Halo Alpha
Halo Alpha

Ariel is a Human colony world of the Unified Earth Government.


It was once the site of a Forerunner artifact named The Knowing used to store information.[1]

Human Colonization[]

Under human occupation, the planet had two archaeological dig sites and one settlement, with a population of approximately 4000 residents.[1]

In 2532, several SPARTAN-II augumentation chemicals precursors were sent to an ONI Section 3 laboratory on this colony.[2]

Battle of Ariel[]

Main article: Battle of Ariel

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.[1]


  • 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).
  • There is information in Halo Encyclopedia that Spartans wearing MJOLNIR mark IV armor were sighted. Suspiciously, that armor possessed energy shielding, thus it wasn't confirmed by ONI.