Scientists propose new definition of planets, Pluto still remains excluded

In short Simplifying... In short Scientists have proposed a new definition for planets, which includes celestial bodies orbiting any star, stellar remnant, or brown dwarf.

This definition, which emphasizes dynamic dominance, applies to planets both within and beyond our solar system.

However, Pluto, lacking this key characteristic, remains classified as a dwarf planet. Was a long read? Making it simpler... Next Article Next Article

The new definition will be presented at the IAU General Assembly in August

Scientists propose new definition of planets, Pluto still remains excluded

By Akash Pandey 11:40 am Jul 14, 202411:40 am

What's the story Planetary scientists are challenging the International Astronomical Union's 2006 definition of a planet. The current definition, which describes a planet as a celestial body orbiting the Sun in our solar system, is considered outdated and overly Sun-centric by many experts. Jean-Luc Margot, professor at the University of California and lead author of the proposal, states, "The current definition specifically mentions orbiting our sun...the IAU definition applies only to the ones in our solar system."

Expansion

Proposal expands definition beyond our solar system

The proposed definition, set to be published in the Planetary Science Journal, advocates for a broader understanding of planets. It includes celestial bodies beyond our solar system and introduces quantitative criteria to clarify what constitutes a planet. Margot explains, "We propose a new definition that can be applied to celestial bodies that orbit any star, stellar remnant, or brown dwarf."

Quantification

It includes quantifiable criterion for planets

The new proposal introduces a quantifiable criterion applicable to planets both inside and outside our solar system. Margot, along with co-authors Brett Gladman and Tony Yang, has developed a mathematical algorithm to understand how objects cluster together in the solar system. Margot notes, "All the planets in our solar system are dynamically dominant... So this property can be included in the definition of planet."

What's more?

Pluto remains excluded in new planetary definition

Despite the proposed changes to the definition of a planet, Pluto remains excluded. The new definition emphasizes dynamic dominance as the key characteristic of planets — a quality that dwarf planets like Pluto lack. This exclusion continues to uphold IAU's 2006 decision which reclassified Pluto as a dwarf planet. Margot will present the proposed new planetary definition at the IAU General Assembly in August 2024.