Scientists Are Hoping to Make Pluto a Planet Again

Nearly 15 years after the International Astronomical Union reclassified Pluto as a dwarf planet, a group of researchers is hoping the international space body will reconsider its stance. In a new study published in the latest issue of the journal Icarus, a group of scientists suggests IAU’s definition of a planet is based on outdated science. Not only does this new group believe that Pluto should be a planet, but most satellite bodies currently considered moons should be planets as well.

“Unfortunately, sometime after 1920 but before the birth of modern planetary science in the 1960s, the astronomical community had lost interest in planets and during that period abandoned Galileo’s key insight, reverting to an astrological folk taxonomy received from culture,” the study reads.

It adds, “That folk taxonomy is the idea that planets are a small set of predictable objects that orbit a common center and depict orderliness and teleological meaning in the cosmos, which the culture carried over from geocentrism and astrology. Astronomers have forgotten that this is the origin of the folk taxonomy and now wrongly teach that this was the concept that scientists developed from the Copernican Revolution.”

In an August 2006 ruling, the IAU said Pluto fell short of meeting all of the criteria needed to be recognized as a full-fledged planet. At the time, the body said Pluto “has not cleared its neighboring region of other objects” with some suggesting Pluto was rather part of a kind of asteroid belt or something similar.

The IAU then reclassified the ninth rock from the Sun a “dwarf planet” because of its failure to meet all the criteria. The other two criteria involved included a body’s ability to orbit the Sun, and the body having “sufficient mass to assume hydrostatic equilibrium,” meaning the body is a round shape. Pluto meets two of the three conditions.

The researchers now suggest the IAU should update the criteria it considers when determining what celestial bodies should become planets.

“We present evidence that taxonomical alignment with geological complexity is the most useful scientific taxonomy for planets. It is this complexity of both primary and secondary planets that is a key part of the chain of origins for life in the cosmos,” the study’s abstract concludes.

You can read the study—Moons are planets: Scientific usefulness versus cultural teleology in the taxonomy of planetary science—in its entirety here.

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