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A hydrocode model is applied to the data obtained from the Galileo space craft to determine the effects of collision on the asteroid 951 Gaspra. The model shows that impacts by large bodies may result in the formation of craters larger than those predicted earlier. The impacts will create considerable regolith and destruction of several smaller craters formed earlier by the collision of smaller objects.

The images of asteroid 951 Gaspra, taken by the Galileo space craft during October 1991, yield the shape model of the asteroid. The shape model reveals that Gaspra is an irregular astronomical body with an average radius of 6.1 kilometers. The rotation axis is aligned with the asteroid's moment of inertia as its mass distribution is uniform. Several flat regions, large and shallow concave crater-like areas characterize the surface of the asteroid.

Photometric studies of the images of asteroid 951 Gaspra, taken by the Galileo space craft during the October 1991 flyby, reveal the particle-phase function characteristics and microscopic texture of the asteroid. The texture and phase function characteristics are similar to those of other asteroids and the moon. The particle scattering albedo is 0.36 and the macroscopic surface roughness parameter is 29 degrees.

The grooves on the surface of asteroid 951 Gaspra are fractures modified by the inward drainage of regoliths with depths ranging from 30 to 200 meters. The regoliths are noncohesive substances of various sizes. The presence of grooves indicate that Gaspra was subjected to violent collisions with other astronomical objects.

Asteroid 951 Gaspara consists of craters with vague circular depressions and craters with sharp and well-formed features. The vague depressions are old craters and the ejecta around these craters are calorimetrically similar to the surrounding materials. The old craters are highly degraded and consist of low cohesive substances. The newly formed craters have a depth-diameter ratio of 0.14 and their ridges are calorimetrically different from the surrounding materials.

The north pole of asteroid 951 Gaspra was located by using a 19-point control network on the images obtained from the Galileo spacecraft during its October 1991 flyby. The right ascension is 9.5 degrees and declination is 26.7 degrees in the J2000 coordinates. The asteroid has a prograde rotation with a rotation period of 0. 2934197 days. The prime meridian passes through the crater, Charax.