25. Are the orbits of most comets like the orbits of the planets? 26. What may be the source of our solar system’s short period comets?27. In which direction are comets’ tails pointed?28. What is the “coma”?29. Which world was discovered by the use of a blink comparator? 30. What is the resonance between Neptune and Pluto? 31. What is unique about the Pluto-Charon system? 32. What observations finally gave us good data about Pluto and Charon? 33. Why do many argue that Pluto is not truly a planet? Do all astronomers agree? 34. How many moons does Pluto have? Why are they most likely there?
35. To date, what is the only spacecraft to visit Pluto? 36. Does Pluto have any surface features? 37. Where are the Kuiper belt objects located? 38. What do we call a tiny bit of debris located in space? 39. What is happening on the night of a meteor shower? 40. What event appears to have wiped out the dinosaurs about 65 million years ago? 41. What are exoplanets? How many do we know exist today? 42. What are the two main ways that we can detect them? 43. Have we ever directly imaged an exoplanet? 44. What is the habitable zone of a star?