Asteroids are among the leftover debris from the solar system’s formation some 4.5 billion years ago
Collision in the asteroid belt between Mars and Jupiter 400 million years earlier triggered an ice age on Earth
Bennu asteroid, about the size of small mountain, is smallest object ever to be orbited by a human-made spacecraft
The close approach of the latest one to Earth came on Friday at a distance of about 64,000 km
Space probe is on its way to rendezvousing with a far away asteroid, in quest to study the origin of the solar system