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Solar system may soon have 100+ planets with new criteria

Solar System A new definition of what is a planet would mean there are at least 110 planets in our Solar System.

Our solar system could contain over 100 planets if a new classification system is approved.

Tech Times explains that the definition of a planet was last changed by the International Astronomical Union (IAU) in 2006 when the new criteria famously demoted Pluto from the rank of a planet to dwarf planet and Kuiper Belt Object.  Space objects similar in size or larger than Pluto were discovered in Pluto’s neighborhood, and the discovery of Eris, which is larger than Pluto, contributed to the new definition of a dwarf planet.

The IAU criteria for a planet reads, “a celestial body that (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and (c) has cleared the neighborhood around its orbit.”

Because Pluto shares its orbit with more than a natural satellite, it does not meet the requirement for planetary status that requires a clear area throughout the planet’s orbit.

Now, a group of scientists is proposing that the definition of a planet be changed to consider the object’s shape and behavior without considering the object’s location or other bodies that may share its orbit.  The team points out that even Jupiter has not totally cleared its orbit of asteroids.

The group is suggesting a definition by which a planet is “a sub-stellar mass body that has never undergone nuclear fusion.” The object should possess enough gravitational pull to maintain a spherical shape, but any other space objects present in the planet’s surroundings are of no consequence in affecting the planet’s designation as such.

The newly proposed definition would reclassify objects such as Jupiter’s moon Europa and even Earth’s moon as planets.  Pluto would be reinstated as a planet as well.

If the new definition were to be accepted, the solar system’s planet count would jump from eight to around 110.

Kathy Fey

Kathy Fey

Staff Writer
Kathy Fey is a freelance writer with a creative writing degree from Mount Holyoke College. She is an active blogger and erstwhile facilitator of science and engineering programs for children.
About Kathy Fey (672 Articles)
Kathy Fey is a freelance writer with a creative writing degree from Mount Holyoke College. She is an active blogger and erstwhile facilitator of science and engineering programs for children.