Death Angels' Homeworld is an unknown planet that has never appeared in the franchise.
History[]
According to John Krasinski, the Death Angels' Homeworld was a hell world without a star so the planet was in a state of perpetual and total darkness. Given the lightlessness, the Death Angels’ evolved to use echolocation to see instead. The planet's life was harsher due to the planet having higher a gravitational pull than Earth's.
Prior to Day Zero or Day One of The Invasion, their planet was destroyed when it violently exploded. However, the explosion of their planet caused the planet itself to turn into a colossal amount of asteroid fragments that arrived at Earth in the form of a meteor shower. The asteroid fragments fell in multiple places/cities such as New York, Millbrook, Shanghai, and Mexico with the largest fragments arriving in those said countries.
Because the Death Angels‘ have indestructible armor over their entire body, the creatures survived inside the asteroid fragments upon atmospheric entry, and after the fragments split into hundreds of pieces and fell across the Earth. The creatures then emerged from the husks of their shattered planet and began to invade Earth by slaughtering unprepared Earth's population and causing the near extinction of most sapient life on the planet by hunting via noise.