Atmosphere

An atmosphere was a gaseous envelope surrounding planets, such as Earth.

Earths atmosphere being cleaned.

• Sol 3 had an atmosphere of 80% oxygen and 20% carbon dioxide
• The Doctor often checked that the planets he visited had a breathable atmosphere before leaving the TARDIS.
• Space had no atmosphere, so people would need to wear spacesuits when in outer space. (DW:Enlightenment)
• Sol 3 had a lot of toxins and dioxins in its atmosphere, which would have provided decent nutrition for the Nestene Conciousness. (DW: Rose)
• Sol 3's atmosphere had been contaminated after the fall of Satellite Five. (DW: Bad Wolf)
• New Earth had the same atmosphere as Sol 3, its predecessor. (DW: New Earth)
• The planet Malcassairo had an atmospheric shell. (DW:Utopia)
• The atmosphere of Sol 3 was temporarily opened to unleash an army of Toclafane. (DW:The Sound of Drums)
• The Tenth Sontaran Battle Fleet made Luke Rattigan develop the ATMOS in peoples cars, across the entire planet Earth, this was part of their plan to poison Earths atmosphere with clone feed, so Earth could become the new clone world for the Sontaran species, The Doctor later cleared the atmosphere, saving the planet. (DW: The Poison Sky)
• Sol 3's atmosphere was poisoned by the Sontarans and then cleared by the Torchwood Team in an alternate timeline. (DW:Turn Left)
• The Tenth Doctor needed a spacesuit as Mars had a poor atmosphere. (DW:The Waters of Mars.
• Alfava Metraxis had a breathable atmosphere. (DW: Time of Angels)