I am really struggling with this question because I can't find anything on aphelion and perihelion, it's not a topic we went over because it is an extra assignment.
4. How far away from the sun was Mercury at aphelion? On what day did aphelion occur?
5. How far away from the sun was Mercury at perihelion? On what day did it occur?
6. How many days elapsed between aphelion and perihelion? What percent of the time to complete one orbit was this?
7. What was the average radius of Mercury in its orbit that you calculated? How does it compare to the accepted value of 0.387 AU? Calculate the percent error using the following equation. Show your work.
If someone could explain it to me I would really appreciate it!