'A Planet Named Easterbunny'

-- Voyage to the Bunny Planet

by Rosemary Wells

Kids love the Bunny Planet books by Rosemary Wells. Maybe you failed a test, or ate a bad hot dog, or got in trouble for making rude noises on the school bus. No problem! Janet the Bunny Queen will make you feel better. If only the Bunny Planet were real -- it almost was.

A few years ago, astronomer Mike Brown of Caltech discovered a small planet. It was farther away from Earth than Mars is, farther away than Jupiter, farther even than Pluto. He found it a few days after Easter, so he decided to call it Easterbunny. The solar system finally had a bunny planet!

Mike Brown has discovered a number of small planets. Most of them are smaller than Pluto, so astronomers say they are "dwarf planets." Brown loves to give them nicknames. He named one Santa, because he found it around Christmastime. He called another one Xena, the Warrior Princess, and yet another one Snow White.

But these fun names didn't stick. There is a group of astronomers who belong to the International Astronomical Union, and they are in charge of naming things in the solar system. They told Mike that dwarf planets beyond Pluto must be named after mythological gods of creation. It's a rule!

So Mike and his team put on their thinking caps. They renamed Santa as "Haumea," a Hawaiian goddess of childbirth. They renamed Xena as Greek goddess "Eris." And they renamed Easterbunny as "Makemake," [pronounced ma-kay ma-kay] a creation god of Easter Island.

Eris was a goddess who loved to argue. Mike Brown named a dwarf planet after her because that planet made astronomers get mad and argue with each other.

When Mike Brown discovered Eris (then named Xena), he saw that it was larger than Pluto. People started thinking: If Pluto is a planet, and Xena is bigger than Pluto, then Xena must be a planet too! Newspapers around the world announced the discovery of a 10th planet. Mike Brown and the Warrior Princess were suddenly famous.

That's when the arguments started. Some astronomers thought Pluto was too tiny to be a planet, and they didn't think much of Xena either. Finally, the International Astronomical Union held a vote. Astronomers could vote yes, Pluto is a planet, or no, Pluto is not a planet. Pluto lost. Little planets like Pluto and Eris (Xena) are now called "dwarf planets."

Mike Brown remembers how he felt when he discovered Xena. "I immediately called my wife and excitedly told her 'I found a planet!' It was a great moment."