# The table below lists the average distance R to the Sun and orbital period T of the first planets: (a) Calculate the average distance of Mercury, Venus and Mars to the Earth. Which one of these planets is the closest to Earth on average? (b) Calculate the average distance of Mercury, Venus and Earth to Mars. Which one of these planets is the closest to Mars on average? (c) What do you expect for the other planets? Hint: Assume circular orbits and use symmetries to make the distance calculation easier. You can approximate the average distance by using four well-chosen points on the planet’s orbit.   Distance Orbital Period Mercury 0.39 AU 88 days Venus 0.72 AU 225 days Earth 1.00 AU 365 days Mars 1.52 AU 687 days

Question

The table below lists the average distance R to the Sun and orbital period T of the first planets:

(a) Calculate the average distance of Mercury, Venus and Mars to the Earth. Which one of these planets is the closest to Earth on average?

(b) Calculate the average distance of Mercury, Venus and Earth to Mars. Which one of these planets is the closest to Mars on average?

(c) What do you expect for the other planets?
Hint: Assume circular orbits and use symmetries to make the distance calculation easier. You can

approximate the average distance by using four well-chosen points on the planet’s orbit.

 Distance Orbital Period Mercury 0.39 AU 88 days Venus 0.72 AU 225 days Earth 1.00 AU 365 days Mars 1.52 AU 687 days