Algolis (Earth-5875)

Algolis was a human Inner colony, in the binary Algol system. It was home to a small population of 500,000 inhabitants and the Weapons Research Facility T12A, a facility that housed multiple prototype weapons and projects of the Office of Naval Intelligence, such as the HRUNTING/YGGDRASIL Mark I ADS.

History
The planet was home ot many facilities of the Office of Naval Intelligence, where many precursors of the chemicals used in the SPARTAN-II Enhancement Program were sent without the knowledge and consent of Dr. Catherine Halsey, to be later used in Project CHRYSANTHEMUM.

Algolis fell under attack of the Covenant on July 2548, starting the Battle of Algolis. During the firefight, the UNSC Marine unit Hades Corps were tasked with demolishing the Weapons Research Facility T12A to prevent it from falling into the Covenant's hands, while the last civilian survivors of the planet were evacuated. The UNSC The Heart of Midlothian was en route to the planet to secure the base's HRUNTING/YGGDRASIL Mark I ADS before it was attacked. All Covenant forces attacking the base were pulverized by the sacrifice of Ghost, who activated the Mark I's self-destruct system.

Notable inhabitants

 * Paul DeMarco