I think that's probably true. We know that "space magic" refers to the powers that Guardians have learned from the Traveller. It seems likely that when the Traveller arrived the effects of the "space magic" were greater than simply new powers. It is possible that it could have altered the characteristics of planets within our solar system. After all, "everything changed with the arrival of the Traveller."

Right on.

what if the hell mouth on the moon was the humans attempt at going to the center of the moon to put a core and then the moon would form an atmosphere and the humans could then colonize on then moon but half way into digging they uncovered the Hive and had to abandon the idea of civilization on the moon that is why there is a thin atmosphere. That is just a theory of mine but what do you think?

For a while I wasn't quite sure if they were talking about a thin thematic atmosphere or like a literal thin atmosphere, definitely by the end of that segment I was leaning more towards the former than the latter. On the subject of explaining stuff with Magic, as Joe Staten said in the GDC Presentation, it's not the job of the World Creator to answer every single question for the players, and in fact you are crazy if you even try to identify all the questions. Suspension of Disbelief is always healthy when it comes to playing a game, and there is definitely more power in leaving the answer up to the interpretation of the viewer than simply giving them a definitive answer. For example, [url=http://www.bungie.net/7_New-Destiny-Info-from-Ghosts-in-the-Machine/en/Forum/Post?id=62367116#referred-Destiny]last night[/url] I went to the Artists Reception for the Ghosts in the Machine exhibit in Seattle and I got to see plenty of thought provoking Concept Art pieces from Destiny, and meet the artists who brought them to life. I was talking to Dorje Bellbrook about "Last Stand", the concept art I linked above, because I thought the idea of walking along on Mars and seeing this ancient and ruined colossal golem hand just reaching up out of the sand as if its owner was breathing his last breath was wicked cool and dripping with story, and he commented that he honestly didn't even know the full story behind the hand, it was designed specifically to not have an answer but to have hooks to which you could attach story perhaps when the game launches or when a future game launches 10 years down the line or maybe even never! It occured to me then just how much the forums are going to be filled with rampant speculation after launch from the sheer number of unanswered questions supported by all kinds of details that will be dripping off of these environments. It's obviously a narrow line you walk between having to provide justification for outlandish things like and trying to keep the details hidden so the player can more fully immerse themselves in the world with curiosity, but unless the nature and origin of Space Magic is particularly relevant to the immediate narrative of Destiny, I imagine we might not get a direct answer about what it is exactly for quite a long while :)

Remember in the GDC presentation where they talk about the 'Souls' of the Fallen? The drive to answer these types of questions (What happened here? Where did everyone go? What can we find that they left behind?) is what sparks the imagination, provokes a player to continue exploring..