(covers information from several alternate timelines)
The Sol system (also known as the Terran system and Earth's system) was an inhabited planetary system in the Alpha Quadrant. It was located within a stellar cluster in Sector 001. The Sol system was the capital system of the United Federation of Planets.
Although it was most often considered to be part of the Alpha Quadrant, the Sol System was located at the boundary of the Alpha and Beta Quadrants. Star systems in its immediate neighborhood included the Alpha Centauri system and the Wolf 359 system. The Sol system was located about sixteen light years from Vulcan and less than ninety light years from Qo'noS. (TNG: "The Last Outpost", "The Best of Both Worlds"; ENT: "Broken Bow", "Two Days and Two Nights", "Home"; Star Trek: Insurrection)
Solar system maps
In 2267, "Chart 14A: The Sol System", which was stored in the Enterprise library computer, was a map of the Sol system. This chart was scanned by the probe Nomad in auxiliary control. (TOS: "The Changeling" production art)
In the 2270s, the location of Sol, and its largest planet Jupiter, was labeled on a neighborhood of astronomical objects, which was stored in the Enterprise library computer. This was one of the records scanned by V'ger. (Star Trek: The Motion Picture production art)
In 2293, the location of Sol was labeled in a map of the Milky Way Galaxy. This map was on a wall of Captain James T. Kirk's quarters aboard the USS Enterprise-A. (Star Trek VI: The Undiscovered Country okudagram)
In 2364, the location of Sol was labeled in a star chart, which showed the distance of this sun to neighboring stars in light years. This record was stored in the USS Enterprise-D library computer. The Portal of Outpost 63 scanned this record that year. (TNG: "The Naked Now", "The Last Outpost" production art)
An asteroid belt separated the system into an inner system and outer system. The inner system had four terrestrial planets: Mercury, Venus, Earth, and Mars. The outer system had four gas giants: Jupiter, Saturn, Uranus, and Neptune. The outermost terrestrial planet in the Sol system was Pluto. In the far reaches of the system, smaller dwarf planets existed. The system also contained a high number of comets, the orbits of which could take them both into the inner and outer solar system. (TOS: "The Cage", "Tomorrow is Yesterday"; TAS: "One of Our Planets Is Missing"; DIS: "The War Without, The War Within": Star Trek: The Motion Picture; Star Trek Generations)
- Known system locations
- Sol (primary star)
- Mercury (Sol I)
- Venus (Sol II)
- Earth (Sol III)
- Mars (Sol IV)
- Asteroid belt
- Asteroid colonies
- Jupiter (Sol V)
- Saturn (Sol VI)
- Uranus (Sol VII)
- Neptune (Sol VIII)
- Triton (moon)
- Pluto (Sol IX)
- Starbase 1 (space station; orbiting a dwarf planet)
|The Sol System|
|Mercury • Venus • Earth (Luna) • Mars (Deimos) • Asteroid belt • Jupiter (Io; Ganymede) • Saturn (Mimas; Rhea; Titan) • Uranus • Neptune (Triton) • Pluto|
Approximately four billion years ago, an ancient species of humanoids injected genetic material into the primordial soup on Earth. Five hundred million years later, life began on the planet. Besides Earth-based life, Martian fossils indicated that life also once evolved on other planets of the Sol system. (TNG: "The Last Outpost", "Datalore", "The Chase", "All Good Things...")
Approximately sixty-five million years ago, a comet collided with the planet Earth. With this mass extinction event ending the dinosaurian era, mammals rose to prominence. One of those mammalian species, Humans, forged a civilization on their home planet. By 2373 a small number of Voth scientists believed that their species originally evolved from hadrosaurs on Earth, before leaving the Sol system towards the Delta Quadrant. (VOY: "Distant Origin")
Starting in the mid-20th century, Humans began the process of exploring and colonizing their home system. In the mid-22nd century, amid the Xindi crisis, it was already expected that a residual presence of humans would remain in the Sol system, even after the total destruction of Earth. By the late 24th century, there were Humans living on Venus, Luna, Mars, and on the moons of Jupiter and Saturn. Terraforming efforts were under way to make planets such as Venus and Mars more hospitable for humanoid life. (TOS: "Return to Tomorrow", "By Any Other Name"; DS9: "Past Tense, Part I"; VOY: "One Small Step"; ENT: "Strange New World", "Azati Prime", "Terra Prime")
In addition to planetary settlements, habitable space-based facilities such as starbases and spacedocks had been built in orbits around Earth, Mars, Jupiter, and smaller planetary bodies in the outer Sol system. (VOY: "Relativity", "Life Line"; DIS: "The War Without, The War Within")
In 2257, the Sol system came under attack by Klingon forces near the end of the Federation-Klingon War. Members of the House of D'Ghor attacked and occupied Starbase 1, orbiting a planetary body in the outer reaches of the system. A short time later, a Klingon fleet moved towards Earth, only disengaging their attack after a sudden armistice had been declared by the new Chancellor L'Rell. (DIS: "The War Without, The War Within", "Will You Take My Hand?")
In 2293, the maiden voyage of the USS Enterprise-B was planned as a tour around the Sol system, with the ship traveling past Pluto and then returning to spacedock. However, the flight plan was abandoned when the Enterprise received a distress call from the SS Lakul. (Star Trek Generations)
In 2367, a Borg cube crossed the Sol system, easily eliminating the Mars Defense Perimeter, a last line of defense for the inner planets of the system. The cube was later destroyed in orbit of Earth. (TNG: "The Best of Both Worlds, Part II")
In an alternate timeline, all major inhabited planets and colonies in the Sol system were destroyed by the Xindi weapon. This ended when the Enterprise NX-01 crew sacrificed themselves to change the future by erasing interspatial parasites from Jonathan Archer, allowing him to remain in command and find and destroy the weapon. (ENT: "Twilight")
In another alternate timeline, the entire Sol system was destroyed in a temporal explosion when Henry Starling took the timeship Aeon from the 20th century to the 29th century without properly calibrating the temporal matrix. This event nearly happened but was stopped when Captain Janeway manually fired a photon torpedo from Voyager at the Aeon as it entered the temporal rift, destroying it and killing Starling. (VOY: "Future's End", "Future's End, Part II")
A map of the galaxy created for Star Trek: Deep Space Nine Technical Manual was reused on a PADD in the film Star Trek: Insurrection depicted the location of the Sol system.  The PADD prop was sold on It's A Wrap! sale and auction. 
The chart naming astronomical objects was from the Star Fleet Technical Manual.
The chart naming stars within twenty light years of Sol was drawn by Rick Sternbach for the Star Trek Spaceflight Chronology in the late 1970s. Found on page 77, this chart showed Earth commercial and exploration routes after the use of warp drive began. Sol was a stop on the Alpha Centauri-Epsilon Eridani commercial route.
According to Star Trek: Star Charts (Pg. 19), although the Sol system is located in the exact corner of the sector and was thus divided equally among all eight sectors, it is considered to be in Sector 001 for purposes of celestial navigation. Similarity, while the Sol system is divided equally between the Alpha and Beta Quadrants, it is considered to be part of the Alpha Quadrant.
The real-world debate on the status of Pluto as a planet was referenced in the novel Before Dishonor. Star Trek Online established that Sol has eight planets in the system's description. Both Pluto and the unnamed Starbase 1 planet are represented in-game alongside the other planets, indicating that the two are considered dwarf planets in the 23rd and 25th centuries.
According to The Worlds of the Federation, there was a tenth planet beyond Pluto.