An aging UNSC vessel, and one of the smallest in the UNSC fleet. This ship, along with crew, Captain Keyes, and the Master Chief, crash landed on Halo. At the end of Halo, the starships fusion reactors go supernove, sterilizing the land, and creating a HUGE crater in Halo. Un able to with stand the forces exerted on the new weakpoint, halo breaks apart.
The smallest cruiser in the UNSC fleet, the Autumn is a Halcyon-class warship under the command of Captain Jacob Keyes. After the Battle of Reach, the Autumn made a blind lightspeed jump in an attempt to lure the Covenant away from Earth, and arrived at the fortress-world Halo.
The Pillar of Autumn fired several cannon blasts at the Covenant cruiser.