A probe intended to study the Trojan asteroids takes off

THE STORY of the Trojan war, as told by Homer and related down the centuries, is one of intrigue and heroes. And, as is the way of characters from Greek mythology, the names of many of those involved have ended up attached to objects in the sky.In the early 20th century astronomical photography showed that Jupiter, the solar system’s largest planet, was accompanied not only by its moons, but also by more distant acolytes. These were clusters of asteroids that followed the giant planet’s orbit precisely, but either led or trailed Jupiter itself by about 60° of arc.