asteroids-chunks of rock and metal in orbit around the Sun.

astronomy-the scientific study of the solar system, the galaxy and the universe.

astrology-the belief that the movements of the Sun, Moon and planets affect people's personalities and events in their lives.

atmosphere-the outer layer of gases that surrounds a planet. axis-the line going through the North and South Poles.

comets-icy bodies which grow long tails of gas and dust when they come near the Sun.

craters-a circular dent on a planet's surface that is caused by the impact of a meteorite.

eclipse-the moment when the Moon blocks the Sun's light from the Earth or the Earth throws a complete shadow over the Moon.

galaxy-a large cluster of billions of stars, held together by gravity. There are millions of galaxies in the universe.

gravity -the force that pulls objects towards the ground. Gravity gives objects weight.

light year-the distance a beam of light travels through space in one year-about 9,500 billion km. Distances in space are measured in light-years.

meteor-a streak of light in the sky caused by pieces of rock or dust particles from space that burn up as they pass through the Earth's atmosphere.

meteorite-a piece of space rock or metal that impacts on a surface of a planet or moon.

meteoroid-a piece of rock or metal in space. orbit‑the path that one object in space takes around another.

planet-a large object that moves around the Sun. solar‑means'of the Sun'.

star-a glowing ball of gas that gives off its own heat and light.

universe-the whole of space and everything in it.