On this day in 1991, NASA’s Galileo spacecraft conducted a flyby of asteroid Gaspra, an asteroid that orbits in the asteroid belt between Mars and Jupiter. The asteroid is about 10.5 miles long. Gaspra was discovered in 1916 by Russian astronomer G. N. Neujmin, who named it after a famous Russian spa retreat in Crimea.
The Galileo spacecraft’s primary mission was to visit Jupiter and its moons, but it also conducted other observations along the way, including flybys of asteroids Gaspra and Ida.
Here are a few facts about the Galileo mission from NASA:
- Galileo was the first spacecraft to orbit an outer planet.
- It was the first spacecraft to deploy an entry probe into an outer planet’s atmosphere.
- It completed the first flyby and imaging of an asteroid (Gaspra, and later, Ida).
- It made the first, and so far only, direct observation of a comet colliding with a planet’s atmosphere (Shoemaker-Levy 9).
- It was the first spacecraft to operate in a giant planet magnetosphere long enough to identify its global structure and to investigate its dynamics.
Our Awesome Universe 