The Galileo spacecraft, launched by NASA in 1989, set out on a mission to explore Jupiter and its moons. As part of its journey to reach this distant planet, Galileo conducted a flyby of asteroid 951 Gaspra on October 29, 1991. This flyby was remarkable, as it represented the first time a spacecraft had encountered an asteroid, opening a new chapter in planetary exploration. Galileo traveled approximately 16 kilometers from the asteroid, allowing it to capture high-resolution images and gather scientific data, which included measurements of Gaspra’s shape, surface features, and composition.

Gaspra, located in the main asteroid belt between Mars and Jupiter, revealed a potato-like shape, with a surface covered in craters and grooves. The spacecraft's equipment was designed to analyze the asteroid's mineral composition, shedding light on the materials that formed the early solar system. The data collected during this encounter helped scientists understand the processes that governed asteroid formation and evolution over billions of years.

The significance of the Galileo mission extended beyond asteroids, as the information gathered contributed to subsequent missions, influencing the design and objectives of later asteroid exploration efforts. This successful flyby demonstrated the feasibility of encountering and studying small celestial bodies, ultimately paving the way for future missions such as the NEAR Shoemaker and Osiris-Rex, which focused specifically on asteroids.