Chi Ceti IV

Chi Ceti IV is a planet in the Chi Cert System. The planet has a top-secret installation on its surface, known as the Damascus Testing Facility, where the SPARTAN-IIs were upgraded with their refined Mark IV MJOLNIR armor during the Battle of Chi Ceti.

The facility and a UNSC training center was abandoned and, those being the only known Human installations on the planet, it is quite unlikely that the planet was destroyed and glassed by the Covenant ensuing the evacuation. When the Covenant attacked, the SPARTAN-IIs boarded their ship, and Samuel-034 died in the process. The MJOLNIR Powered Assault Armor/EOD variant was also developed at the Damascus facility in this system.

Trivia

 * A distant red nebula is visible from the system.
 * A planet from Bungie's previous game, Marathon, takes a similar name. This name being Tau Ceti IV.