EPSC Abstracts
Vol. 18, EPSC-DPS2025-668, 2025, updated on 09 Jul 2025
https://doi.org/10.5194/epsc-dps2025-668
EPSC-DPS Joint Meeting 2025
© Author(s) 2025. This work is distributed under the Creative Commons Attribution 4.0 License.
Evidence for cascade disruption and for collisions among the Martian Trojans
1,5,1,5,7- 1Armagh Observatory and Planetarium, Armagh, Northern Ireland, UK (apostolos.christou@armagh.ac.uk)
- 2Department of Astronomy, University of Florida Gainesville, Gainesville, FL, USA
- 3Division of Science, New York University Abu Dhabi, Abu Dhabi, UAE
- 4Center for Astro, Particle and Planetary Physics (CAP3), New York University Abu Dhabi, UAE
- 5Department of Physics and Astronomy, Queen’s University Belfast, Belfast, Northern Ireland, UK
- 6SETI Institute, Mountain View, CA, USA
- 7INAF, Osservatorio Astrofisico di Arcetri, Firenze, Italy
As the nearest stable repository of asteroids to both the Earth and the Sun, the Mars Trojans (MTs) represent a unique natural laboratory to study the outcomes of small asteroid evolution over Gyrs [1]. Their small sizes notwithstanding, MTs exhibit some unique features: a strong asymmetry favouring L5 vs L4 residents [2,3]; a family of L5 asteroids that are likely products of YORP-induced rotational spin-up and breakup [4,5] from (5261) Eureka; and the olivine-dominated composition of this family [6,7], one of only two known to exist [8].
Ongoing asteroids surveys continue to discover new members of this population and the upcoming Rubin Legacy Survey of Space and Time (LSST; [9]) will likely increase their number several-fold. In anticipation of the LSST discoveries, we take a fresh look at MTs using a larger sample of asteroids than was available in earlier works. Details of our study can be found in [10]. Our statistical analysis of the new sample reveals the existence of two additional clusters of three (3) asteroids apiece with >95% statistical confidence. One of the clusters is embedded within the Eureka family and is probably the result of ongoing cascade disruption among family asteroids [11]. The second group is characterised by a high libration amplitude, not easy to reconcile with YORP fission from Eureka and its family. We argue instead that this group represents impact ejecta from a collision that occurred during the ~1 Gyr age of this family. This is the first positive evidence that collisions play a role in the Gyr evolution of these small asteroids, alongside solar-thermal effects.
References
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How to cite: Christou, A., Georgakarakos, N., Marshall-Lee, A., Humpage, A., Cuk, M., and Dell'Oro, A.: Evidence for cascade disruption and for collisions among the Martian Trojans, EPSC-DPS Joint Meeting 2025, Helsinki, Finland, 7–12 Sep 2025, EPSC-DPS2025-668, https://doi.org/10.5194/epsc-dps2025-668, 2025.
