On the Problem of Phoebe's Family

Details On the Problem of Phoebe's Family On the Problem of Phoebe's Family

Aug 2003

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2003dda....34.1003c&link_type=abstract

American Astronomical Society, DDA meeting #34, #10.03; Bulletin of the American Astronomical Society, Vol. 35, p.1044

Astronomy and Astrophysics

Astronomy

Scientific paper

With their large sizes, Himalia and Phoebe are distinguished among the irregular satellites of Jupiter and Saturn, respectively. Their orbital semimajor axes and eccentricities are similar as well; however, Phoebe follows an almost-ecliptical retrograde orbit, quite unlike that of prograde Himalia. Moreover, Himalia has a well-defined dynamical family, whereas Phoebe does not appear to, although several recently discovered irregular satellites of Saturn (2000 S1, S7, S9 and S12) have inclinations like Phoebe's (Gladman et al. 2001). These latter moons have significantly larger orbits than Phoebe's, with several not even crossing Phoebe's path, making a common origin problematic.
To ascertain whether any of the irregulars with orbits close to Phoebe's might be family members, we have run Monte-Carlo simulations that follow the loss and reaccretion of Phoebe-cratering ejecta. None of our runs could produce the presently observed distribution of small retrograde satellites of Saturn. This disagrees with the suggestion of Gladman et al. as to the nature of these small Saturnians. If Phoebe had ever been disrupted, these simulations imply that observable fragments should remain on close-by orbits that would not yet have been re-accreted owing to their long synodic periods with Phoebe. What might account for such different histories of similar-sized satellites? Possibly Phoebe was not disrupted whereas proto-Himalia was because orbital velocities are half as much in the former's neighborhood (cf. Nesvorn\' y et al. 2003). This is especially relevant since satellite-satellite collisions are much more likely than those with heliocentric impactors (Nesvorn\' y et al. 2003). Phoebe's population of craters, to be imaged during Cassini's close flyby on June 12, 2004, may be distinctive because of its collisional history.

Affiliated with

Also associated with

No associations

Rating

On the Problem of Phoebe's Family does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with On the Problem of Phoebe's Family, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and On the Problem of Phoebe's Family will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1667773