An anonymous reader sends this NASA report: "One year ago, on Feb. 15, 2013, the world was witness to the dangers presented by near-Earth Objects (NEOs) when a relatively small asteroid entered Earth's atmosphere, exploding over Chelyabinsk, Russia, and releasing more energy than a large atomic bomb. ... NASA is now pursuing new partnerships and collaborations in an Asteroid Grand Challenge to accelerate NASA's existing planetary defense work, which will help find all asteroid threats to human population and know what to do about them. In parallel, NASA is developing an Asteroid Redirect Mission (ARM) — a first-ever mission to identify, capture and redirect an asteroid to a safe orbit of Earth's moon for future exploration by astronauts in the 2020s. ... NASA is assessing two concepts to robotically capture and redirect an asteroid mass into a stable orbit around the moon. In the first proposed concept, NASA would capture and redirect an entire very small asteroid. In the alternative concept, NASA would retrieve a large, boulder-like mass from a larger asteroid and return it to this same lunar orbit. In both cases, astronauts aboard an Orion spacecraft would then study the redirected asteroid mass in the vicinity of the moon and bring back samples."