Wikipedia:Today's featured article/June 5, 2017
The Jupiter trojans are a large group of asteroids that share the orbit of the planet Jupiter around the Sun. The first one discovered, 588 Achilles, was spotted in 1906 by German astronomer Max Wolf. By convention they are named after mythological figures from the Trojan War. Around 1 million of them are larger than 1 km in diameter. No firm evidence of any specific compound on their surface has been obtained, but it is thought that they are coated in tholins, organic polymers formed by the Sun's radiation. They are clustered in elongated, curved regions around Jupiter's two stable Lagrangian points: L4, lying 60° ahead of the planet in its orbit, and L5, 60° behind. Jupiter trojans are thought to have been drawn into their orbits during or before the migration of the giant planets. Mars and Neptune also have trojans, and the first Earth trojan was discovered in 2010. (Full article...)
Part of the Jupiter featured topic.