243 Ida

243 Ida (/?a?d?/) is an asteroid in the Koronis family of the asteroid belt. It was discovered on 29 September 1884 by Austrian astronomer Johann Palisa and named after a nymph from Greek mythology. Later telescopic observations categorized Ida as an S-type asteroid, the most numerous type in the inner asteroid belt. On 28 August 1993, Ida was visited by the unmanned Galileo spacecraft, while en route to Jupiter. It was the second asteroid visited by a spacecraft and the first found to have a natural satellite.