Ida

Definition

Ida is an asteroid in the Koronis family located in the main asteroid belt between Mars and Jupiter. It is notable for having its own moon, Dactyl.

5 Must Know Facts For Your Next Test

1. Ida was discovered on September 29, 1884, by Austrian astronomer Johann Palisa.
2. Ida's moon, Dactyl, was discovered by the Galileo spacecraft in 1993.
3. Ida is composed mainly of silicate rock and has a heavily cratered surface.
4. The diameter of Ida is approximately 31.4 kilometers (19.5 miles).
5. Ida's orbit lies within the main asteroid belt at an average distance of about 2.86 AU from the Sun.

Review Questions

• Who discovered asteroid Ida and when?
• What spacecraft discovered Ida's moon Dactyl?
• What is the primary composition of Ida?

Related terms

Dactyl: A small moon that orbits asteroid Ida, discovered by the Galileo spacecraft in 1993.

Main Asteroid Belt: The region of space located between the orbits of Mars and Jupiter where most asteroids are found.

Koronis Family: A group of asteroids that share similar orbital elements and are believed to have originated from a common parent body.