RENEE MONTAGNE, HOST:
Good morning. I'm Renee Montagne. Caltech astronomer Mike Brown helped prove Pluto is not a true planet. Brown tweets under the handle plutokiller. But his young daughter does not approve. She wanted Pluto to stay a planet, and she said she wouldn't forgive him until he discovered a brand new one. Now he thinks he has. Brown and another astronomer say small bodies appear to be orbiting a giant icy planet far beyond Pluto called Planet Nine. Thanks, Dad. It's MORNING EDITION. Transcript provided by NPR, Copyright NPR.
