SOLAR SYSTEM

Detailed explanation-1: -Comets are generally classified into three orbital types according to their periods: namely, the long-period comets with p > 200 years; the intermediate-period comets with P between 20 and 200 years; and finally, the short-period comets with P < 20 years.

Detailed explanation-2: -Stony meteorites are made of rock, sometimes small bits of iron, and are formed from the outer crust of an asteroid or planet. They can look very similar to Earth rocks, so it takes expert eyes to find them!

Detailed explanation-3: -Robotic Exploration. NASA’s robotic spacecraft allow us to visit comets, asteroids, and dwarf planets up close, and even bring back samples to study. We are just beginning to figure out what these places are like, what they are made of, and how they formed.

Detailed explanation-4: -Some exist in a wide disk beyond the orbit of Neptune called the Kuiper Belt. We call these short-period comets. They take less than 200 years to orbit the Sun. Other comets live in the Oort Cloud, the sphere-shaped, outer edge of the solar system that is about 50 times farther away from the Sun than the Kuiper Belt.