Doisac

Doisac is the name of the Brute homeworld. It possesses three satellites (moons), named Warial, Solrapt, and Teash, and is the third planet of the Oth Sonin system. It can be estimated that Doisac is closer to Oth Sonin than Earth is to Sol because its surface temperature/climate is slightly more tropical, ranging from -15 C to 52 C (5F to 125.6F).

From limited details available about Doisac, it can be estimated that it's environment is very Earth-like, with forests and oceans. It has been noted, however, that its terrain is dominated by magma and magnetism, hinting at high tectonic activity and rich magnetised iron deposits.

The statement that Doisac is "Native Tier 4" refers to the "tiers of technological achievement" noted in the same Beastarium. Thus the Brutes had achieved Tier 4 (Space Age) levels of technology before becoming integrated into the Covenant's Tier 2 (Interstellar) technological systems. The planet was likely the site of conflict between the loyalists and seperatists.