In-class test 3 for ASTR 201: The Sun and its Planets

Test will be the first 15 mins of class on Nov 4 and will comprise one of the following questions.

(1) It takes Venus 780 days to go from first to third conjunction with the Sun. Using diagrams, explain how you would use this information to calculate Venus' orbital period.

(2) The Sun's mass is slowly decreasing with time. Describe two processes that cause this. Is the decrease in mass large enough that we need to worry about its effect on the brightness of the Sun?

(3) What are neutrinos and why can we additional information about the Sun from detecting them? Briefly describe the reason scientists have difficulty in detecting neutrinos.

(4) Explain the balance of forces that stops the Sun from either expanding or contracting. Imagine that the nuclear reactions in the core slowed down temporarily; describe how the structure of the Sun would change because of this.

(5) If a new planet was discovered whose orbital motion around the Sun was in the opposite direction to all the other planets, would you deduce that it was formed in the same way as the other planets or a different way? Explain your reasoning.