Cladistical Analysis of the Jovian and Saturnian Satellite Systems

Abstract

Jupiter and Saturn each have complex systems of satellites and rings. These satellites can be classified into dynamical groups, implying similar formation scenarios. Recently, a larger number of additional irregular satellites have been discovered around both gas giants that have yet to be classified. The aim of this paper is to examine the relationships between the satellites and rings of the gas giants, using an analytical technique called cladistics. Cladistics is traditionally used to examine relationships between living organisms, the 'tree of life'. In this work, we perform the first cladistical study of objects in a planetary science context. Our method uses the orbital, physical and compositional characteristics of satellites to classify the objects in the Jovian and Saturnian systems. We find that the major relationships between the satellites in the two systems, such as families, as presented in previous studies, are broadly preserved. In addition, based on our analysis of the Jovian system, we identify a new retrograde irregular family, the Iocaste family, and suggest that the Phoebe family of the Saturnian system can be further divided into two subfamilies. We also propose that the Saturnian irregular families be renamed, to be consistent with the convention used in Jovian families. Using cladistics, we are also able to assign the new unclassified irregular satellites into families. Taken together, the results of this

Stability of Jovian Trojans and their collisional families

“…Elsewhere in the Solar system, other evolved populations contain dynamical families, the results of the collisional disruption of large parent bodies. Such collisional families have been identified in the asteroid main belt (see Hirayama 1918;Gradie et al 1979;Zappala et al 1984;Knežević & Milani 2003;Carruba et al 2013;Milani et al 2014;Nesvorný, Brož & Carruba 2015;Milani et al 2017), the Hilda (Brož & Vokrouhlický 2008) and Hungaria (Warner et al 2009;Milani et al 2010) populations, the irregular satellites of the giant planets (Grav et al 2003;Nesvorný et al 2003;Sheppard & Jewitt 2003;Nesvorný, Beaug & Dones 2004;Grav & Bauer 2007;Jewitt & Haghighipour 2007;Turrini, Marzari & Beust 2008;Turrini, Marzari & Tosi 2009;Bottke et al 2010;Holt et al 2018) and the Haumea family in the Edgeworth-Kuiper belt (Brown et al 2007;Levison et al 2008; de la Fuente Marcos & de la Fuente Marcos 2018). The traditional methodology for identifying these (Bus 2002;Grav et al 2012).…”

Phylogenetic Analyses of Quasars and Galaxies

“…For instance, similarity techniques (like most statistical clustering and classification or phenetic tools) tend to find hyperspheres in the parameter space, while phylogenetic tools are able to detect evolutionary paths as can be shown on stellar evolutionary tracks (Fraix-Burnet, 2016). Many applications have been published on many kinds of astrophysical objects (Fraix-Burnet et al, 2009, 2010, 2012Cardone and Fraix-Burnet, 2013;Fraix-Burnet and Davoust, 2015;Jofre et al, 2017;Holt et al, 2017).…”

Captured Small Solar System Bodies in the Ice Giant Region

“…After capture, both the Jovian and Saturnian Irregular satellites went through a sequence of collisions (Bottke et al 2010), that resulted in sets of families that can be seen today (Sheppard & Jewitt. 2003, Holt et al 2018). In the Jovian and Saturnian systems, each family can be represented by the largest fragment.…”

“…With regards to the Irregular satellites, collisional groups have also been discovered (Sheppard, & Jewitt. 2003, Holt et al 2018. Each group is represented by a large, type object (Holt et al 2018).…”