Pluto's Surface Area Is About the Same as Russia's

It’s a startling exercise in scale to imagine unpeeling the entire surface of Pluto and laying it flat. That vast, icy expanse would cover an area just slightly larger than the nation of Russia, a comparison that powerfully grounds a distant celestial body to a familiar terrestrial scale. This diminutive size is a key reason Pluto's status has been so debated. For perspective, its diameter is less than two-thirds that of Earth's own Moon, making it a truly small world wandering the frigid, outer edges of our solar system.

Pluto’s small stature is central to its famous reclassification from a planet to a dwarf planet. In 2006, the International Astronomical Union established a new definition for a planet, which included the criterion that it must have "cleared the neighborhood" around its orbit. Because Pluto is located in the Kuiper Belt, a crowded region of icy objects, it hasn't gravitationally dominated its orbital zone. The discovery of other Kuiper Belt objects, some of comparable size to Pluto, prompted this reevaluation. Our precise understanding of its size was only confirmed in 2015 by the New Horizons spacecraft, which provided the first-ever close-up images and data of this fascinating, complex world.