Each of our giant planets has a regular and an irregular systemof moons. Regular moons lie very close to the planet’s equatorial plane on nearly-circular direct orbits that share the planetary rotational sense, and likely formed in the disk. Irregular moons, in contrast, orbit at nearly all orbital inclinations (including retrograde) and often have very eccentric orbits; these properties alone lead one to believe that the regular moons were born in an accretion disk around each forming planet while the irregulars (or ancient precursors) were captured into orbit around the planet. I will review observational techniques by which we discover these moons, the current observational inventory and limits, what is suspected about the origin and evolution of the irregular moon systems we see today, and future prospects for learning more.
AB 107, Codyhall, 50 St. George Street Toronto
September 28, 2022
3:00pm - 4:00pm