Pluto was discovered on February 18, 1930, by astronomer Clyde Tombaugh at the Lowell Observatory in Flagstaff, Arizona. Initially, it was named Planet X, but later the name Pluto was suggested by an 11-year-old girl named Venetia Burney.
The name was inspired by the Roman god of the underworld.
Pluto, once considered the ninth planet in our solar system, was reclassified in 2006 by the International Astronomical Union (IAU) as a dwarf planet. But why exactly is Pluto no longer classified as a planet?
Look stellar in one of our premium, 100% cotton science tees.
Size Matters
One of the main reasons Pluto was demoted from planet status is its size. While the eight planets in our solar system dominate in size, Pluto is significantly smaller. In fact, it is even smaller than Earth's moon. Its size, along with its irregular orbit, led to its reclassification.
Pluto is significantly smaller than Earth, with a diameter of approximately 1,473 miles (2,370 kilometers). This makes Pluto only about 18.5% the size of Earth. In terms of mass, Pluto is much lighter than Earth, weighing in at only 0.2% of Earth's mass.
As a dwarf planet, Pluto is not the smallest object in our solar system. In fact, there are several moons, such as Saturn's moon Enceladus, that are smaller than Pluto.
Pluto is the largest known dwarf planet in our solar system. However, there are other dwarf planets, such as Eris and Haumea, that are comparable in size to Pluto. Eris, for example, is slightly smaller than Pluto, with a diameter of about 1,445 miles (2,326 kilometers).
Studying the size of Pluto and other celestial bodies can provide valuable insights into the formation and evolution of our solar system. By understanding the size and composition of objects like Pluto, scientists can piece together the history of our cosmic neighborhood and gain a better understanding of the universe as a whole.
While Pluto may no longer hold the title of the ninth planet, its size and characteristics continue to intrigue scientists and stargazers alike. By delving into the specifics of Pluto's size, we can uncover a wealth of knowledge about the vast and mysterious cosmos beyond our own planet.
Unlike the eight planets, Pluto's orbit is not cleared of other debris. It shares its orbit with other objects in the Kuiper Belt, a region beyond Neptune filled with icy bodies. This lack of orbital dominance is another factor that contributed to Pluto's reclassification.
Composition
Pluto is primarily composed of rock and ice, with a rocky core surrounded by a mantle of water ice and other ices such as methane and nitrogen. These ices give Pluto its distinctive appearance, with a surface that is a mix of frozen plains, mountains, and valleys.
Compared to the gas giants like Jupiter and Saturn, Pluto is much smaller and less massive. Its composition is more similar to that of the icy moons of the outer solar system, such as Triton and Europa. However, Pluto's unique combination of rock and ice sets it apart as a dwarf planet (not an actual planet.)
Studying Pluto's composition can provide valuable insights into the formation and evolution of the outer solar system. By analyzing the different ices and rocks present on Pluto, scientists can learn more about the conditions that existed in the early solar system and how planets and dwarf planets like Pluto came to be.
In 2015, NASA's New Horizons spacecraft made a historic flyby of Pluto, providing unprecedented close-up images and data about the dwarf planet. The mission revealed a diverse and complex surface, with evidence of geological activity and a dynamic environment. These findings have deepened our understanding of Pluto's composition and its place in the solar system.
As scientists continue to study Pluto and other objects in the outer solar system, we can expect to uncover even more secrets about the composition and history of these distant worlds. Pluto may be small, but its composition holds big clues about the mysteries of our solar system.
Not Unique
Pluto is not the only object in the solar system that shares characteristics with it. There are other similar objects in the Kuiper Belt that are comparable in size and composition to Pluto. This lack of uniqueness also played a role in the decision to reclassify Pluto.
While Pluto may have once held a special place in our hearts as the ninth planet in our solar system, scientific research has revealed that it is not as unique as we once believed. As a member of the Kuiper Belt and a dwarf planet, Pluto shares many characteristics with other icy bodies in our cosmic neighborhood. By studying Pluto and its fellow dwarf planets, scientists continue to unravel the mysteries of our solar system and the universe beyond.
In conclusion, the reclassification of Pluto as a dwarf planet was based on scientific evidence and a reevaluation of what defines a planet in our solar system. While Pluto may not be considered a planet anymore, it continues to intrigue scientists and astronomers alike as we continue to explore the vast wonders of our solar system.
Thanks for stopping by! Before you go, check out our awesome Space Trivia Questions!
