Pluto
Pluto — the pale heart of nitrogen ice (Tombaugh Regio) revealed by New Horizons in 2015. Procedural illustration.
The Famous Dwarf Planet
Diameter
2,377 km
Smaller than our Moon
Day length
6.4 days
Tilted like Uranus
Year
248 years
Since discovery, <1 orbit
Pluto was the ninth planet from its discovery in 1930 until 2006, when it was reclassified as a dwarf planet — one of the largest members of the Kuiper Belt. In 2015 NASA’s New Horizons flew past and transformed it from a fuzzy dot into a world: nitrogen-ice glaciers, water-ice mountains, and a vast pale heart-shaped plain now called Tombaugh Regio.
Finding It
At magnitude 14 Pluto is far beyond naked-eye, binocular, or small-telescope reach — spotting it takes at least an 8-inch telescope, a dark sky like Zion’s, and a detailed finder chart, and even then it is just a faint point that you confirm by watching it shift against the stars over several nights. It is a target you hunt rather than simply see.