Nessus

"Lush with giant twisted trees, deep caverns, waterfalls, and silver swamps, the origin of this planetoid remains unknown. What is clear is that the Vex have nearly transformed the entire planetoid into a Machine World, above and below the surface. For those Guardians willing to brave the dangers and explore the myriad of mysteries, treasures beyond the imagination await."

- Website description

7066 Nessus is a Centaur minor planet with an irregular orbit. At perihelion, Nessus is closer to the Sun than Uranus; at aphelion, Nessus moves into the Kuiper belt.

History
Approximately 126 years before the SIVA Crisis, Nessus re-entered the Solar System after an unexpected delay. At some point, the Vex, overseen by the Axis Mind Argos, Planetary Core, fully converted Nessus into a Machine World. The Leviathan is actively consuming the planetoid.

The Axis Minds of Nessus are noted to have higher than average computational power. One such mind imprisoned Failsafe for attempting to access the Vex Network. Sagira sought out another such Mind in order to analyze a map of the Infinite Forest.

During the Golden Age, the Colony ship Exodus Black crashed on Nessus on its way to Kepler-186. All of its colonists and crew were subsequently either captured and experimented on (such as stealing the memories of the captain) or killed by the Vex. Unable to contact help, the ship's AI, Failsafe, became dormant until she was awoken by the arrival of Cayde-6.

Following the Red Legion's invasion of Earth, they began to mobilize their forces across Nessus in an attempt to uncover any secrets it harbored. During this mobilization they came into conflict with the local Vex population as well as the Fallen House of Dusk which was scavenging whatever they could from the remnants of the Exodus Black.

Following the death of Dominus Ghaul, Calus' flagship, The Leviathan, began to consume the planetoid. Doing so caused Argos to be sucked into the Leviathan's vacuum alongside a squadron of Vex, forcing Calus to call upon the Guardians to be rid of the Vex Mind for good. Succeeding in destroying the Axis Mind, the conversion of the planetoid has been halted but the Leviathan continues to slowly consume Nessus.

Locations

 * Arcadian Valley
 * The Tangle
 * Well of Dust
 * Well of Echoes
 * Virgo Conduit
 * Chamber of Stone
 * The Mists
 * The Fissure
 * Ancient's Haunt
 * The Cistern
 * Pools of Luminance
 * Well of Flame
 * The Anchor
 * The Conflux
 * Excavation Site VII
 * The Inverted Spire
 * Watcher's Grave
 * Chamber of Water
 * Artifact's Edge
 * The Orrery
 * Hallows
 * Sunken Cavern
 * Well of Giants
 * Exodus Black
 * Chamber of Sky
 * Prodromus Down
 * Well of Stars
 * The Rift
 * Glade of Echoes
 * The Carrion Pit
 * EX-077 Command
 * Endless Vale
 * Arcadian Strand
 * Distant Shore

Trivia

 * The Vex who reside on the planet bear slight technological and physical differences from those across the rest of the Solar System.
 * Large parts of Failsafe's ship, the Exodus Black, can be found along parts of Nessus. Scannables in the area indicate that Failsafe's crew tried to escape and survive, but died due to a lack of food and supplies.
 * Failsafe's crew do refer to the presence of the Vex, suggesting that the cyborgs were present when they arrived. Failsafe referred to the fact that she had been on Nessus long enough to see the Vex take over the entire planet, convert approximately 92% of it into a machine world like Mercury, and kill all life forms.
 * Some birds and small animals can be seen flying over and around areas on Nessus. Plant life also exists there. It is unknown whether Nessus actually held life before the arrival of the Vex. Neither Ghost nor the other Vanguard members suggest that the Traveler terraformed it.

List of appearances

 * Destiny
 * Age of Triumph
 * Destiny 2
 * Curse of Osiris