Dynamics of Pluto and Charon

by: Dobrovolskis, A. R.

ABSTRACT

The dynamics of the Pluto-Charon system are reviewed from a historical
perspective. Although Pluto's orbit crosses Neptune's, an intricate system
of nested resonances keeps these planets apart. Pluto's orbit is apparently
chaotic as well. Pluto always keeps the same face turned toward Charon,
and vice versa. Tides also damp Charon's orbital eccentricity and inclina-
tion. Precession of Pluto's orbital plane causes Pluto's obliquity to vary
periodically from formally prograde to retrograde. Pluto is probably an
original member of the Solar system, but not an escaped satellite of Neptune.

Geophysical Research Letters, ISSN 0094-8276, vol. 16, Nov. 1989,
p. 1217-1220.