Pluto has been the subject of the day on April 29, and the question was if it should be a planet or not? The Philosophical Society of Washington held the debate through a live stream on the PSW website.
The one that fights for Pluto’s status is Alan Stern, the principal investigator of the New Horizon mission. Stern says that they have to define planethood, and he suggests that an object could be a planet if its body is massive enough and has a round shape, but not extensive enough for nuclear fusion inside of it.
Pluto might be cataloged as a planet, again
After Alan Stern has argued in favor of Pluto, 130 participants have voted in favor, and 30 were against. On the other hand, a definition of planethood given by the International Astronomical Union says that a planet must orbit the Sun and have a round shape, and its orbit to be clear. But the discoveries made in 2015 by the New Horizon have revealed that Pluto has massive mountains, an internal ocean, and a thin atmosphere. All of this evidence has made Stern and other members to argue for Pluto and its status.
Despite that, the IAU is still against the idea of Pluto being a planet. IAU was the one that asked the Planetary System Division to create a definition of a planet. Ron Ekers from IAU is arguing that Pluto is a small object versus other planets, and the idea is to find an agreement on how to name things, so the vote is not about science.
Finally, Pluto’s status was taken in 2006 after IAU has organized a meeting in Prague, where the majority of the members have voted for Pluto being redesigned as a dwarf planet. Unfortunately, after a lengthy debate, the pros and cons of the two voices of the PSW debate, Pluto’s status didn’t change.