Pluto is again suggested to be the planet

Pluto is again suggested to be the planet

Astronomers have proposed to revise the criteria for the distinction of the planets. According to new idea, Pluto needs to obtain again the lost status of full-fledged planet of the Solar system. The study is published in the journal Icarus.


In 2006, the international astronomical Union (IAU) adopted a new definition of a planet. It includes several criteria, some of which argued that such a body must have sufficient gravity to “clean up” from other space bodies in close proximity. Pluto does not fit this definition, as it has a large and close companion Charon, and is about the same distance from the Sun, as other similar bodies in the Kuiper belt.

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In the new work of astronomers under the leadership of Philip Metzger of the University of Central Florida (USA) conducted a systematic analysis of the scientific literature and found that the standard cleaning of the orbit is used only once, in 1802, and today set out in that article, train of thought is considered to be erroneous. Moreover, experts are regularly called planets a moon of Jupiter Europe, and Saturn’s moon Titan. “The definition of WT means that the center of planetary science — the planet — is determined on the basis of criteria that no one uses, explains his point of view Metzger. — It also removes from the second class of complexity and interest to the called object”.

The authors come to the conclusion that in the scientific literature in the 1950s established a consensus on the topic of the differences between planets and other celestial bodies such as asteroids. Fundamental in this respect was the work of Gerard Kuiper, who proposed to distinguish them in the history of the formation. Scientists believe that the definition should be based on regular internal properties of the body, and not on those that can change, like the dynamics of the orbit. Astronomers propose that the main criterion to consider the presence of gravity, enough to give the body a spherical shape.