Etos is the first planet from the sun of the Fair Chance Act (FCA)-protected Osiris system. Located on the innermost edge of the green band, it has a natural oxygen-nitrogen atmosphere and is inhabited by countless species, one of which, the Phare's Ape, shows strong evidence of sapience. Nearly all the animals on Etos live underground, in an extensive cave system that reaches down to the planet's mantle. While travel to the planet is prohibited, research teams are occasionally dispatched there to observe life in the caves.