Objects in the solar system

 Dwarf planets are celestial bodies that orbit the Sun and are large enough to be round, but they have not cleared other objects from their orbit like regular planets have. One of the most famous dwarf planets is Pluto, which was once considered the ninth planet in the solar system. Other dwarf planets include Eris, Haumea, and Ceres. These objects help scientists learn more about the outer regions and history of the solar system.

Moons are natural objects that orbit planets and other bodies in the solar system. Different planets have different numbers of moons—Earth has one moon, while Jupiter and Saturn have dozens. Moons can be rocky, icy, or a mixture of both, and some even have atmospheres. Scientists believe certain moons, such as Europa and Enceladus, may have oceans beneath their icy surfaces that could possibly support life.

Comets are small icy objects that travel through the solar system in long, curved orbits around the Sun. They are often called “dirty snowballs” because they are made of ice, dust, and rocky material. When a comet gets close to the Sun, the heat causes its ice to turn into gas, creating a glowing cloud called a coma and a long tail that can stretch for millions of kilometers. The tail always points away from the Sun because of solar wind and radiation. Famous comets, such as Halley's Comet, can be seen from Earth during certain periods of time.

Asteroids are rocky objects that orbit the Sun and are smaller than planets. Most asteroids are found in the asteroid belt located between Mars and Jupiter. They come in many shapes and sizes, from tiny rocks to objects hundreds of kilometers wide. Scientists study asteroids because they contain materials left over from the early solar system. Some asteroids occasionally pass close to Earth, and space agencies carefully track them to make sure they do not pose a danger.

Meteors are bright streaks of light that appear in the sky when small pieces of rock or metal from space enter Earth’s atmosphere at high speed. These space rocks, called meteoroids, heat up because of friction with the air and glow as they travel across the sky. Meteors are often called “shooting stars,” even though they are not actually stars. Most meteors burn up completely before reaching the ground, but larger ones can survive and land on Earth as meteorites. Meteor showers happen when Earth passes through trails of dust and debris left behind by comets, causing many meteors to appear in the sky at once.