SOLAR SYSTEM

Detailed explanation-1: -Comets are frozen leftovers from the formation of the solar system composed of dust, rock, and ices. They range from a few miles to tens of miles wide, but as they orbit closer to the Sun, they heat up and spew gases and dust into a glowing head that can be larger than a planet.

Detailed explanation-2: -The nucleus is the solid, central part of a comet, once termed a dirty snowball or an icy dirtball. A cometary nucleus is composed of rock, dust, and frozen gases.

Detailed explanation-3: -What is the difference? An asteroid is a rocky object that orbits the Sun. Asteroids are smaller than a planet, but they are larger than the pebble-size objects we call meteoroids. Comets are small icy dirtballs that orbit the Sun; comets are made of ice and dust while asteroids are made of rock).

Detailed explanation-4: -There are two primary sources for ice on Earth and our nearby neighbors: the planets themselves, and delivery by comets. As Earth, Venus, Mars, and Mercury evolved, they released gases from their interiors through volcanic activity.