 Ida is a distinctly elongated asteroid, with an irregular surface. Ida is 2.35 times as long as it is wide, and a "waist" separates it into two geologically dissimilar halves. This constricted shape is consistent with Ida being made of two large, solid components, with loose debris filling the gap between them. However, no such debris was seen in high-resolution images captured by Galileo. Although there are a few steep slopes tilting up to about 50°on Ida, the slope generally does not exceed 35 °. Ida's irregular shape is responsible for the asteroid's very uneven gravitational field. The surface acceleration is lowest at the extremities because of their high rotational speed. It is also low near the "waist" because the mass of the asteroid is concentrated in the two halves, away from this location.
