I always did have trouble remembering Eris

But not any more. Now I have a new mnemonic to help remember the names of the 8 planets and three dwarf planets (Ceres, Eris and the recently demoted Pluto), courtesy of the winner of the Nation Geographic Planetary Mnemonic contest, 10 year old Maryn Smith from Montana. She came up with My Very Exciting Magic Carpet Just Sailed Under Nine Palace Elephants.

Full story here.