Pluto, once considered the ninth planet in our solar system, is now classified as a dwarf planet. One of the most common questions about this celestial body is its size relative to Earth. This article explores the answer to that question – what is Pluto’s size compared to Earth?
A size comparison of Earth and Pluto. Pluto is significantly smaller than Earth.
Courtesy: NASA Visualization Technology Applications and Development (VTAD)
How Big is Pluto?
Pluto boasts an equatorial diameter of approximately 1,477 miles (2,377 kilometers). This makes Pluto roughly one-fifth the width of Earth. To put that into perspective, Pluto is only about half the width of the United States! Imagine trying to fit the entire dwarf planet within the continental US – it gives you a real sense of its diminutive size.
Pluto’s Size Compared to Earth’s Moon
Not only is Pluto significantly smaller than Earth, it’s even smaller than Earth’s moon. Earth’s moon has a diameter of 2,159 miles (3,475 kilometers), making it larger than Pluto by a considerable margin.
Pluto’s Distance from the Sun
Pluto’s small size isn’t its only distinguishing feature. It’s also incredibly far away. Located in the Kuiper Belt, a region beyond Neptune filled with icy bodies, Pluto resides at an average distance of 3.7 billion miles (5.9 billion kilometers) from the Sun. This is about 39 times farther than Earth’s distance from the Sun. Consequently, sunlight takes 5.5 hours to reach Pluto, compared to the mere 8 minutes it takes to reach Earth.
Black and white photo of a young girl with a spiral bun in her hair.
Venetia Burney, who suggested the name Pluto at age 11.
Courtesy: Venetia Burney
Why is Pluto a Dwarf Planet?
Pluto’s reclassification as a dwarf planet in 2006 by the International Astronomical Union (IAU) stemmed from the discovery of other similarly sized objects in the Kuiper Belt. The IAU defined a dwarf planet as a celestial body that orbits the Sun, is massive enough for its gravity to pull it into a nearly round shape, but has not cleared its orbital neighborhood of other objects. Because Pluto shares its orbital path with other celestial bodies in the Kuiper Belt, it doesn’t meet all the criteria for a full-fledged planet.
Exploring Pluto: The New Horizons Mission
Despite its small size and remote location, Pluto remains a fascinating object of study. In 2015, NASA’s New Horizons spacecraft provided the first close-up images of Pluto, revealing a surprisingly complex world with mountains, valleys, plains, craters, and even a possible subsurface ocean. This mission significantly enhanced our understanding of this distant dwarf planet and highlighted the diversity of objects within our solar system.
Conclusion
Pluto, while small compared to Earth, is a captivating celestial body. Its diminutive size, approximately one-fifth the width of Earth, and its unique characteristics make it a compelling subject for ongoing scientific exploration. The data collected by the New Horizons mission has revolutionized our understanding of Pluto, transforming it from a distant point of light to a complex world with its own geological and atmospheric processes. While no longer considered a planet, Pluto’s significance in our understanding of the solar system remains undeniable.
