(covers information from several alternate timelines)
The Sol system (also known as Solar system or Terran system) was a planetary system. This system was located in a stellar cluster in Sector 001 (or Sol sector), which was a region of space in the Alpha Quadrant. (For the Borg, the spatial designation for this region was Grid 325.) This system consisted of a primary, named Sol, and nine planets. The third planet, Earth, was the homeworld for a warp capable species, the Humans. The Humans had colonized Earth's only natural satellite, Luna, and the planets Venus and Mars, and the moons of Jupiter and Saturn. Other planets in the system were Uranus, Neptune, and Pluto. An asteroid belt in this system was a natural border between the inner and outer systems. This belt was located between the orbits of Mars and Jupiter. (ENT: "Terra Nova", "Terra Prime"; TOS: "The Cage", "Wolf in the Fold", TNG: "Conspiracy", "The Best of Both Worlds"; Star Trek Generations; VOY: "Dark Frontier")
The location of the Sol system in the Milky Way Galaxy was depicted on a Federation star chart in 2293. This system was located near Tau Ceti, Alpha Centauri, and Sirius. (TOS: "The Cage", Star Trek VI: The Undiscovered Country) The location of the Sol system was also seen in a viewscreen chart displayed by the USS Enterprise-D library computer. (TNG: "The Naked Now", "The Last Outpost", "Datalore", "Conspiracy")
A graphic depicting the Sol system was displayed in the office where Rain Robinson worked, at the Griffith Observatory in California in 1996. The same graphic was displayed in Deep Space 9's classroom in 2370. (VOY: "Future's End"; DS9: "Cardassians") Deep Space 9's classroom featured a painting of four planets of the Sol system including Earth and Saturn earlier. (DS9: "The Nagus")
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 USS Voyager at the Aeon as it entered the temporal rift, destroying it and killing Starling. (VOY: "Future's End", "Future's End, Part II")
- Earth (planet)
- Burke (comet; crashed into Mars 2155)
- Mars (planet)
- Asteroid Belt
- Jupiter (planet)
- Saturn (planet)
- Uranus (planet)
- Neptune (planet)
- Halley's Comet (comet)
- Pluto (planet)
"The Explored Galaxy"
This chart was first seen, chronologically, in 2293. (Star Trek VI: The Undiscovered Country) This chart was also seen in several Star Trek: The Next Generation and Star Trek: Deep Space Nine episodes set in the 24th century, from the year 2364 to 2370. These were: TNG: "Conspiracy", "The Measure Of A Man", "The Emissary", "The Mind's Eye", "The Game" and DS9: "In the Hands of the Prophets", "Cardassians".
This chart naming stars within 20 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. This chart would be seen in the episodes The Naked Now, The Last Outpost, Datalore, and Conspiracy.
The author and illustrator, Geoffrey Mandel, had this to say about the location of the Sol system in the Alpha Quadrant: Although the Sol system is located in the exact corner of the sector (and is 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. (Pg. 19)
The depiction of the Sol system in The Worlds of the Federation also included a tenth planet beyond Pluto.
The real-world debate on the status of Pluto as a planet was referenced in the novel Before Dishonor.