A search for L4 Trojan asteroids of Mars

We propose to use the Mosaic camera with the KPNO 0.9-meter telescope to carry out a search for L4 Trojan (1:1 resonant) asteroids of Mars. Theoretical studies have shown that Mars Trojans may be primordial objects. However, because the locations of dynamical stability for these faint objects correspond to high-inclination orbits, deep ecliptic surveys (e.g., Spacewatch) and shallower all-sky surveys (LINEAR) are both unlikely to discover Mars Trojans. Based on theoretical predictions, we might discover 5-10 new Trojan asteroids in the ~250 deg^2 we will survey in this program, and our primary science goal will be to derive empirical sky densities and therefore the total number of L4 Mars Trojans larger than 500 meters diameter. However, we found zero new L5 Mars Trojans in our similar 2005A experiment. Interpretation is under way, but this apparent lack of Mars Trojans may indicate that removal mechanisms (e.g., Yarkovsky effect) are more effective than previously thought. We will search for L4 Mars Trojans in 2006A to confirm our null result and constrain the deficit of Mars Trojans (or else discover new Mars Trojans and compare the L4 and L5 populations and sky densities). Constraining the population of Mars Trojans will aid our understanding of the Solar System's small bodies, long-term dynamical stability, and potentially the conditions prevailing during planet formation.