With a twenty-seven-hour oblique rotation, Utapau completes a lap around its sun once every three hundred and fifty-one days. On the surface, Utapau appears to be a stormy, inhospitable world of stark, sandblasted wastes. But below the surface, life thrives in a unique environment of immense interconnected chasms and hypogean seas. Evidence indicates that Utapau was once an oceanic world with a standard axis, but an unknown event caused the planet to shift onto its side and shed its numerous moons. Sedimentary rock collapsed, and the ocean drained into a vast network of subterranean magma chambers, creating the underground world-ocean that exists today. Only the polar ice still clings to the surface, giving Utapau the false appearance of an arid world where life must struggle to survive.
The Utapauns colonized this world fifty-seven thousand years ago, although the ancient Kilik hive mounds which dot the surface indicate that they were not its first settlers. While some dwelled upon the surface, other colonists delved into the underworld, and over the course of millenia, these groups evolved into the two distinct races that we associate with Utapau today: the Pau`an and the Utai. Ten thousand years ago, the planet's changing weather patterns began to reach tremendous strength, producing occasional hyperwinds that posed a threat to the surface-dwelling Pau`ans, forcing them to seek refuge in the sinkholes alongside their Utai cousins. These periodic whirlwinds gradually stripped the planet of large trees, inspiring the development of the unique Ossic tradition of architecture, which utilizes the skeletons of native ruhau-whales.