Beside the nine large planets and their moons, space within our solar system and beyond it contains vast areas of emptiness, with a multitude of small objects and gas and dust particles in between.
A group of frozen comets, orbiting the Sun on various paths within the Oort Cloud, probably exists beyond Pluto. Their distinguishing feature is their long tail, which however, is only visible when the comet is in the point of its orbit closest to the Sun. In earlier times, comets were the subject of much superstition. The sudden and unexpected appearance of a bright light in the sky was seen as an omen of doom.
Shooting stars are another sudden light phenomenon, which everyone has probably seen. Shooting star is the common term used for a meteor. We see a shooting star when small pieces of cosmic matter, the debris from broken up comets, penetrate the Earth's atmosphere. Even pieces with a diameter of only a few centimetres cause the air around them to glow. Larger pieces of rock or iron meteorites can actually strike the Earth's surface and even sometimes create huge craters.
Between Mars and Jupiter there is an area where a swarm of minute asteroids and planetoids circle the Sun. It is called the asteroid_belt.
Between the planets, comets and other celestial objects there is interplanetary matter. It is made up mainly of minute particles of meteorites and particles of the solar wind.
