Verge

Verge was a UNSC colony world. The colony had at least one major human settlement, Cuidad de Arias. The planet was known to have needed extensive terraforming in the past, including artificial elevation of the crust, resulting in concentrations of helium-3 being trapped in the mantle.

History
During the Human-Covenant War, Verge was conquered by the Covenant. The city of Cuidad de Arias was one of the hardest hit when the Covenant attacked the planet. The Covenant would set up a Beacon there to extract helium-3 from the planet's mantle for conversion into pure energy, which was transmitted to orbiting Covenant satellites and then transmitted wirelessly to ships blockading Tribute in the Epsilon Eridani System. The Beacon was destroyed by Team Black, also accidentally liberating a Yanme'e penal colony in the process.