Osmiridia is a terrestrial planet roughly twice the size of Earth, but it is made of only light silicates and small amounts of aluminium oxide & has no iron core, giving it only 1.14 times earth's gravity.
Life arrived on Osmiridia roughly 65 Ma, after a very large asteroid containing Terran bacteria crashed into soft clay near the equator. Life then flourished creating the most sentient species on a single planet in the entire Milky Way Galaxy. 7 sentient sub-species co-exist on Osmiridia.
7 sentient sub-species co-exist on Osmiridia. Even though they are aware of their genetic differences they treat each other as equals, and since they are all fully genetically compatible with one another they even marry each other.They are currently in the Steel Age. They co-exist much like how Homo Sapiens once co-existed with Homo Neanderthalis. They are members of the Tri-Star Conferderation.