Recent news seem to suggest that astronomers are arguing about whether Pluto should become a planet again.
However, I cannot find an official source for this. Is this actually true?
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Yes, Pluto is still a dwarf planet. According to the IAU website, it still fits the criteria for a dwarf planet, fails to meet the criteria for a planet, and still carries the "dwarf planet" label, whatever its future status may be. I'm sorry I can't provide a longer or more detailed answer, but this is really a yes-or-no question.
A lot of the push to have Pluto reinstated as the 9th planet is coming from Harvard, from their press release Is Pluto a Planet? The Votes Are In (Released September, 2014), they state the following outcomes from a debate:
Science historian Dr. Owen Gingerich, who chaired the IAU planet definition committee, presented the historical viewpoint. Dr. Gareth Williams, associate director of the Minor Planet Center, presented the IAU's viewpoint. And Dr. Dimitar Sasselov, director of the Harvard Origins of Life Initiative, presented the exoplanet scientist's viewpoint.
Gingerich argued that "a planet is a culturally defined word that changes over time," and that Pluto is a planet. Williams defended the IAU definition, which declares that Pluto is not a planet. And Sasselov defined a planet as "the smallest spherical lump of matter that formed around stars or stellar remnants," which means Pluto is a planet.
We will have a better understanding of Pluto, hence its classification when NASA's Horizons mission reaches it. But, at this stage, Pluto is still classified as a dwarf planet.
Pluto will continue to be exactly Pluto no matter how we choose to categorize it. Fretting about the "proper" category is the tyranny of the discontinuous mind.
Currently, Pluto is very much a dwarf planet. I don't think Pluto will ever be reinstated as a planet again . . . On the the pro-planet side, Pluto has five moons, which can possibly qualify it as a planet. On the no-planet side, Pluto has a mass of 1.30900 × 10^22 kilograms, which is much lower than the currently smallest planet, Mercury, which weighs 328.5 x 10^21 kilograms. Also, the diameter of Mercury is 4,879.4 km across, while Pluto’s diameter is 2,360 km across. Big difference. Really. I'm pretty sure Pluto won't be called a planet again, but I can't be certain. Look, here's the thing about controversies like this: you never know until they're over. Yes, it's a horrible answer, but it's the candid truth. At least I've given you the data.
The 3rd requirement for a celestial object to be a planet is that it has to "clear its neighborhood" which means it has to be gravitationally dominant. Pluto has not enough mass to interact with other object in its orbit(consuming them or swinging them away) and it is only 0.07 times the mass of the other objects in its orbit. Earth is 1.7 million times the mass of other objects in its orbit.