Atmospheric converter
From Tardis Wiki, the free Doctor Who reference
An atmospheric converter was a device used by the Tenth Doctor to clear the Earth's atmosphere of the ATMOS gas in 2009. It set fire to the atmosphere and dispersed the gas. The Doctor planned to use it to ignite the Sontaran flagship and kill the Sontarans onboard. Luke Rattigan took his place and blew up the Sontarans and their flagship along with himself and the atmospheric converter. The device functioned by emitting a blast that changed some of the atmosphere's compounds into oxygen. (TV: The Poison Sky [+]Loading...["The Poison Sky (TV story)"])