NASA’s Lucy mission, which is on an epic 6-billion-kilometre-long journey to study the Jupiter Trojan asteroids, has finally caught a glimpse of the asteroids.
Key points
- The Lucy spacecraft used its L’LORRI high-resolution camera to capture the first views of the Jupiter Trojan asteroids between March 25 and March 27.
- Lucy launched on an Atlas V rocket from the Cape Canaveral Space Force Station in Florida on October 26, 2021. About a year into its journey, after travelling around 620,000 kilometres, it captured stunning images of the Earth and the Moon, images that illustrate how far it had already travelled by that point.
- From March 25 to 27, 2023, Lucy used its highest resolution imager, L’LORRI, to capture its first views of four Jupiter Trojan asteroids: Eurybates, Polymele, Leucus, and Orus.
About Trojan asteroids
- Asteroids sharing an orbit with a planet, but which are located at the leading (L4) and trailing (L5) Lagrangian points, are known as Trojan asteroids.
- Although Trojan asteroids have been discovered for Mars (4 to date, 1 at L4 and 3 at L5) and Neptune (8 Trojans, 6 at L4 and 2 at L5) and even Earth (1 Trojan at L4), the term ‘Trojan asteroid’ generally refers to the asteroids accompanying Jupiter.
- There are currently over 4,800 known Trojan asteroids associated with Jupiter. About 65% of these belong to the leading group (L4) located 60o in front of Jupiter in its orbit, while the other 35% cluster around the L5 Lagrangian point and trail 60o behind Jupiter.
- The term ‘Trojan asteroid’ was coined when it was decided to name all asteroids discovered at the L4 and L5 points of Jupiter after warriors in the Trojan war, Greek and Trojan respectively.
- The exceptions are Hector (a Trojan spy in the Greek camp) and Patroclus (a Greek spy in the Trojan camp), the first two Trojan asteroids discovered and named before the two camps were established.
