Final answer:
Satellites are classified into regular, irregular, and captured categories, with different characteristics and orbital behavior. Regular satellites have circular, synchronous orbits, suggesting they formed alongside their planets. Irregular and captured satellites show a greater variety of properties and orbits, and are often thought to have been captured later.
Step-by-step explanation:
Satellite Classifications
Satellites of Jupiter and elsewhere in the solar system can be classified into three broad categories: regular satellites, irregular satellites, and captured satellites. Regular satellites have prograde orbits and are generally closer to the planet, indicating they likely formed from a circumplanetary disk. Irregular satellites often have retrograde orbits and are typically further from the planet, suggesting they were captured by the planet's gravity. Captured satellites are those that originally orbited the Sun but were pulled into orbit around a planet due to gravitational interactions.
Characteristics and Formation of Satellites
The regular satellites tend to have circular orbits and a synchronous rotation, meaning they keep the same face towards their planet, similar to Earth's Moon. These satellites may form in a process akin to the way the planets formed around the Sun. The irregular satellites, on the other hand, are thought to have been captured by the planet's gravity and therefore have highly elliptical and inclined orbits. Captured satellites exhibit varying characteristics depending on their original location and the capture process.
Satellites Around Jupiter
If Jupiter's satellite system were a mini solar system, the Galilean moons (Io, Europa, Ganymede, and Callisto) could be its "planets." Io and Europa exhibit characteristics more similar to terrestrial planets, with higher densities suggesting rocky compositions. Ganymede and Callisto could be likened to gas/ice giants due to their lower densities and compositions that include a greater proportion of ices.