Revise GCSE Physics


P2g Threats to Earth

  1. What is the most likely origin of the Moon?
  2. Can you describe how a two planet collision could result in an Earth-Moon system?
  3. What evidence is there for this theory?
  4. What are Asteroids?
  5. Why is the surface of the Moon covered in craters?
  6. Why does the surface of the Earth not look similar to the surface of the Moon?
  7. What would happen here on Earth if a large asteroid where to strike the surface of the Earth?
  8. Where did Asteroids come from?
  9. Where are most of the asteroids in the Solar System?
  10. What is responsible for the asteroid belt between Mars and Jupiter?
  11. What three pieces of evidence suggest that craters on Earth were caused by asteroid collisions?
  12. What evidence is there for life on Earth being threatened in the past by Asteroid collision?
  13. What is a comet composed of?
  14. Where do comets come from?
  15. Why do comets sometimes have tails?
  16. What type of orbits do comets have?
  17. How does the speed of a comet change as it travels along its orbit?
  18. What are Near Earth Objects?
  19. How do we know about NEO's?
  20. Why is it difficult to observe NEO's?
  21. What does "trajectory" mean?
  22. How do we work out the trajectory of an NEO?
  23. What can be done to reduce the risk to life on Earth of NEO's?
  24. How can a Near Earth Object be prevented from striking the Earth?