Mars is the only terrestrial planet known to have long-term stable Trojan coorbitals. Recently, Christou (2013) and De la Fuente Marcos & De la Fuente Marcos (2013) have shown that several smaller Mars Trojans belong to a dynamical cluster centered on (5261) Eureka. While some of non-cluster Mars Trojans have colors distinct from Eureka (Rivkin et al. 2007), it is not clear if the cluster itself is compositionally homogeneous. Given that cluster member orbits should diverge over the age of the Solar System (Scholl et al. 2005), a recent origin of the cluster is likely. Our preliminary work indicates that the cluster could not have been formed through the slow dissipation of the Yarkovsky effect, in agreement with past results of Fleming & Hamilton (2000). Hence, our current expectation is that the cluster is collisional, and we expect to present an estimate of the age of the cluster at the meeting, based on long-term integrations of the cluster's dynamical diffusion. We will also discuss possible origin scenarios for Mars Trojans. It is now known that the Mars-crosser population was significantly larger in the past (Cuk 2012), and some Mars-crossers can spend time as temporary Trojans. Mechanisms of temporary Trojan stabilization include dynamical chaos and collisions (with some fragments of temporary Trojans becoming long-term stable). These and other routes will be tested using analytical arguments and numerical simulations. This work is supported by NASA PGG award NNX12AO41G.
AAS/Division for Planetary Sciences Meeting Abstracts #45
- Pub Date:
- October 2013