Mutter's Spiral

"Mutter's Spiral" is the Time Lord designation for the galaxy in which the Sol system is located. Humans know Mutter's Spiral as the Milky Way or as Adric referred to it, Galaxia Kuklos.

Mutter's Spiral is approximately 100,000 light-years in diameter, with the Sol System positioned approximately 27,000 light-years from the center. Together with Andromeda, Magella Minor, and other galaxies, Mutter's Spiral comprises the Local Group. Most of the planets visited by the Doctor in his travels have been, or appear to be, in this galaxy.

Planets and other locales located within Mutter's Spiral
The following planets have either been visited by the Doctor and/or his companions, or have been mentioned in the various Doctor Who stories. They are either definitely located within Mutter's Spiral, or may be inferred to be:

The Sol System

 * Cassius
 * Earth (a.k.a. Sol III, Ravalox)
 * Fendhal homeworld (a.k.a. the Fifth Planet)
 * Iapetus
 * Jupiter
 * Mars
 * Mondas
 * the Moon
 * Neptune
 * Pluto
 * Titan
 * Uranus
 * Venus
 * Victoria
 * Voga
 * Vulcan

Other planetary systems
Alpha Centauri; Arcturus; Argolis; Avalon; Azure; Bukol; Cait; Capella; Calderon IV; Calufrax; Chameleon homeworld; D&; Darkheart; Delta Magna; Desperus; Deva Loka; Dido; Diplos in the Tau Ceti system; Draconia; Eden; Exxilon; The Eye of Orion; Foamasi homeworld; Frontios; Hakol; Jagaroth homeworld; Jenggel; Kastopheria; Kastria;  Kembel; Krynoid homeworld; Macra homeworld; Mandragora Helix; Manussa; Mechanus; Mimosa II; Mongo; Ogron homeworld; Ogros in the Tau Ceti system; Oseidon; Peladon; Pesca; Phaester Osiris; Raaga; Refusis II; Ruta III; Rigel;  Sarn; Schirr homeworld; Sirius IV; Solos; Spiridon; Tara; Tarron; Telos; Terileptil homeworld; Tigella; Trion; Uxarieus; Vedela; Vega Nexos; Vorella; Xeraphas; Xoanon's world; Yemaya; Zanak; Zolfa-Thura; Zygon homeworld