A Uranus trojan is an asteroid that shares an orbit with Uranus and the Sun. Predicted in simulations earlier,[1] two trojans have been discovered in Uranus’s Lagrangian point L4 (leading Uranus).
(687170) 2011 QF99 was the first body to be classified as such a trojan in 2013, while in 2017 (636872) 2014 YX49 became the second.[2]
Several theories have come to be on how such trojans could orbit Uranus. Gravitational scattering is the most popular, stating that such asteroids (or comets) could have been gravitationally pulled by the other planets, leading them on a perfect trajectory towards Uranus, or somewhere where Uranus’s gravitational pull is neutral.
Designation | Cloud | Semimajor axis (AU) |
Perihelion (AU) |
Eccentricity | Inclination (°) |
(H) | Diameter (M) |
---|---|---|---|---|---|---|---|
(687170) 2011 QF99 | L4 | 19.167 | 15.765 | 0.177 | 10.796 | 9.6 | 60 |
(636872) 2014 YX49 | L4 | 19.113 | 13.762 | 0.279 | 25.524 | 8.79 | 77 |