Pluto

On January 5, 2005, the Palomar Observatory-based team led by Mike Brown discovered a large world, later known as Eris, after systematically scanning for large outer Solar System bodies for several years. Unfortunately for Pluto, this was the beginning of the end for its official planet title.

On this day 15 years ago, children across the world had to come up with a new way to remember the names of the planets in the solar system. No more pizzas were coming from our educated mothers, instead it would be… nachos?