space

• What is our Solar System made up of?

  The Sun and orbiting objects
• How many planets are in our Solar System?

  Eight planets
• What type of celestial object is the Sun?

  A star
• In which galaxy is the Solar System located?

  The Milky Way galaxy
• What causes the Sun to be stable?

  Fusion reactions balance gravitational forces
• What determines the life cycle of a star?

  Its mass
• What is the starting point of all stars?

  A nebula
• What happens to stars with the same mass as the Sun?

  They follow specific life cycles
• How are naturally occurring elements formed?

  Through nuclear fusion in stars
• What is produced when hydrogen nuclei fuse together?

  Helium nuclei
• What elements are formed in massive stars?

  Helium, lithium, and larger nuclei
• What is a supernova?

  A massive star explosion
• How are elements heavier than iron produced?

  During a supernova explosion
• What role does gravity play in orbital motion?

  It provides the centripetal force
• What is a natural satellite that orbits the Earth?

  The Moon
• What type of orbits do the Moon and artificial satellites have?

  Circular orbits
• What is the centripetal force?

  The resultant force towards the orbit's center
• How does an object in a circular orbit change its velocity?

  By changing direction, not speed
• What must happen for an object to stay in a stable orbit?

  It must move at a particular speed
• What happens if the speed of an object in a stable orbit changes?

  The radius of the orbit must change
• What is red-shift?

  Longer wavelengths if moving away
• What does red-shift suggest about distant galaxies?

  They are moving away from Earth
• What does the observation of red-shift indicate about the universe?

  The universe is expanding
• What does the Big Bang theory propose?

  The universe started as a small, dense object
• What evidence supports the Big Bang theory?

  Red-shift and electromagnetic radiation
• What is dark energy thought to be responsible for?

  The acceleration of the universe's expansion
• What are the key terms related to the study material?

  • Big Bang theory
  • Centripetal force
  • Dark energy
  • Dark matter
  • Milky Way galaxy
  • Nebula
  • Orbit
  • Supernova
  • Gravitational attraction
  • Protostar
• What is dark matter believed to provide?

  The gravitational force holding galaxies together
• What is the life cycle of a star with about the same mass as the Sun?

  Protostar → main sequence star → red giant → white dwarf → black dwarf
• What is the life cycle of a star with much more mass than the Sun?

  Protostar → main sequence star → red supergiant → supernova → neutron star or black hole