Eadu (pronounced /ˈiːduː/) was a storm-stricken planet in the Outer Rim Territories. It hosted the Eadu Energy Conversion Laboratory prior to the outbreak of the Galactic Civil War, where Galen Erso and his team of scientists attempted to unlock the secrets of the kyber crystals as part of the Death Star project. The refinery was targeted by agents of the Alliance to Restore the Republic following the destruction of Jedha City and resulted in the ruination of the facility and the death of Erso.
Eadu was a remote, rugged, mountainous planet was located in the Eadu system of the Outer Rim Territories' Bheriz sector. It was solidly within Hutt Space along the Triellus Trade Route and lay on the edge of the known galaxy. The blue-hued world was shrouded in gloomy rainstorms, wind, and lightning strikes. The planet's cloud cover was so thick that it appeared to be a night world even in daytime, and clouds mired visibility while gales battered any starships attempting to reach the surface. It comprised difficult, rainswept terrain which afforded the planet natural defenses, although the southern hemisphere also contained an Eaduan village cluster populated by nerf herders. The ground was uneven and was made up of jagged rock formations, broad mesas, black stone ridges, and narrow spires. The rocky canyons bottomed out in dozens of writhing streambeds. The planet's rain had the smell of fecund soil with an undertone of acrid stink.
Eadu was little-known save for its rainfall and population of native nerf herders. During the Age of the Empire, Eadu was owned by Grand Moff Wilhuff Tarkin, and ceded to his eponymous Tarkin Initiative as part of the ongoing Death Star project begun prior to the onset of the Clone Wars. The Galactic Empire established a secret high energy conversion laboratory within the remote mountaintops of Eadu's northern hemisphere. This refinery, defended by the Eadu Flight Station, was administered by Sirro Argonne and guarded by stormtroopers of the 975th Battalion. Captain Magna Tolvan was responsible for security on Eadu. Director Orson Callan Krennic put Galen Walton Erso to work on unlocking the secrets of the kyber crystals within the secret installation. To this end, Erso led a team of scientists who conducted dynamic kyber field experiments south of their facility. The world was considered strategically insignificant due to communications blackouts, which made an analysis of the world difficult and was officially designated by the Empire for research and chemical processing. Individuals such as Cassian Jeron Andor considered it to be a sodden lump of a planet. However, the Empire created its final, functional superlaser on Eadu, and transported it to the Death Star to make the battle station fully operational.
In 1 BBY, Erso sent out pilot Bodhi Rook with a message for Saw Gerrera, informing him of a structural weakness in the Death Star. Krennic learned of the security leak and ventured to Eadu to deal with the Imperial traitor. At the same time, a team of Rebel agents led by Jyn Erso and Captain Cassian Jeron Andor arrived on Eadu with the intention of locating Erso. The mission became complicated after Krennic had Erso's fellow scientists shot in order to draw out a confession, and Rebel starfighters bombed the Eadu complex landing platform. This resulted in Galen's death and led Jyn's team on a further mission to steal the Death Star plans from Scarif. Because of the security breach, Tolvan was later sent to Yavin 4 following the destruction of the Death Star, as a punishment duty for the Eadu debacle.
Eadu had a relatively small planetary population estimated at two-point-five million, which included native Eaduans such as the nerf herders living in a village cluster in the southern hemisphere. These individuals were among the only features of Eadu known to the wider galaxy. It was the homeworld of Kris Elioup.