Most of us grew up learning that there are nine planets in our solar system – Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto. But one day, back in 2005, Pluto got the shaft. A Caltech astronomer named Mike Brown rocked the universe when he discovered a tenth planet – Eris. First known as Xena, this planet was 27% more massive than Pluto, making it the largest object found in our solar system in 150 years. But instead of being great news for planets everywhere, a firestorm of debate ensued. Rather than embracing Eris, astronomers demoted Pluto to a mere dwarf planet. In his new book, How I Killed Pluto and Why It Had It Coming, Brown ‘fesses up to his part in the scientific shocker of the century. Did Pluto die in vain? What other discoveries are trouble-making, star-gazers likely to stir up?

Guest:

Mike Brown, author of How I Killed Pluto and Why It Had It Coming (Spiegel & Grau); Professor of Planetary Astronomy at the California Institute of Technology (Caltech)