The Galileo spacecraft was the first planetary mission to photograph an asteroid "up-close".  Its flyby of Gaspra occurred on 29 October 1991 at a distance of about 16,200 km. This picture of asteroid 951 Gaspra is a combination of the highest-resolution morphology and color information obtained by the Galileo spacecraft during its approach to the asteroid on October 29, 1991.  Gaspra is an irregular body with dimensions about 19 x 12 x11 kilometers (12 x 7.5 x 7 miles).

This montage of 11 images taken by the the Galileo spacecraft when it flew by the asteroid Gaspra on October 29, 1991, shows Gaspra growing progressively larger in the field of view of Galileo's solid-state imaging camera as the spacecraft approached the asteroid. Gaspra is roughly 17 kilometers (10 miles) long, 10 kilometers (6 miles) wide.  Gaspra spins once in roughly 7 hours, so these images capture almost one full rotation of the asteroid. Gaspra spins counterclockwise; its north pole is to the upper left, and the"nose" which points upward in the first image, is seen rotating back into shadow, emerging at lower left, and rotating to upper right.

The second of the two asteroids which Galileo encountered en route to Jupiter, Ida was discovered to have something different: its own satellite! Galileo's flyby of Ida (and its moon Dactyl) occurred on 28 August 1993 at a distance of about 2,400 km.  Ida is the second asteroid ever encountered by a spacecraft.  It appears to be about 52 kilometers (32 miles) in length,more than twice as large as Gaspra, the first asteroid observedby Galileo in October 1991.  Ida is an irregularly shaped asteroid placed by scientists in the S class (believed to belike stony or stony iron meteorites).   This view shows numerous craters, including many degraded craters larger than any seen on Gaspra.

This is the first full picture showing both asteroid 243 Ida and its newly discovered moon to be transmitted to Earth from the Galileo spacecraft--the first conclusive evidence that natural satellites of asteroids exist.  Ida's natural satellite is the small object to the right. .Ida is a heavily cratered, irregularly shaped asteroid in the main asteroid belt between Mars and Jupiter--the 243rd asteroid to be discovered since the first was found at the beginning of the 19th century. The small satellite is about 1.5 kilometers (1 mile) across in this view. Although appearing to be 'next' to Ida, the satellite is actually in the foreground, slightly closer to the spacecraft than Ida is. Combining this image with data from Galileo's near-infrared mapping spectrometer, the science team estimates that the satellite is about 100 kilometers (60 miles) away from the center of Ida.

This composite image shows the asteroid 243 Ida as seen from the Galileo spacecraft during its approach on August 28, 1993.  The images are arranged in chronological order from a time 3 hours 51 minutes before closest approach.  The six images show Ida at the same scale throughout. Ida's rotation axis is roughly vertical in these images, and the rotation causes the right-hand end of Ida to move toward the viewer as time progresses.  The features on Ida are less sharp in the earlier views because of the greater distances. Prominent in the middle three views is a deep depression across the short axis of the asteroid. This feature tends to support the idea that Ida may have originally been formed from two or more separate large objects that collided softly and stuck together. Also visible in the lower left view is an apparent linear albedo or reflectance boundary.

The Galileo imaging system captured this picture of the limb of the asteroid 243 Ida about 46 seconds after its closest approach on August 28, 1993, from a range of only 2480 kilometers.  This single frame successfully imaged a part of the sunlit side of Ida.   Prominent in this view is a 2 kilometer-deep'valley' seen in profile on the limb.

These images of the asteroid Toutatis were taken by radar from the Earth.  These are radar images of asteroid 4179 Toutatis made during the object's recent close approach to Earth.  The images reveal two irregularly shaped, cratered objects about 4 and 2.5 kilometers in average diameter which are probably in contact with each other. The four frames shown here were obtained on Dec. 8, 9, 10 and 13, 1992 when Toutatis was an average of about 4 million kilometers from Earth. The time required to obtain each of these images was 55, 14, 37 and 85 min. respectively. On each day, the asteroid was in a different orientation with respect to Earth.