The NBC News article Mile-wide asteroid and its tiny moon to zoom past Earth this weekend; Dubbed 1999 KW4, the "binary" space rock will skim past our planet harmlessly at a distance of 3 million miles. shows the animated GIF below, and links to the Asteroid Tracker page 1999 KW4.
Images there are credited to
Dr. Steven Ostro et al. - http://echo.jpl.nasa.gov/~ostro/kw4/
but that link is dead. They also link to Wikimedia for sources
Without the link to Ostro et al (which Wikimedia also links to) there's no way to track this down.
How did scientists go from radar images to this very detailed GIF of two bodies orbiting each other, with such detail of the huge equatorial ridge on alpha?