Emily Lakdawalla talks about UnmannedSpaceflight.com, a place where everyday people explore the solar system by processing images from robotic spacecraft.
Dr. Amy Mainzer discusses how she and her team calculated how many asteroids are out in space, waiting to be discovered.
Dr. Barbara Cohen discusses craters on our moon, and how they will be explored by a new NASA mission called Lunar Flashlight.
Dr Paddack, one of the discoverers of the YORP effect, tells some funny stories from his time at NASA.