42: The Answer to Almost Everything - Season 1 Episode 185 Does Planet Nine Really Exist?
9.6048 minutes
In 2006, the International Astronomical Union voted to demote Pluto to a "dwarf planet," reducing the official number of planets in the solar system to eight. According to Mike Brown, the astronomer behind Pluto's declassification, there is, however, a wealth of evidence suggesting the existence of a ninth planet.