Hi, Adam.

My physics book mentions all theories (thankfully, makes me feel younger) and in regards to the capture theory, it states that it could be possible, but that "formation of the moon in a different part of the solar system, followed by capture by the earth - has no obvious flaws. The only objection to this theory is that it constitutes an extremely improbable event. For capture to occur, the moon must have moved past the earth at exactly the right distance. If too far away, it would have been whipped around the earth by the force of our gravity. without dropping into orbit; if too close, it would have collided with us. Calculations indicate that the range of conditions that can lead to capture is very narrow, and the probability of a capture occurring is correspondingly small. (Jastrow & Thompson)" IOW, the chance is there, but boy what a capture! The collision theory probably fits in there somewhere, yet I've wondered why there's no evidence left as in at least a faint ring unless both bodies were close enough and generated enough gravity to suck up most of the debris.

When our solar system was young, anything could have happened and obviously did.