The solar system includes the sun and anything that moves in an orbit around the sun, according to the National Aeronautics and Space Administration. This includes planets, moons, asteroids, meteoroids, comets and other objects with an orbit in space. The word solar refers to the sun, which is at the center of the solar system.
Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune are the eight planets that orbit in the solar system, according to the Space Telescope Science Institute. Each planet has one or more moons that also have an orbit around the sun while in the accompanying planet’s gravitational pull. Pluto is a dwarf planet, notes National Geographic. All of the elements in the solar system are in the sun’s gravitational pull, which keeps everything in its specific orbit. The solar system has no physical boundaries, so the exact size of the solar system can't be determined. However, the sun is 93 million miles away from Earth.
The solar system was formed from debris that remained after the development of the sun, according to Space Telescope Science Institute. Rotation mixed with gas, dust and other particles to form the planets, moons and other elements. The debris remained in the sun’s orbit to create the solar system. Scientists estimate that the solar system is almost 5 billion years old.