astronomy focus

• Descriptions of planets in the solar system

  • Mercury is the smallest rocky planet
  • Uranus is the seventh planet from the sun
  • Jupiter has a well-developed atmosphere like Earth
  • Jupiter is the largest gas giant
  • Uranus rotates on its side
• Meteor


  A meteoroid that is pulled into earth's atmosphere and burns up due to atmospheric friction (aka. a shooting star)
• Meteorite


  A meteoroid that is large enough to pass through earth's atmosphere and reach the ground without being totally burned up
• Meteoroid


  A small piece of metal or rock moving through space
• Comet


  A large chunk of ice, dust, and rock that orbit the sun (aka. a dirty snowball)
• Asteroid


  Small, non-spherical objects that are thought to be debris left over from the formation of the solar system
• A space probe has traveled approximately 2 250 000 000 km from Earth
• 2 250 000 000 km 150 000 000 km= 15 AU
• Spectrum


  Indicates which chemical elements make up a star
• Colour


  Indicates the star's surface temperature
• Mass


  Determines the length and stage of a star's life cycle
• Black hole


  An extremely dense quantity of matter in space from which no light or matter can escape
• White dwarf


  A small, dim, hot star that forms the remains of a red giant
• Red giant


  The second life of an intermediate sized star
• Nuclear fusion


  The process that takes place in the core of a star when temperatures exceed 10 million degrees Celsius
• Differences between stars and planets

  • Definition
  • Energy source
  • Composition
  • Temperature
  • Brightness
  • Size and Mass
  • Lifecycle
  • Gravitational Influence
  • Formation
  • Types
• Our solar system is a part of the milky way galaxy. It is a spiral galaxy
• Light-year


  The distance that light travels in a vacuum in one year
• Planets in order from closest to the sun to furthest from the sun

  • Mercury
  • Venus
  • Earth
  • Mars
  • Jupiter
  • Saturn
  • Uranus
  • Neptune
• The 4 closest planets to the sun are called the "terrestrial planets" because they have a hard and rocky surface
• A cooler star may look brighter than a hotter star


  Because of its apparent brightness, which is the brightness of stars as they are seen from earth
• Arranged in order of size, starting with the largest


  • Universe
  • Galaxy
  • Star cluster
  • Star
  • Planet
• Gravity is responsible for bringing together the particles found in space
• Features of Earth that make it unique in the solar system

  • Liquid water
  • Atmosphere
  • Moderate Climate
  • Plate Tectonics
  • Magnetic Field
• Features that make Earth well suited for life

  • Water
  • Moderate climate
• The big bang is estimated to occur about 13.7 billion years ago