  Mars is the only terrestrial planet known to have Tro jan (co-orbiting)
asteroids, with a confirmed population of at least 4 objects. The origin of
these objects is not known; while several have orbits that are stable on
solar-system timescales, work by Rivkin et al. (2003) showed they have
compositions that suggest separate origins from one another. We have obtained
infrared (0.8-2.5 micron) spectroscopy of the two largest L5 Mars Tro jans, and
confirm and extend the results of Rivkin et al. (2003). We suggest that the
differentiated angrite meteorites are good spectral analogs for 5261 Eureka,
the largest Mars Trojan. Meteorite analogs for 101429 1998 VF31 are more varied
and include primitive achondrites and mesosiderites.

Astrophysics