Doisac
From Halopedia, the Halo wiki
Doisac is the name of the Brute homeworld. It possesses three satellites, named Warial, Solrapt, and Teash, and is the fourth planet of the Oth Sonin system. It can be estimated that Doisac is closer to its Oth Sonin than Earth is to Sol because its surface temperature/climate is slightly more tropical (ranging from -15 C to 52 C).
It can also be noted that Doisac's environment is much the same as Earth's (although completely covered in tropical rain forests), though it has been noted[1] that its environment is dominated by magma and magnetism. Its shape and color is like that of Earth and Eayn. However, the left-side is covered red, presumably by lava.
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.[2]
