SOLAR SYSTEM

Detailed explanation-1: -Answer: Comets are believed to have two sources. Long-period comets (those which take more than 200 years to complete an orbit around the Sun) originate from the Oort Cloud. Short-period comets (those which take less than 200 years to complete an orbit around the Sun) originate from the Kuiper Belt.

Detailed explanation-2: -Researchers have found that some near-Earth asteroids are actually burned-out comets, and most of them would have started out in the Kuiper Belt. (The other source of comets is the Oort Cloud, where most long-period comets on highly tilted orbits originate.)

Detailed explanation-3: -Most comets originate in the Oort cloud or in the Kuiper belt. Other bodies’ gravity can alter their orbits, causing them to pass close to the Sun. Short-period comets return in 200 years or less, others in thousands of years or not at all.