High temperatures in the inner solar system made the difference. The many satellites of the Jovian planets changed the planet s atmosphere. Jovian planets are much larger than terrestrial planets. Its epicycle is so large that it carries the planet both closer and farther than Neptune from the Sun. Its orbit is more elliptical than the orbit of other planets.
Comets appear to come primarily from the direction of the constellation Hercules.
Comets are observed in all directions on the celestial sphere. Comets are best seen after midnight. Comets orbit the Sun in nearly circular orbits. Thus, you would want to study objects that had undergone the least amount of chemical change. The asteroid orbits are confined to the ecliptic.