Light-year

A light-year was a unit of measurement used to measure interstellar distance. It was quantified as the distance that light travelled in a vacuum over the course of an Earth year. 100 light-years made up a light-century. (TV: The Ribos Operation)
== Known distances ==
=== From Earth ===
Planet XXX was 9.2 light years from Earth. (AUDIO: Through the Ruins)
Epsilon Eridani was "about 11 light-years or so" from Earth. (COMIC: Is Anyone There?)
Gliese 581d was 20 light-years from Earth. (TV: Smile)
Vega 3 was 27 light-years from Earth. (PROSE: K9 and the Beasts of Vega)
Arcturus was 40 light-years from Earth. (PROSE: Only a Matter of Time)
Aldebaran II was 68 light-years from Earth. (AUDIO: The Paradise of Death)
Halcyon was 90 light-years from Earth. (AUDIO: The Resurrection of Mars)
Sunday was 100 light-years from Earth. (PROSE: Wetworld)
Beta Caprisis was 100 light-years from Earth. (PROSE: Sanctuary)
In 1873, Mondas was 200 light-years from Earth. (AUDIO: The Silver Turk)
Lucifer was 280 light-years from Earth. (PROSE: Lucifer Rising)
Bellatrix was 324 light-years from Earth. (PROSE: Nightshade)
Gger was 500 light-years from Earth. (PROSE: Listen - The Stars)
Crimson Heart was 10,000 light-years from Earth. (TV: Death of the Doctor)
The Orpheus constellation was 10,000 light-years from Earth. (TV: Aeolian)
According to one account, Gallifrey was 30,000 light-years from Earth. (PROSE: The Devil Goblins from Neptune)
The homeworld of the Uvodni, located in the Spiral Cluster of the Dragon Nebula, was 34,000 light-years from Earth. (TV: Warriors of Kudlak)
New Earth was 50,000 light-years from Earth. (TV: Gridlock)
Vandos was 60,000 light-years from Earth. (COMIC: Mr Nobody)
Dæmos was 60,000 light-years from Earth. (TV: The Dæmons)
Galaxy Seven was 290,000 light-years from Earth. (PROSE: The Eyeless)
Surobos was 420,000 light-years from Earth. (COMIC: Shipwreck!)
Gorgos was 100,000,000 light-years from Earth. (TV: Eye of the Gorgon)
According to the Eighth Doctor, Gallifrey was 250,000,000 light-years from Earth. (TV: Doctor Who)
According to the Eleventh Doctor, Apalapucia was 2,000,000,000 light-years from Earth. (TV: The Girl Who Waited)
According to the First Doctor, Destination was billions of light-years away from Earth. (AUDIO: The Destination Wars)
=== From other locations ===
The Ao constellation and Qqaba were 9.6 light-years from Gallifrey. (PROSE: Lungbarrow)
Ribos was 300 light-years from the Magellanic Clouds. (TV: The Ribos Operation)
The Twelfth Cyber Legion was 20,000 light-years from Demons Run. (TV: A Good Man Goes to War)
Safeplace was about 32,000 light-years from Mars. (AUDIO: The Judgement of Isskar)
The First Doctor encountered a group of Watermen 5 million light-years from Q20. (COMIC: Dr. Who Meets the Watermen)
The Second Doctor once dematerialised the TARDIS while it was 4 quadrillion light-years from the nearest galaxy. (PROSE: When Starlight Grows Cold)
Katura was 3.62 light-years from Mars. (AUDIO: Judoon in Chains)
The blast on Hurala that destroyed the Exterminator during the Second Dalek War produced a flare visible from 7 light-years away. (PROSE: Prisoner of the Daleks)
== Known measurements ==
The Mutter's Spiral galaxy was around 100,000 light-years in diameter. (PROSE: The Eyeless) Before splitting apart into an armada of asteroid spacecraft, the home planet of the Sycorax was located in the wastelands of the galaxy, many light years away from Earth. (PROSE: )
The Morestran empire spanned 80,000,000 light-years. (PROSE: Zeta Major)
Category:Astronomy from the real world
Category:Units of distance from the real world
Category:Light
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