Caption: 
SwRI studied the only large binary known in the population of ancient bodies referred to as the Trojan asteroids, illustrated here, finding evidence for an early planetary shake-up in the solar system. The two swarms of Trojans orbit at roughly the same distance from the Sun as Jupiter, one swarm orbiting ahead of, and the other trailing, the gas giant. 

Credit: 
Image Courtesy of NASA/JPL-Caltech