The camera was not sensitive enough to pick up its faint reflection. If you only glimpse your surroundings, you can't expect to reach your destination based on that information. The mission returned some infrared and spectral data on the asteroid but not all that was hoped for. Fifteen minutes after the encounter, the camera detected the asteroid, probably because it had a better reverse angle for reflecting sunlight, Rayman said. An instrument designed to detect ions near the asteroid detected none, said project scientist Robert Nelson, who compared the effort to smelling a bowling ball from 50 yards.
Most asteroids are just a jumble of minerals and rocks.
Asteroid scientist Ryan and Soderblom think Braille was knocked from Vesta but have yet to learn how the smaller rock came to have an orbit that approaches Earth while Vesta remains out in the asteroid belt between Mars and Jupiter. Images taken of Braille 13,000 to 14,000 km from the spacecraft were merged to reveal a fuzzy picture of the asteroid and engineers translated that image into a corkscrew shape. Collisions are a very common process in our solar system. This is like a giant laboratory impact model. Flight engineers turned on Deep Space 1's ion propulsion engine Friday to push it toward comet Wilson-Harrington, which it will fly by in January 2001, continuing on past comet Borrelly several months later.