Earth (Doctor Who)

The Earth, also known as Sol 3, plays a large part of the Doctor Who fictional universe for a majority of the stories in the series including it's spin-offs ever since the first serial in 1963, An Unearthly Child. The planet is one of the Doctor's most favourite planets as well where most of his companions and friends hail from. Apart from that, it's the planet where most aliens and villains choose to visit or invade which prompts the Doctor and his friends to help out in some way. The planet is also the twin to Mondas from which the Cybermen originate.

Key events in Earth's history
Apart from the numerous stories which take place in different parts of the planet, many events have involved the entire planet including in both the television series and it's spin-offs seen here in order of time:
 * In 4.6 billion BCE, the Earth is formed around the Racnos' ship core making it the core of the planet (The Runaway Bride).
 * The rock starts to form into a planet and oxygen is emitted onto the surface as well volcanoes start to form around the planet (Exploration Earth: The Time Machine)
 * 400 million BCE, Scaroth's spaceship explodes during take-off sparking the primordial ooze and starting life on the planet (City of Death).
 * The original dominant inhabitants of the planet the Silurians and Sea Devils go into hibernation in fear that the oncoming rock from space (later pulled into the planets gravitational field and became the Moon) would destroy the planet.
 * 65.5 million BCE, a giant freighter crashes into the Earth wipeing out the Dinosaurs (Earthshock).
 * 1939-1945, the second world war which all nations take arms in fighting (Just War).
 * 1963, the Earth is invaded by the Daleks altering Earth's history and wipeing out all humans with help of the "Eye of Time" but their actions are reverted by the Doctor and Earth's history is back to normal (City of the Daleks).
 * 2006, the Cybus Cybermen from the paralel universe invade the Earth via the void as friendly ghosts only to later reveal themselves and having to battel Daleks but later all pulled back into the void (Army of Ghosts/Doomsday).
 * 2009 Christmas Eve, the Master turns all humans on the planet into a copy of him but all return to normal after he is defeated.
 * 2164, the Daleks invade the Earth conquering all parts of the globe and using humans as slaves (The Dalek Invasion of Earth)
 * 200,100, Earth is invaded by a fleet of Daleks later all being wiped out by Rose after absorbing the Heart of the TARDIS (Bad Wolf/The Parting of the Ways).
 * The earth is engulfed in solar flares forcing the human race to seek refuge off-world (The Ark in Space, The Beast Below)
 * Year Five Billion, the Earth is destroyed by the Sun with the last of the race moved to other planets (The End of the World).

Geography
The terrain of the planet varies from different parts that including temperature. A majority of the planet is covered in oceans. Parts include deserts, forests and mountains plus various cities evolving over time.