Astronomy

• What is the main focus of the GCSE Edexcel astronomy topic?

  Solar system, gravity, redshift, Big Bang
• What is the solar system composed of?

  The Sun and all orbiting objects
• How many stars are in our solar system?

  One star, the Sun
• Why does the Sun appear large to us?

  It is the closest star to Earth
• What are the four terrestrial planets in order?

  Mercury, Venus, Earth, Mars
• Why are terrestrial planets called that?

  They are small, rocky, and have solid surfaces
• What is located after Mars in the solar system?

  The asteroid belt
• What is the composition of the asteroid belt?

  A ring of asteroids around the solar system
• What are the four gas giants in the solar system?

  Jupiter, Saturn, Uranus, Neptune
• Why are gas giants called that?

  They are primarily composed of gases
• What is unique about Saturn?

  It has prominent rings around it
• What is the Kuiper belt?

  A region beyond Neptune with icy bodies
• Why is Pluto classified as a dwarf planet?

  It has not cleared its orbit
• What was the historical belief about the solar system before the 1500s?

  It was geocentric, with Earth at the center
• What evidence led to the belief that the Sun is at the center of the solar system?

  Galileo's discovery of Jupiter's moons
• What is the definition of an orbit?

  To go around another object
• What is the gravitational field strength on Earth?

  10 Newtons per kilogram
• How does gravitational field strength differ on the Moon?

  It is 1.6 Newtons per kilogram
• What factors affect surface gravity?

  Mass and radius of the planet
• What happens to the gravitational field strength as radius increases?

  It decreases for a given mass
• What is the relationship between mass and gravitational field strength?

  More mass means higher gravitational strength
• What is centripetal force in the context of orbits?

  It is the force acting towards the center
• How does a satellite maintain its orbit?

  By balancing gravitational force and inertia
• What is a geostationary orbit?

  It stays over the same spot on Earth
• What are the main sections of the GCSE Edexcel astronomy topic?

  • Solar system
  • Gravity and orbits
  • Redshift and the Big Bang Theory
  • Stellar evolution
  • Methods of observing the universe
• What are the characteristics of terrestrial planets?

  • Small and rocky
  • Have solid surfaces
  • Suitable for life
• What distinguishes gas giants from terrestrial planets?

  • Composed mainly of gases
  • Much larger in size
  • May have solid centers
• What is the significance of Galileo's observations of Jupiter's moons?

  • Provided evidence against geocentrism
  • Showed that not everything orbits Earth
• What are the types of orbits in the solar system?

  • Planetary orbits around the Sun
  • Moons orbiting planets
  • Comets with highly elliptical orbits
• What is the relationship between gravitational field strength and density?

  • Higher density leads to higher gravitational strength
  • Lower density leads to lower gravitational strength
• What is the effect of increasing the radius of an orbit on speed?

  • Larger radius requires slower speed
  • Smaller radius requires faster speed
• What are the common types of orbits around Earth?

  • Geostationary orbit
  • Low Earth orbit
  • Polar orbit
• What happens to gravity as you move further from an object?

  Gravity decreases with distance from the object
• How does the radius of orbit affect the speed of a satellite?

  A larger radius requires a slower speed
• What must you do to move a satellite to a lower orbit?

  Slow it down gradually
• What are the two most common types of orbits around Earth?

  • Geostationary orbit
  • Polar orbit
• What is a geostationary orbit's period and its significance?

  It has a period of one day, staying over the same spot
• Why are geostationary satellites important for satellite TV?

  They remain fixed over the same location
• What is the main use of polar orbits?

  They cover the entire Earth for mapping
• What is an example of a satellite that uses polar orbit?

  Google Earth