The gas giants serve some purpose in the solar system, and each one has an interesting collection of moons. Mars and Venus have fantastic landscapes, so that leaves Mercury and Pluto.
On Mercury the sun rise isn't linear - due to its orbit and rotation, and Kepler's second law of planetary motion, the sun will occasionally reverse direction in the sky. That is awesome.
Pluto isn't a proper planet. I say get rid of it.
Aenir said:
I'll be honest: I clicked just hoping you'd include Pluto.
It deserves some kind of honorary planet status.
Being both a dwarf planet and the namesake of plutoids seems like a fair bit of recognition. I don't see what Pluto has done to deserve "honorary planet status" that Ceres didn't do nearly a hundred and fifty years before.
Now I do think Tombaugh deserves are more attention than he gets. The fact that he discovered this miniscule icy body decades before more were found is astounding. I say it's time for Pluto to become a sidelined astronomical factoid and Tombaugh to get more public attention.