Because Galileo was too far away for Gaspra's gravity to affect it, the spacecraft was not able to determine the asteroid's mass. On October 29, 1991, the Galileo spacecraft flew by the asteroid ...

On October 29, 1991, the Galileo spacecraft flew by the asteroid Gaspra on its way to Jupiter. ‘On This Day in Space’ Video Series on Space.com Gaspra was the first asteroid to ever be visited ...