Episode 08: The Frozen Dunes of Pluto

At the XXVIth General Assembly of the International Astronomical Union, held in Praague in August 2006, a new set of three criteria were decided to define what is — and what is emphatically *not* — a planet. Infamously, Pluto fulfilled only two of the three criteria, and so was unceremoniously dumped from the planet club, and reclassified as a "dwarf planet". A decade later, the New Horizons spacecraft swung past this tiny, frozen rock on the outskirts of the Solar System and reported back that Pluto is actually a pretty fascinating place, with a loads of cool suface features and even a thin atmosphere capable of creating dunes of solid methane! Dwarf planet it may be, but Pluto is still awesome.