243 Ida is an asteroid located in the Asteroid Belt between Mars and Jupiter. Discovered in 1884 by astronomer Johann Palisa, it is approximately 15.7 kilometers (9.8 miles) in diameter. Ida is notable for having a small moon, named Dactyl, which orbits it. In 1993, the Galileo spacecraft became the first to study Ida up close, providing valuable data about its surface and composition. The images captured revealed that Ida has a rugged surface with craters and grooves, indicating a history of impacts. This mission helped scientists learn more about the formation and evolution of asteroids.