Why is Pluto not considered a planet anymore? Explained

Title: Why Pluto is No Longer Considered a Planet: An Explanation

Subtitle: The International Astronomical Union’s Decision and the Criteria for Planetary Classification

Date: June 21, 2023

Pluto, once considered the ninth planet in our solar system, is no longer categorized as a planet. Instead, it is now classified as a dwarf planet. This change in status was made by the International Astronomical Union (IAU) in August 2006. In this article, we will explore the reasons behind this decision and the criteria for planetary classification.

According to the IAU, a celestial body is considered

pluto planet

Pluto, once considered the ninth planet in our solar system, has undergone a change in classification. The International Astronomical Union (IAU) made the decision to reclassify Pluto as a dwarf planet in August 2006. This article aims to provide an explanation for why Pluto is no longer considered a planet, focusing on the IAU’s decision and the criteria they used for planetary classification.

Prior to its reclassification, Pluto was included as a planet in the traditional definition. However, advancements in astronomical research and observations led to a better understanding of our solar system, prompting the need for a more precise definition of what constitutes a planet.

The IAU, an internationally recognized authority in astronomy, convened in 2006 to address this issue and establish a clear set of criteria for planetary classification. One of the main reasons for reclassifying Pluto was the discovery of other celestial bodies in the Kuiper Belt, a region of the solar system beyond Neptune that contains many icy objects similar to Pluto.

The IAU’s criterion for a celestial body to be considered a planet is as follows:

1. It must orbit the Sun.

2. It must have sufficient mass to assume a nearly round shape due to its own gravity.

3. It must have cleared its orbit of other debris.

Pluto failed to meet the third criterion, as it shares its orbit with other objects in the Kuiper Belt. This led to the conclusion that Pluto should be classified as a dwarf planet rather than a full-fledged planet. A dwarf planet is defined as a celestial body that meets the first two criteria but has not cleared its orbit.

By reclassifying Pluto as a dwarf planet, the IAU aimed to establish a precise and scientific definition of what constitutes a planet. This decision was supported by the majority of astronomers and has brought clarity to the classification of celestial bodies in our solar system.

In conclusion, Pluto is no longer considered a planet but rather a dwarf planet according to the IAU’s decision made in 2006. The IAU established criteria for planetary classification, and Pluto’s failure to clear its orbit led to its reclassification. This change reflects the advancement of our understanding of the solar system and ensures a more accurate classification of celestial bodies.