Why have scientists and engineers invested so much time, effort and money into a mission to a nearby asteroid?

Why have scientists and engineers invested so much time, effort and money into a mission to a nearby asteroid?
NASA’s OSIRIS-REx spacecraft has uncovered some interesting details about the asteroid’s eruptive particle plumes, jagged surface and more
NASA’s OSIRIS-REx spacecraft has already spotted the signs for water residing in the asteroid’s surface
The next New Frontier mission has been narrowed down to two final concepts
The team behind the Rosetta mission report exclusively for All About Space on how the comet chaser has solved the mystery of the Solar System
The asteroid sample return mission will blast off from Cape Canaveral between 00:05 and 02:05 (BST) on Friday 9 September
OSIRIS-REx will launch for asteroid Bennu in early September
We present the evidence for why we’re living in a multiverse in the latest issue of All About Space