Pluto: From Planet to Dwarf Planet – An Astronomical Story

Pluto: From Planet to Dwarf Planet – An Astronomical Story

In this video, I'm going to tell you about one of the most controversial celestial bodies in our solar system: Pluto. Its discovery, recognition as a planet, and eventual reclassification sparked intense debates in the world of astronomy. Let's start by addressing the fact that Pluto is no longer considered a planet, and here’s why.

Pluto was discovered in 1930 by American astronomer Clyde Tombaugh. Located about six billion kilometers from the Sun, Pluto was classified as the ninth planet of the solar system due to its orbit around the Sun and its distinct shape. At that time, the scientific community didn't have precise criteria for defining a planet, so Pluto retained its planetary status for many years.

Pluto stands out because of its small size and elliptical orbit. With a diameter of about 2,377 kilometers, Pluto is smaller than Earth’s Moon. In addition to its size, its orbit is also very different from those of the other planets in the solar system. These differences were initially overlooked given the knowledge and classification standards of the time. However, in 2006, the International Astronomical Union (IAU) agreed on a clear definition of what constitutes a planet. According to this new definition, a celestial body must meet three criteria to be considered a planet:

It must orbit the Sun.
It must have sufficient mass to assume a nearly round shape under its own gravity.
It must clear its orbit of other objects.
While Pluto meets the first two criteria, it failed to clear its orbit of other objects, leading to its demotion from the category of planets. Since then, Pluto has been reclassified as a dwarf planet.

Despite no longer being considered a planet, Pluto remains an important subject in space exploration. In 2015, NASA's New Horizons spacecraft visited Pluto, capturing detailed images of this distant celestial body. This mission provided new insights into Pluto’s surface features, atmosphere, and its moons. Pluto’s evolving status also highlights how quickly new scientific discoveries can be integrated into academic literature and reflected in education.

#pluto #solarsystem #astronomy