8.10 - Astronomy - Universe, Galaxies & Solar System

• What is anything that orbits a planet called?

  Satellite
• What distinguishes natural satellites from artificial satellites?

  Natural satellites are not man-made
• What are artificial satellites used for?

  Communication and orbiting telescopes
• How many planets orbit the sun in our solar system?

  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
• What are comets primarily made of?

  Ice and dust
• Where are asteroids mainly found?

  In the asteroid belt
• 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?

  It is a tiny speck in the galaxy
• 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?

  Solar systems consist of a central star
• What do solar systems typically consist of?

  A central star orbited by planets
• What can orbit planets?

  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
• What is the significance of gravity in galaxies?

  • Holds stars together
  • Causes stars to spin around the center
• A satellite is any object that orbits a celestial body, such as a star or planet. 

  Is the moon a satellite?

  Yes
• What shape are the orbits of comets?

  Elliptical 
• The asteroid belt is a region of our solar system that contains millions of asteroids.

  Which two planets is the asteroid belt found between?

  Mars and Jupiter
• What is a comet mostly made of?

  Ice and dust
• What is an asteroid mostly made of?

  Rock and metal
• • A galaxy is a collection of billions of stars. 
  • Stars in a galaxy are held together by gravity.
  • Stars orbit around the centre of the galaxy.
  • Our solar system is in the Milky Way galaxy.
• True or false? The universe contains only a few galaxies.

  False

  The universe contains trillions of galaxies.
• Starting with the smallest, which of the following shows the correct order of size?

  Satellite, planet, solar system, galaxy, Universe
• Which statement is correct regarding satellites?

  An artificial satellite is man-made whereas a natural satellite is not man-made
• Which of the following are artificial satellites?

  (Select all that apply)

  Aeroplane 

  Hubble Space Telescope

  Moon

  International Space Station

  • Hubble Space Telescope
  • International Space Station