A recent study published in The Planetary Science Journal proposes a new definition of a “planet” that could challenge the longstanding criteria established by the International Astronomical Union (IAU). The team of researchers from the United States and Canada, led by Dr. Jean-Luc Margot from the University of California, Los Angeles, aims to address the issues with the current IAU Resolution B5, which was established in 2006 and led to the demotion of Pluto from a planet to a dwarf planet.
The current IAU definition requires a celestial body to orbit the Sun, be nearly round in shape, and have cleared its orbit of other debris. This definition, however, excludes exoplanets and is considered vague by many in the scientific community. Dr. Margot and his team argue that a more quantitative approach is needed to accurately classify planets and satellites both within and beyond our solar system.
Their proposed definition classifies a planet as a celestial body that orbits one or more stars, brown dwarfs, or stellar remnants, is more massive than 10^23 kg, and less massive than 13 Jupiter masses. This definition, which focuses on the ability of a body to clear its zone within a specified timescale, aims to be more inclusive and applicable to exoplanets.
The researchers believe that their new definition will provide a better framework for identifying and characterizing exoplanets and their satellites, aiding in the exploration and understanding of the cosmos. They plan to resubmit their proposal for consideration by the IAU in advance of the 2027 General Assembly, hoping for a more positive outcome.
The study’s findings could potentially reclassify Pluto and other celestial bodies, sparking a renewed debate within the scientific community and beyond. Dr. Margot emphasizes that the focus should be on the ability to clear a zone rather than the state of having cleared it, making the new definition robust, quantifiable, and observable.
Summary
This new definition, if adopted, could revolutionize our understanding of planets and their classification. It would encompass a broader range of celestial bodies and provide a more precise, quantitative approach to defining planets, which could enhance our exploration and understanding of the universe.
For more detailed information and updates, refer to the official publication in The Planetary Science Journal and follow the developments from the IAU’s future General Assemblies.