Sector Y is one of three strange nebula located in the Lylat System. It was the location of a major battle between Corneria's main battle fleet and Andross' forces during the Lylat Wars and later battles.
Sector Y is part of a trio of nebula that appear in the shape of a letter, itself formed in the shape of a giant Y. Though not as severe as those found in Sector X, radiation storms and fluctuating magnetic waves make travel through this sector dangerous, as the ionized space dust causes equipment malfunction or failure in most ships. It is thought by some scientists that the harsh state of Sector Y is the result of a failed Death Egg that underwent nuclear meltdown, polluting the sector with the radioactive fallout.
During the course of the Lylat Wars, the main Cornerian battle fleet engaged in a desperate melee with Venomian forces at Sector Y. The fleet took heavy losses when Andross' latest invention, large humanoid battle suits, were employed en mass to devastating effect. Highly maneuverable and protected by thick physical shields plus wielding laser pistols, the robot troopers supported by the Dorisby and Grazan capital ships threatened to overwhelm the Cornerian fleet.
The timely arrival of the Star Fox team saved the fleet from certain destruction. Plowing through the enemy fleet, the team confronted the flagship Saruzin, protected by two Shogun Warriors and Shogun itself. Fox McCloud succeeded in destroying the giant robots, breaking the back of the attacking fleet. The Cornerian Army was able to mop up the remaining enemies.
Sector Y was the site of a major battle during the Second Lylat Wars. Here, the Cornerian Defense Force lost a significant amount of fighters to the Venomian Army. This battle was the testing ground for Venom's new weapon, the Shogun Warriors. [hhttp://starfox.wikia.com/wiki/General_Pepper General Pepper] ordered Team Star Fox to aid the Cornerian forces and take out the robot soldiers. The team led by Fox McCloud destroyed the soldiers and the Androssian ships in their way until they encountered the Saruzin which was the base of the main Shogun robot. The team defeated the robot and headed for Aquas depending on where Pepper needed them next.
During the Aparoid Invasion, Pigma Dengar, who was being pursued by the Star Fox team, fled into Sector Y after escaping through Meteo. The team caught up with him and destroyed the Aparoid-infected Pigma.
The Star Fox team again fought at Sector Y during the final moments of the Anglar invasion in one of the endings. Fox McCloud and Falco Lombardi traced Wolf O'Donnell, who had stolen the device made by Andross to neutralize the Venom Sea from Titania to Sector Y. However, it was a trap as they were surrounded by Anglar forces.
- Sector Y possesses green in Star Fox 64 and the 3DS version of Star Fox 64 3D. However, in the Wii version the Y shape is now dark blue and is surrounded by blue and orange gas. But in Star Fox Command, the only sector regains its original color.
- Cornerian scientists believe that Solar's being in the middle of the three sectors is the reason for its molten state.