. This slight wobble can best be explained by us being hit by something really big. A mars-sized asteroid would have done it. 3. The moon is really big. Its diameter is about a quarter of the earth's diameter. The moon is much much much larger (in comparison to its parent body) than any other moon in our solar system (I'm talking to you, Joe Astronomer). It is so big that if it had come close enough to be captured in Earth's gravity well, it would have given the earth a much more eccentric orbit than we have. As it is, the wobble in the earth's orbit is very slight, and better explained by my third point. 4. We went to the moon, and its made of the same minerals we find in the earth's crust. Once we actually went to the moon and found this out, it pretty much sealed the deal. The moon is made of Earth.

just wondering, are any of you astronomers or geologists? please feel free to contribute something other than rhetorical horseshit if you are.

Gas giant moons were not formed the same way as our moon. Those were likely formed on their own, but were too small to become full-fledged planets and became attracted to the gas giants. Notably, none of the other rocky planets have true moons. The moons of Mars were likely captured in the same was as gas moons.

Yeah, gas giants 'capture' their moons. Some are also made of 'ring' material left over from collisions with captured moons or with the planet. Which of these two is likely to explain earth's moon? We don't have enough gravity to 'capture' a body the size of our moon very easily.

To all those commenting about gas giants moons, this would not be the same theory used to describe them. Most of those are believed to have formed by them grabbing passing by bodies. They are massive enough that they could grab a passing meteor or that they even form the moons themselves, the Earth however is not large enough nor does it form fast enough. That is why there is a search for a different way in how the Earth's moon was formed.

Things to think about: 1. The moon is 400x closer than the sun and 400x smaller. Not 399 or less, not 401 or more. It covers the sun almost perfectly during an eclipse, what are the odds? 2. Why are there more impact craters on one side of the moon than the other? (the side towards us) 3. When Apollo 13 released the Command Service and Lunar modules, they caused them to crash into the moon. Seismometers left by Apollo 12 reported an impact echo, with the moon ringing like this for over 3 hours. Hollow? 4. Apollo astronauts reported lights on the surface of the far side of the moon.

Oh Hai, I am neither a geologist, nor an astronomer, so you'll have to deal with rhetorical horseshit for now. Unless you yourself have something more appealing. Are there any tired internet catch phrases that could help us out?

"just wondering, are any of you astronomers or geologists? please feel free to contribute something other than rhetorical horseshit if you are." Hello. My degree is in geology, but you'd be better off asking a physicist, or someone who deals with the pure mathematics behind gravity and collision of objects. We (geologists) mostly deal with earthly movements of rock, etc. Unless a schools course offerings were much different from the traditional degree, most geologists wont be able to help you at all here ;)...besides the same horseshit the rest of the folks are typing. As for my opinions on the whole thing: I think computer technology will lead us to a very reasonable model for how everything formed. Of course it won't be exact, but it will likely be accurate, with the number-crunching ability of modern science. Models are fantastic generalizations once all of the laws are in place

Lance: Your first point is easily explained as Tidal Locking. Your 2nd point does not imply anything related to the moon. It certainly isn't evidence for the theory asserted in the video. Likewise for your 3rd point - it simply shows (assuming your assertion is true) that it's unlikely that the moon was captured, not that it was created in the way asserted by the theory in the video. The 4th point you made is the only evidence I can see in support of this theory.