Last year, astronomers at Cal Tech discovered an object they called Xena--even bigger than Pluto, and also orbiting around the Sun. That set off an astronomical controversy. Are there really 10 planets? Today, the International Astronomical Union said, "No." Xena isn't a planet at all, and neither is Pluto. Planetary astronomer Mike Brown led the CalTech team that discovered Xena. (An extended discussion on this subject was originally aired earlier today on To the Point.)
Pluto Demoted
Credits
Guest:
- Mike Brown - Professor of Planetary Astronomy, California Institute of Technology - @plutokiller