Universe structure

• Satellite


  Anything that orbits a planet
• Types of satellites


  • Natural
  • Artificial
• Natural satellite


  Not man-made
• Planets in the solar system

  • Mercury
  • Venus
  • Earth
  • Mars
  • Jupiter
  • Saturn
  • Uranus
  • Neptune
• Orbit of planets


  • Slightly elliptical, not a perfect circle
• Other structures in the solar system

  • Asteroids
  • Comets
• Asteroids


  Mostly made of rock and metal, found in the asteroid belt between Mars and Jupiter
• Comets


  Mostly made of ice and dust, have very elliptical orbits and travel to the outskirts of the solar system
• Galaxy


  Massive collection of billions of stars, most with their own solar systems
• Milky Way galaxy


  The galaxy that our solar system is a part of
• Gravity


  • Holds the stars in a galaxy together, causing them to spin around the middle
• Universe


  Scattered with galaxies, mostly empty space with unimaginable distances between adjacent galaxies
• The universe is a vast expanse of mostly empty space scattered with galaxies, which themselves are collections of billions of stars many of which have their own solar systems, and solar systems consist of a central star orbited by planets like Earth, which themselves can be orbited by satellites like the moon