Three new stable L5 Mars Trojans

TL;DR

This paper identifies three new stable L5 Mars Trojans, analyzes their long-term stability, and discusses their possible origin from a larger disrupted body, contributing to understanding Mars's Trojan population and Solar system history.

Contribution

It reports the discovery of three additional stable L5 Mars Trojans and analyzes their dynamical stability and potential collisional origin, expanding knowledge of Mars's Trojan population.

Findings

2011 SC191, 2011 SL25, 2011 UN63 are stable L5 Mars Trojans.

These Trojans may have been stable over the age of the Solar system.

A collisional disruption of a larger body could explain the asymmetry in Trojan populations.

Abstract

Mars was second to Jupiter in being recognized as the host of a population of Trojan minor bodies. Since 1990, five asteroids - 5261 Eureka, (101429) 1998 VF31, (121514) 1999 UJ7, 2001 DH47 and (311999) 2007 NS2 - have been identified as Mars Trojans, one L4 and four L5. Dynamical and spectroscopic evidence suggests that some Mars Trojans may be remnants of the original planetesimal population that formed in the terrestrial planets region. Here we revisit the long-term dynamical evolution of the previously known Mars Trojans and show that 2011 SC191, 2011 SL25 and 2011 UN63 are also trailing (L5) Mars Trojans. They appear to be as stable as Eureka and may have been Trojans over the age of the Solar system. The fact that five Trojans move in similar orbits and one of them is a binary may point to the disruption of a larger body early in the history of the Solar system. Such a catastrophic event may also explain the apparently strong asymmetry in terms of number of objects (one versus seven) between the L4 and L5 regions. Future spectroscopic observations should be able to reject or confirm a putative common chemical signature that may lend further support to collisional scenario.