Dec 11, 2021 05:06 AM
https://www.sciencealert.com/fascinating...tate-pluto
INTRO: The International Astronomical Union (IAU) has a very strict definition of the word "planet". According to the definition – drafted, tweaked, and agreed upon in August 2006 – an astronomical body is officially a planet if it orbits the Sun, has sufficient mass to be spherical, and has cleared the neighborhood around its orbit.
Under these strictures, only eight bodies in the Solar System can be considered planets: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. This definition very effectively cut out Pluto, a move that has proven, at the very least, extremely controversial, with many scientists calling for a more inclusive redefinition based solely on the physical properties of the body in question.
Which brings us to a new paper that has bolstered those bids with an in-depth analysis of the IAU criteria. Those criteria, the paper finds, are not based on science after all; instead, they rely on folklore and astrology.
Led by planetary scientist Phillip Metzger of the University of Central Florida, the researchers urge that the third criterion in particular be rescinded, and the definition of a planet be simplified: that the body is, or has been, geologically active.
This would put many Solar System bodies in the planet category, including Earth's Moon and many other moons, dwarf planets, and even asteroids – an outcome that has previously been used as an argument against expanding the definition.
But the fact that these bodies are similar enough that they could be grouped together is a compelling reason why they should be, the researchers behind the new study say... (MORE)
INTRO: The International Astronomical Union (IAU) has a very strict definition of the word "planet". According to the definition – drafted, tweaked, and agreed upon in August 2006 – an astronomical body is officially a planet if it orbits the Sun, has sufficient mass to be spherical, and has cleared the neighborhood around its orbit.
Under these strictures, only eight bodies in the Solar System can be considered planets: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. This definition very effectively cut out Pluto, a move that has proven, at the very least, extremely controversial, with many scientists calling for a more inclusive redefinition based solely on the physical properties of the body in question.
Which brings us to a new paper that has bolstered those bids with an in-depth analysis of the IAU criteria. Those criteria, the paper finds, are not based on science after all; instead, they rely on folklore and astrology.
Led by planetary scientist Phillip Metzger of the University of Central Florida, the researchers urge that the third criterion in particular be rescinded, and the definition of a planet be simplified: that the body is, or has been, geologically active.
This would put many Solar System bodies in the planet category, including Earth's Moon and many other moons, dwarf planets, and even asteroids – an outcome that has previously been used as an argument against expanding the definition.
But the fact that these bodies are similar enough that they could be grouped together is a compelling reason why they should be, the researchers behind the new study say... (MORE)
