Unique fragment from Earth’s formation returns after billions of years in cold storage

Astronomers have found a unique object that appears to be made of inner solar system material from the time of Earth’s formation, billions of years ago. Observations show that C/2014 S3 (PANSTARRS) is the first object to be discovered on a long-period cometary orbit that has the characteristics of a pristine inner solar system asteroid. It may help understanding how the solar system formed.