structure of the universe

• what is anything that orbits a planet called?

  a satellite
• satellites can be _______ or __________

  natural, artificial
• is the moon a natural or artificial satellite?


  natural
• what are natural satellites?

  satellites that aren't man-made
• what are artificial satellites?

  satellites that are man-made
• what are examples of artificial satellites?

  • satellites used for communication
  • orbiting telescopes
• how many plants are in the solar system?

  8
• what do the plants orbit?

  the sun
• what are all 8 planets called?

  Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune
• all 8 planets orbit the sun in an elliptical orbit, what does that mean?


  the path they take isn't a perfect circle
• what are asteroids? 


  made of mainly rock and metal. they are found mainly in the asteroid belt, which is between mars and jupiter.
• what are comets?


  made of ice and dust. travel on more elliptical orbits while orbiting the sun and often travel to the outskirts of the solar system.
• what is our galaxy called?

  the milky way
• what are galaxies?


  massive collections of billions of stars, most of which have their own solar systems.
• what force holds all the stars of the Milky Way together?

  gravity
• what do all of the stars of the Milky Way do?

  orbit the middle like how planets orbit the sun
• what is the universe?

  scattered with galaxies, mostly empty space with unimaginable distances between adjacent galaxies