Atmosphere
Also, somebody should include the fact that the atmosphere must contain oxygen, or the Elites would not be able to breathe in it, although the oxygen levels must be much lower than normal, since the Heretic Elites where respirators, suggesting that you need them for long term survival. Also there may be methane in the atmosphere, since the Heretic Grunts are breathing the light blue gas that is being mined.
Also the planet has a core of nitrogen or hydrogen.
Earth Survey Catalogue
Google and wikipedia doesn't reveal anything called the "Earth Survey Catalog", and I don't know of any mention of it in the books or games.--Raptor117 23:57, 28 February 2007 (UTC)
Yeah. Looking through the history, I think User:Dragonclaws added it. I have a feeling he made it up.