This  and the following 10 images were taken by the Galileo as it flew by the asteroid
     Gaspra on October 29, 1991. They show Gaspra growing progressively larger in the field
     of view of Galileo's solid-state imaging camera as the spacecraft approached the
     asteroid. Sunlight is coming from the right. Gaspra is roughly 17 kilometers (10 miles)
     long, 10 kilometers (6 miles) wide. The earliest view (upper left) was taken 5 3/4
     hours before closest approach when the spacecraft was 164,000 kilometers (102,000
     miles) from Gaspra, the last (lower right)at a range of 16,000 kilometers (10,000
     miles), 30 minutes before closest approach. 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. Several craters are visible on the newly seen sides of
     Gaspra, but none approaches the scale of the asteroid's radius. Evidently, Gaspra
     lacks the large craters common on the surfaces of many planetary satellites,
     consistent with Gaspra's comparatively recent origin from the collisional breakup of a
     larger body. The Galileo project, whose primary mission is the exploration of the
     Jupiter system in 1995-97, is managed for NASA's Office of Space Science and
     Applications by the Jet Propulsion Laboratory.