Saturn

Saturn (or Sol VI) was the sixth planet of the Sol system. It was named by humans after the Roman god of agriculture. (TV: The Invisible Enemy)

Astronomical data
Saturn was a gas giant, several million times larger than Earth. There were permanent depressions and lightning storms at both poles. Saturn had rings made of fragments of ice, which ranged in size from pebbles to ice the size of houses. The rings were made of a moon that was destroyed by the Arkive roughly around 50 million B.C. (PROSE: The Wheel of Ice)

Reptilian creatures — "the Saturnian monsters" — lived on the moon. (COMIC: Invasion of the Daleks)

History
The Perseus Corporeal had settlement on the moons of Saturn. (PROSE: The Ethereal)

In the 21st century, Saturn was chosen over Jupiter as the first gas giant to be harvested from. Bootstrap, Inc. sent colonists to Mnemosyne to harvest bernalium and Titan to harvest methane. (PROSE: The Wheel of Ice)

At some point after the 21st century, gardens were grown in the clouds of Saturn. (PROSE: The Wheel of Ice)

When asked about her holiday experiences, Donna Noble listed the rings of Saturn among the locations which she had visited. (COMIC: The Widow's Curse)

Rudy Zoom claimed he was the first man to cycle the rings of Saturn. (COMIC: The Eye of Torment)

In 2400, the Daleks invaded the solar system. Saturn's moons were the second target and the Saturnian monsters were wiped out. (Humans were not present.) (COMIC: Invasion of the Daleks)

In the 25th century, one of the stops for the Interplanetary Air Race was Saturn. (PROSE: The Five-Leaf Clover)

In the 26th century, cities like Chelsea 426 floated in the clouds of Saturn. (PROSE: The Taking of Chelsea 426)

In the 30th century, the palace of the Divine Empress orbited Saturn. (PROSE: Original Sin)

In the 30th century, Saturn's moon Japetus was part of the Earth Empire. (PROSE: So Vile a Sin)

In the 42nd century, Saturn was conquered by the Dalek Empire. (AUDIO: "Death to the Daleks!")

The Fifth Doctor and Nyssa visited Saturn in the future when there was a human colony on the planet; however, there was no explanation of how the atmosphere and surface were stabilised or how the gravity was regulated. The Doctor had heard of a utopian society on Saturn in the 47th century, but had never gotten round to visiting it before.

The utopian society had several interesting aspects. When citizens reached the age of one hundred years, they were forced to retire to Titan, where they ended up doing menial jobs and remotely operating all the public services and amenities on Saturn. Every automated system on Saturn, right down to the doors, was operated by thumbprint: these thumbprints automatically cut out when the owner reached one hundred. Robot servants were used on Saturn for jobs such as waiting on tables. Babies were created in vitro and delivered to their parents on Saturn when they reached the age of twenty years (therefore, there were no children nor teenagers on Saturn). Only people with satisfactory genetic stock were allowed to reproduce. (PROSE: Saturn)

Saturn was visible through the windows of a spaceship transporting Daleks and Voords through the solar system. (PROSE: Doctor Who and the Daleks)