Asteroid Ida (HR)

This view of the asteroid 243 Ida is a mosaic of 5 image frames acquired by the Galileo spacecraft's solid-state imaging system at ranges of 3.057 to 3.821 Km on August 28, 1993, about 3-1/2 minutes before the spacecraft made its closest approach to the asteroid. Galileo flew about 2.400 Km from Ida at a relative velocity of 12.4 km/sec (28,000 mph). Asteroid and spacecraft were 441 million Km from the Sun. Ida is the second asteroid ever encountered by a spacecraft. It appears to be about 52 Km in length, more than twice as large as Gaspra, the first asteroid observed by Galileo in October 1991. Ida is an irregularly shaped asteroid placed by scientists in the S class (believed to be like stony or stony iron meteorites). It is a member of the Koronis family, presumed fragments left from the breakup of a precursor asteroid in a catastrophic collision. This view shows numerous craters, including many degraded craters larger than any seen on Gaspra.