The Nine

"More of your brother's Crows have entered the Cauldrons of Rhea. The Nine do not approve."

- Techeun

The Nine (often represented as the IX) are the enigmatic rulers of the Jovians, the worlds and people beyond the Solar System's asteroid belt. They reside deep within an alternate dimension in spacetime, the Unknown Space.

Overview
The Nine have made contact with the Last City via one of their agents, Xûr, who sells Guardians what he calls "trash" yet are powerful weapons; and have formed an alliance with the Reef. After the apparent release of Skolas, their loyalty is in doubt despite rumours to the contrary. Osiris had met with the Nine on Europa. According to Brother Vance, "He [Osiris] says the Nine are vulnerable every moment they touch our world." Prior to this, when he was Warlock Vanguard of the City, Osiris had sought after them to the exclusion of his duties.

Following the Red War, the Nine have taken an active interest in Guardians, and have began to host the Trials of the Nine through their proxy, The Emissary.

Identity
"I cannot explain what the Nine are. They are... very large. I cannot explain. The fault is mine, not yours."

- Xûr, Agent of the Nine

Very little about the Nine or the Jovian peoples is known due to the isolation of the outer Solar System. Multiple legends offer contradictory clues and hints as to their nature, but none have been proven. It may very well be that all have some portion of truth to them.
 * Former human colonies who made a compact with an alien force to survive became the Nine and/or the Jovians.
 * Deep-orbiting Warminds who survived the Collapse.
 * Ancient leviathan intelligences originating either from Europa or Titan.
 * The Nine originated from the Corona-Borealis supercluster.
 * The first Awoken, now transcended into mental energy moving along the Jupiter-Io flux tube.
 * Ghosts who exited the Solar System and studied the heliopause.
 * Remnants of the Darkness, broken by the Traveler's sacrifice, still seeking to destroy human civilization.
 * A viral language of pure meaning.
 * Imprints of a transcendent entity left behind after its complete destruction.

Trivia

 * The name, "The Nine" or "IX", is likely a reference to the "Ix" in Frank Herbert's Dune series, a fictional planet whose position from its sun inspired the name, ruled by the Ixian Technocracy. Ix was the primary provider of technology for the Old Imperium (or Galactic Padishah Empire) after the infamous Bulterian Jihad, which banned AI; ironically, Leto Atreides II used many of their creations later in his reign, a situation unthinkable in his early years.
 * Additionally it could also reference the Rings of Power in J.R.R. Tolkien's The Lord of the Rings trilogy—"Nine for Mortal Men doomed to die"—given by Annatar to corrupt nine powerful kings of men, of which three were Númenórean; the last three were noble survivors from an island kingdom that fell to evil and was destroyed.
 * Corona Borealis is a constellation, known as the "Northern Crown". It is made up of seven stars, one of Bungie's many references to the number seven.
 * Heliopause (also known as heliosphere) is the boundary between solar wind and external cosmic rays, effectively the outer boundary of the Solar System. Therefore, the "Deep Black" is outside of the reach of the Sun's influence.
 * The Jupiter-Io flux tube is a cylindrical section of Jupiter's magnetic field line which passes between Jupiter and Io. If it were able to be seen by the naked eye, it would resemble a tube of electromagnetic force between the two. Electrical current passes along this flux tube forming a circuit between the planet and moon, which ionizes the cloud of volcanic sulfur, oxygen, sodium and chlorine into a ring of plasma which surrounds the planet, boosting its already powerful magnetic field even further. The flux tube itself boosts radio emissions from Jupiter, making them increase considerably when Io's orbit brings it closer to Earth.
 * Some of Xûr's dialogue partly explains the in-universe legends behind the Nine, as he mentions that what Guardians do "is to speak in a language of pure meaning".

List of appearances

 * Destiny
 * House of Wolves
 * Destiny 2