What is the primary reason that astronomers suspect that some jovian moons were captured into their current orbits

The summary including its circumstances in question is outlined in the illustrating segment below.

Explanation:

An astronomer seems to be an astronomical specialist who performs his information about the research problem or area elsewhere in Earth's view.A few other moons include "backward" orbits (particularly in comparison to the movement or rotation of another planet), or are favorably committed to the equator of their continent.