“A planet is…” Scientists have proposed to change the definition of a planet, because the old one is outdated
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Planetary scientists from the University of California at Los Angeles and colleagues have proposed a new definition of a planet for the International Astronomical Union (IAU). This organization officially names all space objects and in 2006 adopted the current definition, in which one of the criteria is the rotation of a celestial body around the Sun. And this immediately weeds out all the celestial bodies around other stars outside our Solar System.
Other criteria in the definition of MAC, on the contrary, lack specificity, scientists believe. An article with their new definition and detailed arguments has been published on the arXiv preprint server.
At the moment, according to the IAU classification, a planet is considered to be a celestial body orbiting the Sun, massive enough to take a spherical shape under the influence of its gravity and remove other objects near its orbit.
“Now we know about the existence of thousands of planets, but the definition of the IAU does not apply to them. We propose a new definition that can be applied to celestial bodies orbiting any star, stellar remnant or brown dwarf,” planetary scientist and astrophysicist Jean-Luc Margot, professor at the University of California at Los Angeles.
