Polis Massa Base was a research base set up by the Archaeological Research Council on Polis Massa, a barren planetoid in the middle of asteroid field. The base included mining operations and a medical center. When Darth Sidious ordered the extermination of all Jedi, Senator Bail Organa of Alderaan spirited Yoda, Grand Master of the Jedi Order, off Coruscant to the Polis Massa Base. Shortly thereafter, Jedi Master Obi-Wan Kenobi brought the stricken and pregnant Senator Padmé Amidala to the base's medical bay. Having lost the will to live due to the betrayal of her husband, Amidala was dying, but she managed to give birth to her twins Luke and Leia before breathing her last.