243 Ida is an asteroid in the Koronis family of the asteroid belt. It was discovered on 29 September 1884 by Austrian astronomer Johann Palisa at Vienna Observatory and named after a nymph from Greek mythology .

Nov 3, 2024 · Ida is the second asteroid visited by a spacecraft, and the first found to have its own moon. The moon was later named Dactyl. On Aug. 28, 1993, NASA's Galileo spacecraft flew by Ida at a distance of about 1,500 miles (about 2,400 kilometers) en route to Jupiter.

Dactyl (/ ˈ d æ k t ɪ l / DAK-til; formally (243) Ida I Dactyl) is a small asteroid moon 1,200 by 1,400 by 1,600 m (3,900 by 4,600 by 5,200 ft), in size) that orbits 243 Ida, a main-belt asteroid.

Feb 1, 1996 · This is the first full picture showing both asteroid 243 Ida and its newly discovered moon to be transmitted to Earth from the National Aeronautics and Space Administration's (NASA's) Galileo spacecraft--the first conclusive evidence that natural satellites of asteroids exist.

Aug 28, 1993 · Dactyl is the first natural satellite of an asteroid ever discovered and photographed. The tiny moon is about 1.2 by 1.4 by 1.6 km (0.75 by 0.87 by 1 mile) across. The name is derived from the Dactyli, a group of mythological beings who lived on Mount Ida.

Mar 23, 1994 · The first-ever photograph of a moon of an asteroid, sent to Earth by NASA's Galileo spacecraft, was released by the space agency today. The photo, of asteroid 243 Ida and its newly discovered natural satellite, was taken by …

Explanation: This asteroid has a moon. The robot spacecraft Galileo on route to Jupiter in 1993 encountered and photographed two asteroids during its long interplanetary voyage. The second minor planet it photographed, 243 Ida, was unexpectedly discovered to have a moon.

Ida and Dactyl: Asteroid and Moon Credit: Galileo Project, JPL, NASA. Explanation: This asteroid has a moon! The robot spacecraft Galileo destined to explore the Jovian system, encountered and photographed two asteroids during its long interplanetary voyage to Jupiter.

The second asteroid it photographed, called Ida, was discovered to have a moon which appears as a small dot to the right of Ida in this picture. The tiny moon, named Dactyl, is about one mile across, while the potato shaped Ida measures about 36 miles long and 14 miles wide.

Mar 12, 2025 · During its flyby on August 28, 1993, Galileo captured detailed images of the asteroid Ida from a distance of 2,400 kilometers, revealing it to be an S-type asteroid with an unexpected companion moon later named Dactyl.