Comparative Planetary Science
The composition of the Eureka family of Martian Trojan asteroids
Apostolos Christou
Galin Borisov (Armagh Observatory), Stefano Bagnulo (Armagh Observatory)
Armagh Observatory
The so-called Martian Trojan asteroids orbit the Sun just inside the terrestrial planet region and are thought to date from the earliest period of the solar system’s history (Scholl et al, Icarus, 2005). Recently, Christou (Icarus, 2013) identified an orbital concentration of Trojans, named the “Eureka” cluster after its largest member, 5261 Eureka. This asteroid belongs to the rare olivine-rich A taxonomic class (Rivkin et al., Icarus, 2007; Lim et al., EPSC 2011). Unlike asteroids belonging to other taxonomies (e.g. C or S), no orbital concentrations or families of A-types exist. These asteroids may represent samples of the building blocks that came together to form Mars and the other terrestrial planets but have since been destroyed by collisions (Sanchez et al, Icarus, 2014, and references therein).
We have used the X-SHOOTER spectrograph on the VLT to obtain reflectance spectra of asteroids in the cluster and test their genetic relationship to Eureka. During the presentation we will show the spectra, compare them with available spectra for Eureka itself and discuss the implications for the origin of this cluster and for other olivine-dominated asteroids in the Main Belt.
13:30 - 15:00
EX - LT3 (320)