Whether Pluto exists or not has for a long time remained a bone of contention. In 1930, Pluto became the ninth planet of the solar system. It was bizarre that was far from home and very cold indeed. 75 years down the line, there was a discovery regarding the last entry in the solar system. What was it? The International Astronomical Union (IAU) declared that Pluto was a “dwarf planet” in 2006. It was not only a new category but also one that just Pluto was a member. According to them, Planet exhibited a big difference compared to other planets. What were the bases of their argument?

They laid down what makes a planet illegible. There were three conditions that it had to meet. The first one is the fact that it had to orbit around the sun. On that point, they ruled any other object including the moon. Secondly, its size must be significant. Therefore, its gravity would be able to round it into either a sphere or a spheroid. However, it shouldn’t be too big to the extent that its inner walls harbour the fusion reactions that give the stars their power. Last but not least, any other orbiting body must not be in its neighbourhood.

If you are wondering which conditions Pluto met and the ones it did not, here is the answer. When it comes to the first and second condition, Pluto could have been a member beyond any reasonable doubt. Nevertheless, the third one made Pluto lose the qualification of being one.

Many people including their allies and other scientists came to its rescue. Rule number one for instances wasn’t fair. If it was, then the Milky Way galaxy’s exoplanets cannot be planets either. Alan Stern didn’t agree with the same condition that nullified the Planethood of Pluto. Who better to argue than him? During the New Horizon mission to Pluto by NASA in July 2015, he was the principal investigator. He claimed that IAU just wanted to have a solar system with some planets easy to manage.

That brings as to the fact that the debate is back. The release of a book by the name Chasing New Horizons: Inside the Epic First Mission to Pluto provoked it. It is about the visit to the planet. Its authors are both Stern and David Grinspoon. David is a renowned planetary scientist. The two wrote a piece about their opinions with the title “Yes, Pluto is a Planet”. The publishing of the article by The Washington Post was on Monday, 7th May 2018. Whether the piece solved the mystery or not will remain a topic of discussion.