From Halopedia, the Halo wiki
Ansket IV is a terrestrial planet orbiting the star, Ansket. It was the site of a Covenant Hydro-processing facility prior to being abandoned by the empire. The United Nations Space Command established a forward operating base at the site of the Covenant facility. In 2553, this UNSC base came under attack by the Banished.
The Covenant constructed a hydro-processing facility on Ansket IV at some point prior to its undoing in late 2552. This facility was eventually abandoned and the United Nations Space Command established a forward operating base at its location. In mid-2553, the Jiralhanae warmaster of the Banished, Atriox, persuaded the Sangheili shipmaster, Let 'Volir, to defect to his cause. During their escape from the shipmaster's former fleet aboard 'Volir's CAS-class assault carrier, Enduring Conviction, he made Atriox aware that the vessel was low on fuel. Since they would likely be unable to replenish their supply at any other hydro-processing centers without triggering conflict with vestiges of the Covenant, Atriox directed the shipmaster to set a course for Ansket IV.[note 1] Upon their arrival, Atriox suggested that in addition to providing for their needs concerning fuel, the human presence on the planet could keep 'Volir's warriors from growing bored. In accordance with the Jiralhanae's command, an assault was launched on the humans.
Topography and ecology
Ansket IV is covered with an abundance of liquid water, but is devoid of any native sentient life. From orbit, its oceans appear blue and its multiple continents display shades of green and brown. Ansket IV is the fourth planet from its star and is orbited itself by at least one natural satellite.
List of appearances