Orbital dynamics of Neptune Trojans

Abstract

Trojan asteroids share the same orbit with a planet, comprising together with the Sun and the planet an equilateral triangle in space. On the orbit of Jupiter, two clouds of thousands of asteroids named Greek Camp and Trojan Camp, by 60 degrees ahead and behind Jupiter respectively, have been well-known since as early as 1906. Trojan asteroids of Neptune however, was found quite late in the year of 2003. Nevertheless, evidences indicate that the Neptunes Trojan cloud is larger at least by one order of magnitude than the Jupiter Trojan cloud and the main asteroid belt, both in total number and in total mass, making itself the second largest reservoir of small bodies in the Solar system, only after the Kuiper belt. Meanwhile, the distinct orbits of Neptune Trojans that have been already observed, and the fact that they are a kind of connection between spaces within and beyond Neptune orbit, mean that they can serve as a touchstone of theories about the origin and evolution of the Solar system. We briefly present in this review the observations, the investigations on their orbital dynamics and the research on their origin.