Should Pluto return planetary status? UCF scientist Philip Metzger is confident that it is. At least he thoroughly proves his point in his new research.
In 2006, the International Astronomical Union, which included a group of astronomy experts from around the world, established the definition of a planet, according to which the planet should have the highest gravitational force in a particular orbit. Since Neptune's gravity affects the neighboring planet Pluto, and Pluto shares its orbit with icy bodies and other objects in the Kuiper belt, according to this definition, Pluto can no longer be considered a planet.
In a new study published Wednesday in the journal Icarus, UCF planetary scientist Philip Metzger, who works at the Florida Institute in Florida, said this standard for classifying planets is not supported in the research literature.
Metzger, who is the lead author of the study, reviewed the scientific literature over the past 200 years and found only one publication (since 1802) that used the clearing orbit requirement to classify planets, and that was based on irrefutable reasoning.
He said that Saturn's moons like Titan and Jupiter's Europa have been regularly referred to as planets since the time of Galileo.
“It turns out that the IAU's definition of a 'planet' as a fundamental object of planetary science is based on a concept that nobody uses in their research,” Metzger said. 'And only because of this, we lose the second most complex and interesting planet in our solar system. We now have a list of over 100 recent examples of planetary scientists using the word 'planet' in a way that calls into question the IAU's definition, yet still insist on the functional validity of the definition. But the definition is very sloppy. They didn't say what they mean by clearing the orbit. If we talk about it literally, then we can say that the planets do not exist at all, since none of the planets is able to completely clear its orbit. '
The planetary scientist pointed out that a literature review noted the separation between planets and other celestial bodies such as asteroids in the early 1950s, when Gerard Kuiper published a paper that made a distinction based on how they were formed.
“We have shown that this is a false historical statement,” said Kirby Runyon of the Johns Hopkins University Applied Physics Laboratory, co-author of the study. 'It is a mistake to apply such arguments to Pluto. As Metzger correctly noted, the definition of a planet should be based on its intrinsic properties, and not on those that can change, for example, the dynamics of the planet's orbit. '
According to Metzger, the planet's orbit is a dynamic quantity. The scientist insists that the planet needs to be classified based on its size and gravity, which keeps it spherical in shape. Pluto has an underground ocean, a multilayered atmosphere, organic compounds, evidence of ancient lakes and several satellites, which, according to the planetary scientist, makes it possible to designate this object as more dynamic and alive than Mars and even more geologically complex than Earth.
