The story of Trojan asteroids

Trojan asteroids are asteroids that share an orbit with a planet and are located at the leading (L4) and trailing (L5) Lagrangian points of the planet’s orbit. Lagrangian points or Lagrange points are locations in space where the combined gravitational forces of two large bodies, such as the Earth and Sun, equals the centripetal force required for a small object to move with them. Thus, if a spacecraft is to be parked at this point, the fuel consumption required to keep it in place can be reduced. There are five Lagrangian points in total, of which three are unstable (L1, L2, L3) and two are stable (L4 and L5). L4 leads the orbit of the planet and L5 follows.