The solar system: Space physics: Physics: GCSE (9:1)

• Solar system


  A system of celestial bodies including a star, planets, other bodies that orbit the star, and moons that orbit the planets

  
• Celestial body


  Any naturally occurring object outside of the Earth's atmosphere

  
• Orbit


  The path that a celestial body follows as it travels around another

  
• The Sun


  The star at the centre of our solar system that has a large enough gravitational field to keep the planets, dwarf planets, asteroids and comets in orbit around it

  
• Gravitational field


  The region of space surrounding an object with mass in which another object with mass experiences a (non-contact) force

  
• Planet


  A large, spherical body in space that orbits a star

  
• Conditions required for a planet to form

  Its gravity must be strong enough to make it round/spherical in shape and clear the is orbital path (by pulling smaller, nearby objects into its orbit)
• Planets in our solar system

  Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune

  
• Dwarf planet


  A small, spherical body that orbits a star but its orbital path is not clear of other objects

  
• Dwarf planets in our solar system

  Pluto, Ceres, Makemake, Haumea, Eris

  
• Satellite

  A natural or artificial body that orbits a planet

  
• Moon


  A natural satellite of a planet

  
• Asteroid

  A small body of rock orbiting a star

  
• Asteroid belt


  The region of the solar system between orbits of Mars and Jupiter where many asteroids are found

  
• Comet

  A small body of ice, rock, and dust that follows an highly elliptical orbital path around a star

  
• Comet's tail


  A trail of gas and dust that is given off by a comet as it passes close to a star and points away from the star