243 Ida
Discovery and Naming
243 Ida was discovered on September 29, 1884, by Austrian astronomer Johann Palisa. The asteroid was named after a mythical nymph, Ida, who lived on the island of Crete in Greek mythology.
Physical Characteristics
243 Ida is an S-type asteroid, which means it is composed mainly of silicate (rocky) material. It has an irregular shape, with dimensions of approximately 59.8 kilometers by 25.4 kilometers by 18.6 kilometers. The surface of Ida is covered with numerous craters, the largest of which is named Asteroid crater.
Orbital Characteristics
243 Ida orbits the Sun in the Asteroid belt between Mars and Jupiter. It has an orbital period of 4.84 years and a rotation period of approximately 4.63 hours. The asteroid's orbit is slightly inclined compared to the plane of the Solar System, with an inclination of 1.13 degrees.
Exploration
243 Ida was visited by the Galileo spacecraft in 1993, which provided detailed images of the asteroid's surface. These images revealed that Ida has a small moon, later named Dactyl, making it the first asteroid discovered to have a natural satellite.
Significance
The discovery of Dactyl orbiting 243 Ida has provided valuable information about the formation and evolution of the Solar System. It has also led to a better understanding of the nature and composition of asteroids, which are considered to be remnants from the early Solar System.