The structure of the universe

• What is anything that orbits a planet called?

  Satellite
• What distinguishes natural satellites from artificial satellites?

  Natural satellites aren't man-made
• What are artificial satellites used for?

  Communication and orbiting telescopes
• How many planets orbit the sun?

  Eight
• Name the planets in our solar system.

  Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune
• What type of orbit do planets have around the sun?

  Slightly elliptical orbit
• How do asteroids differ from comets?

  Asteroids are mostly rock and metal
• Where are asteroids mainly found?

  In the asteroid belt
• What are comets primarily made of?

  Ice and dust
• How do the orbits of comets compare to those of planets?

  Comets have much more elliptical orbits
• What is the name of our galaxy?

  The Milky Way Galaxy
• What do galaxies consist of?

  Billions of stars
• How does our solar system relate to the Milky Way Galaxy?

  Our solar system is a tiny speck in it
• What holds stars together in a galaxy?

  Gravity
• How do stars in a galaxy move?

  They spin around the middle
• What is the universe mostly filled with?

  Empty space
• What is the relationship between galaxies and the universe?

  The universe is scattered with galaxies
• How do solar systems relate to stars and planets?

  Solar systems consist of a central star and planets
• What can orbit planets like Earth?

  Satellites
• What are the key components of the solar system?

  • Central star (the Sun)
  • Eight planets (Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune)
  • Natural satellites (e.g., the Moon)
  • Artificial satellites (e.g., communication satellites)
  • Asteroids (mainly in the asteroid belt)
  • Comets (made of ice and dust)
• What is the structure of the universe?

  • Vast expanse of mostly empty space
  • Scattered with galaxies
  • Galaxies contain billions of stars
  • Many stars have their own solar systems