Ariel

Ariel is a Human colony world of the United Nations Space Command. The planet has two archaeological dig sites and one settlement, with a population of approximately 4000 residents.

During the Human-Covenant War, the Covenant invaded the colony, and one of the civilians managed to send out a distress signal, to which UNSC High Command sent a force of Orbital Drop Shock Troopers from the 105th ODST Division to investigate. The UNSC forces came to notice that the Covenant were not operating in their usual fashion; Glassing of the planet was not their intent, but they were searching for something under the surface instead.

The object the Covenant sought was discovered to be a Forerunner A.I., which called itself "The Knowing". Shortly after being found by the ODST squad, it self-destructed. As a result, the Covenant fleet broke off their attack, not even wasting the energy required to glass the planet.

Trivia

 * Ariel is also the name of the planet Uranus's fourth largest moon.
 * Ariel is also the name of a planet in the television series Firefly, which starred the voice actors for Buck, Dutch and Mickey (being Nathan Fillion, Adam Baldwin and Alan Tudyk, respectively).

List of appearances

 * Halo: Helljumper