Solar system The solar system , was a star system centred on the star called Sol in the galaxy known as the Milky Way or Mutter ' s Spiral . History . The First Doctor was unfamiliar with the solar system prior to his departure on Gallifrey . However , his granddaughter Susan Foreman learned of its existence and that of Earth in her spatial cartography lessons . ( AUDIO : " The Beginning " ) During the time of the Silurian s and Sea Devil s , a rogue planet approached the orbit of their homeworld , Earth . The Third Doctor told the Silurians that instead of drawing off the Earth ' s atmosphere as their scientists had previously calculated , it became the Moon . ( TV : " Doctor Who and the Silurians " ) Mondas , which originally orbited the Sun at the same distance as Earth , was also affected by the rogue planet . ( COMIC : " The Prodigal Returns " ) When it arrived , Mondas left orbit and wandered out further into the solar system . ( TV : " The Tenth Planet " ) Circa 12 , 000 , 000 BC the Time Lord s placed Planet 5 in a time loop , in effect destroying it . The Fendahl , which came from the Fifth Planet and which the Time Lords had intended to destroy , may have destroyed life on Mars on its way to Earth . ( TV : " Image of the Fendahl " ) Stealing a prototype stellar manipulator , the Eleven concocted an ultimately unsuccessful plot to ignite Sol and destroy the solar system in 1639 . ( AUDIO : " The Satanic Mill " ) In the mid - 20th century , the human s of Earth s began to explore their solar system via probes and , tentatively at first , with manned missions . The Moon was the first object in the solar system to be visited by humans — at least , according to the official historical record . ( TV : " Blink " , et al ) Piloted by the Cybermen , Mondas returned to the solar system in 1986 . ( TV : " The Tenth Planet " ) Later , missions to Mars occurred . Accounts differed as to whether the first human landing on Mars was in the 20th century , ( TV : " The Ambassadors of Death " , etc ) or in 2041 or 2058 . ( TV : " The Waters of Mars " ) Circa 2009 , Earth was forcibly relocated to the Medusa Cascade by the Dalek s . ( TV : " The Stolen Earth " ) The relocation of Earth seemed to have no lasting effects on the solar system ; even Earth ' s Moon remained in place until the Tenth Doctor and his companion s returned Earth to its proper position . ( TV : " Journey ' s End " ) The end result of the incident was that the general populace of Earth were now aware of the existence of alien life ( TV : " " , et al ) , ushering in the planet ' s increased presence in interstellar affairs from the 21st century onward . ( TV : " The Christmas Invasion " , " Everything Changes " , et al ) In 2009 , the Time Lord homeworld , Gallifrey , briefly materialised near the planet Earth , before being returned to its proper location . ( TV : " The End of Time " ) Around 2089 , Susie Fontana Brooke , the granddaughter of Captain Adelaide Brooke piloted the first ever lightspeed ship from Earth to Proxima Centauri . Soon after that , the human race started colonising other star systems . ( TV : " The Waters of Mars " ) According to the Third Doctor , this happened after humans had " sacked " the solar system . ( TV : " The Mutants " ) The planetoid or moon Voga entered the solar system some time after the construction of the Nerva Beacon . ( TV : " Revenge of the Cybermen " ) In 2400 , the Dalek s launched a massive invasion of the solar system . ( COMIC : " Invasion of the Daleks " ) In the 30th century , a lurgy swept through the solar system . ( PROSE : " From Wildthyme with Love " ) Prior to 4000 , Mavic Chen assumed the position of Guardian of the Solar System . Chen ' s secret allies , the Daleks , at the same time proposed to conquer the solar system . ( TV : " Mission to the Unknown " , " The Daleks ' Master Plan " ) In 5000 , the Fourth Doctor destroyed Saturn ' s moon , Titan in order to destroy a colony of the Swarm . ( TV : " The Invisible Enemy " ) Circa 2 , 000 , 000 , the Time Lords transported the entire solar system using a magnetron . ( TV : " The Mysterious Planet " ) In the 57th segment of Time the last human s left on Earth evacuated the planet because of the increasing danger that it would fall into the Sun . They fled to planets such as Refusis II and Frontios . ( TV : " The Ark " , " Frontios " ) The now uninhabited Earth was preserved by the National Trust and over the billions of years following was restored to a ' classic Earth ' before it was finally destroyed by the expanding sun in the year 5 . 5 / Apple / 26 . ( TV : " The End of the World " ) Cultural significance . After a long struggle both on their own planet , Earth , and with other sentient species in the system , humans became the region ' s dominant species and led several different inter - planetary governments . ( TV : " The Daleks ' Master Plan " , " The Monster of Peladon " , " Bad Wolf " ) Indeed , the solar system ' s significance was largely tied to the fate of humanity , since humans became one of the universe ' s longest - lived species , continuing on until the universe itself was entering its final stage of development . ( TV : " The End of the World " , " Utopia " ) Behind the scenes . The term " solar system " can also be a simple synonym for star system in DWU fiction . However , in most instances , " solar system " — even though uncapitalised — refers to " the star system bound together by Sol " . The television story " The Waters of Mars " gives two contradictory figures for when humanity first landed on Mars . The first is when the Tenth Doctor refers to the colonists that founded the Bowie Base One colony in July 2058 as the " very first humans on Mars " , and the second is an on - screen obituary of Adelaide Brooke ( captain of the Bowie Base One colonists ) , which states she was part of a three - person team on Mars when she was 42 ( i . e . in 2041 ) . Neither of these points are especially reconcilable with " The Ambassadors of Death " . In the television story " Empress of Mars " , the Twelfth Doctor discovers a human expedition on Mars in the year 1881 , but was clearly unaware of them prior to the episode .