9B. DWARF PLANET (KUIPER BELT) – PLUTO Pluto was the ninth planet in our solar system for 76 years. In 2006 it was reclassified a dwarf planet. It is the first object humans discovered in the Kuiper belt – kind of like a bigger version of the asteroid belt that lies beyond Neptune. In 2015 the first human spacecraft visited Pluto and took a gazillion pictures. In this one we see Pluto’s blue haze which is the product of sunlight shining onto methane molecules. Pluto’s really small. It’s smaller than Earth’s moon. Still it has five moons of its own. This is Charon – the biggest one. This is part of Pluto’s “heart” called the Sputnik Planitia. It’s made of nitrogen ice and is about the size of Hudson Bay. These are some of the mountains on Pluto. They’re as tall as many of Earth’s mountains.