Metisette is a moon orbiting the gas giant Hesiod in the 23 Librae system . It has a mostly Nitrogen atmosphere, but Methane is present as a liquid, forming the rivers and lakes of the moon . The Kig-yar, Reth, used Metisette as a breeding grounds for hundreds of thousands of Unggoy, which would be used to seize the The Rubble, and, ultimately, to destroy Earth.
Reth's plans fell apart when the Unggoy breeding grounds, along with the Redoubt, were destroyed by the asteroids of the Rubble.
 List of appearances
- Halo: The Cole Protocol (First appearance)