Photo: JHUAPL / SwR / Globallookpress.com
Astrobiologist David Grinspoon (David Grinspoon) and researcher Alan stern (Alan Stern), working in the New Horizons program, I believe that Pluto is a planet. Their opinion cites The Washington Post.
According to scientists, the planet is any celestial body with specific geological and climatic characteristics, including the major natural satellites of planets, e.g. Titan (moon of Saturn), which is more mercury. Of the same type can be attributed to a space object that has sufficient gravity to have a spherical shape and consists of solid rock, ice or gas. This criterion allows to distinguish the planet from the small bodies of the Solar system, including comets and asteroids.
The researchers criticized the decision adopted by the conference of the International astronomical Union in 2006, when scientists redefined the definition of “planet” decided to refer to this class object rotating around the Sun and is able to clear the neighborhood of its orbit from smaller bodies. Grinspun and stern believe that as a result of the status of “planet” lose not only exoplanets, but even Land in the first 500 million years of its existence.
At the conclusion of the Union, a dwarf planet is not a planet. However Grinspun and stern emphasize that Pluto applies to dwarf planets like the Sun, which is a dwarf star. Scientists argue that the definition of “planet” should be based on geophysical features of the cosmic body, and not on its orbital characteristics.
Video, photo All from Russia.