In Star Wars: A New Hope, the Death Star destroys the planet Alderaan.
Alderaan is Princess Leia Organa’s homeworld and one of the galaxy’s best-known peaceful societies. The planet is portrayed as a blue-green, Earth-like world associated with diplomacy, culture, and opposition to the Galactic Empire. Leia’s adoptive father, Bail Organa, represents Alderaan in the Imperial Senate.
Grand Moff Tarkin orders Alderaan’s destruction after Leia refuses to reveal the location of the Rebel Alliance’s main base. She gives him the location of Dantooine, but Tarkin destroys Alderaan anyway, using the event as both a test of the Death Star’s superlaser and a warning to other worlds. The planet is annihilated in a single blast, killing its population and leaving only debris.
A common mix-up is confusing Alderaan with Endor or Tatooine. Tatooine is Luke Skywalker’s desert homeworld, while Endor is the forest moon where the second Death Star is attacked. Alderaan’s destruction is also distinct from the later destruction of the first Death Star, which Luke Skywalker helps bring about above Yavin 4.