5261 Eureka

June 20, 1990 and turned out to be the first known Mars Trojan asteroid. It trails Mars (at the L₅ point) at a distance varying by only 0.3 AU during each revolution (with a secular trend superimposed, changing the distance from 1.5-1.8 AU around 1850 to 1.3-1.6 AU around 2400). Minimum distances from the Earth, Venus and Jupiter are 0.5, 0.8 and 3.5 AU, respectively.

Long-term numerical integration shows that the orbit is stable. Kimmo A. Innanen and Seppo Mikkola note that "contrary to intuition, there is clear empirical evidence for the stability of motion around the L₄ and L₅ points of all the terrestrial planets over a timeframe of several million years".

Since then, other Mars Trojans have been identified; namely 1999 UJ₇ at the L₄ point and 1998 VF₃₁, 2001 DH₄₇, 2001 FG₂₄, and 2001 FR₁₂₇ at the L₅ point. The co-orbitals 1998 QH₅₆ and Previous asteroid | 5261 Eureka | The Minor Planets |- | align="center" style="font-size: 90%;" | Vulcanoids | Main belt | Groups and Families | Near-Earth objects | Jupiter Trojans |- | align="center" style="font-size: 90%;" | Centaurs | Trans-Neptunians | Damocloids | Comets | Kuiper Belt | Oort Cloud |- | align="center" style="font-size: 90%;" | (For other objects and regions, see: Binary asteroids, Asteroid moons and the Solar system) |- | align="center" style="font-size: 90%;" | (For a complete listing, see: List of asteroids) |}