Stars and Planets

• What is our central star?

  Sun
• How many inner rocky planets are there?

  Four
• What are the four rocky inner planets?

  • Mercury
  • Venus
  • Earth
  • Mars
• How many outer gaseous planets are there?

  Four
• What are the four outer gaseous planets?

  • Jupiter
  • Saturn
  • Uranus
  • Neptune
• How many planets are in our solar system?

  Eight
• Where is the asteroid belt located?


  Between Mars and Jupiter
• What is in the asteroid belt?

  Rocks, dwarf planets and comets
• What are comets?


  Balls of rock and ice
• What are asteroids?


  Large rocks mainly found in the asteroid belt
• Where are stars born?

  In clouds of hydrogen gas and dust
• How do stars produce energy?


  By nuclear fusion
• What do hydrogen atoms fusing to form helium atoms produce?

  Lots of heat
• Hydrogen gas atoms fuse to form helium atoms
• Large mass stars are very hot
• Large mass stars have a relatively short lifetime
• What colour are hot, bright stars?

  Blue
• What colour are small, cold or dying stars?

  Red
• What do planets orbit?

  The sun/central star
• The time taken to orbit increases with distance from the sun
• What does gravity do for planets?

  Keeps them in orbit
• What type of orbit do planets orbit in?

  An elliptical orbit
• Moons are natural satellites
• What are planet diameters measured in?

  Metres and kilometers
• What is the distance between the sun and planets measured in?

  Astronomical units (AU)
• What is the distance between earth and other stars measured in?

  Light years
• What galaxy is earth in?

  The Milky Way
• What is each light in a galaxy?

  A star
• What show the observable universe to humans?

  Telescopes
• How did our solar system form?

  1. Dense, hydrogen rich cloud of dust and gas contracts under gravity
  2. As it compresses, the temperature increases and the cloud begins to spin
  3. A protostar starts to form at the centre of the spinning cloud
  4. Nuclear fusion starts and a star is born
  5. The planets form from the dust clouds around the star
  6. Gravity is greater closer to the star so the most dense material ends up there
• What is the first stage of a star?

  Protostar
• What is the second stage of an average mass star?

  Average main sequence star
• What is the second stage of a large mass star?

  Massive main sequence star
• What is the third stage of an average mass star?

  Red giant star
• What is the third stage of a large mass star?

  Red supergiant star
• What is the fourth stage of an average mass star?

  White dwarf
• What is the fourth stage of a large mass star?

  Supernova
• What is the final stage of an average mass star?

  Black dwarf
• What is the final stage of a large mass star?

  Neutron star or black hole
• When does a neutron star form?

  If the star was high mass