Pluto is the most mysterious planet in the Solar System because it is the one that astronomers know least about. Many have questioned Pluto’s status as a planet, arguing that it is too small, and its orbit too elliptical, to be classified as such. Pluto may be the largest of the asteroids in the Kuiper Belt. Or it may once have been one of Neptune’s moons that broke free of its parent’s gravity. However, there are no plans to demote Pluto yet.
Pluto’s status as a planet has once again been called into question after the head of NASA said he believed the celestial body to be a planet. Speaking at the FIRST Robotics event in Oklahoma, NASA administrator Jim Bridenstine went against convention by placing himself firmly on one side of the Pluto debate.
“Just so you know, in my view Pluto is a planet,” he said. “You can write that the NASA administrator declared Pluto a planet once again. I’m sticking by that, it’s the way I learned it and I’m committed to it.” Pluto was first declared a planet in 1930 after it was discovered by American astronomer Clyde Tombaugh. At the time it was believed to be the ninth planet from the Sun, existing on the outer edges of the solar system in the Kuiper belt.
Its status as a planet was called into question 62 years later after other similarly-sized objects were discovered in the same region of space. In 2005, astronomers discovered a dwarf planet called Eris that was 27 per cent larger than Pluto. A year later, the International Astronomical Union laid out its official definition for what constituted a planet. Pluto was not included.
Since then it has been classified as a dwarf planet, though the icy object has attracted a dedicated following of people who claim Pluto should be considered a planet. In 2015 Nasa’s New Horizons mission to Pluto made several major discoveries that added fuel to the debate.
Pluto and Charon in synchronized Orbits. This means that they keep the same side, facing each other as they turn. From one side of Pluto, Charon always appears at the same point in the sky. On the other side of the planet, the moon is never visible.