Our solar system

• Light-time is the distance which light travels within a specific period of time
• 1 light-second is 186,000 miles which can be converted to 300,000 kilometres
• AU (Astronomical Unit) Is the distance where 1AU is distance from the sun to earth)
• A Satellite is a celestial object (celestial meaning 'in outer space') that orbits another celestial body. There are 2 types:

  • Artificial
  • Natural
• Orbit is the curved path of a celestial object or spacecraft round a star, planet, or moon, especially a periodic elliptical revolution
• Gravity provides the force that allows planets and satellites (both natural and artificial) to maintain their circular orbits.
• The difference between the four inner and outer planets are that:

  • The four inner planets are closer, hotter, made of rock and are smaller.
  • The four outer planets are further away, colder, made of gases, have more moons, longer orbital periods and are larger.
• A galaxy is a collection of billions of stars