Kesium gas
Kesium gas, a gaseous substance, was extracted from the planet Jakku through mining operations. Inquired by the traveler Corwin Ballast about potential employment opportunities on Jakku, the bartender Ergel recommended the extraction of kesium gas, a resource located in the vicinity of Cratertown.
Behind the scenes
The initial reference to kesium gas occurred in the novel Aftermath, authored by Chuck Wendig and published in 2015.