The Big One was a large comet that was located within the Cularin comet cloud, in the Cularin system. During the time of the Clone Wars, the Comet Broom Service attempted to send the comet into the orbit of the planet Almas, as part of the Cometary Water Reclamation Project, an operation that had been commissioned by the Dark Jedi Garth Ezzar. Ezzar sabotaged the project in an attempt to discredit the Jedi Order, by framing Jedi Master Lanius Qel-Bertuk as being involved in the operation and making it appear that the Jedi wanted to crash the comet into the Almas Sith fortress on the surface of the planet, thereby putting the planet's inhabitants at risk. However, the Heroes of Cularin thwarted the plot and prevented the Big One from crashing into Almas.