How Is Pluto Still Active?
The New Horizons spacecraft sent back images from its 2015 flyby of Pluto showing clear evidence for recent and ongoing geologic activity. But how is this possible on such a tiny world so far from the Sun? Deep in the dwarf planet’s core, radioactive elements decaying over the eons continue to heat the interior enough to maintain a subsurface layer of liquid water that can push on and shift the crust above. This causes polygonal cracks the surface, builds mountain ranges, and creates icy volcanoes with watery lava. Similar processes driven by internal radioactivity are happening on rocky planets and large moons, though for some, like Earth, the liquid layer is made of molten rock, not water. On the surface, interactions between ices on the ground, the atmosphere, and sunlight produce a frigid climate that creates active glaciers of nitrogen ice and shifting dunes made of methane snow, erasing many small recent craters. Read More
Latest News About Pluto and The Kuiper Belt
New Horizons probe gearing up for epic crossing of 'termination shock'
February 19, 2025
"The data from the termination shock encounter will be a treasure trove for space physicists worldwide" Read more
Is Pluto a planet or not? Who cares!
February 18, 2025
Our love for the King of the Kuiper Belt is stronger than ever 95 years later Read more
![Images of the trans-Neptunian objects (TNOs) Pluto [left] and Arrokoth [right], the primary flyby targets of NASA’s New Horizons spacecraft in 2015 and 2019](https://saganplanetwalk.com/wp-content/themes/saganplanetwalk2018/img/Pluto_021425_unexpected.jpg "Images of the trans-Neptunian objects (TNOs) Pluto [left] and Arrokoth [right], the primary flyby targets of NASA’s New Horizons spacecraft in 2015 and 2019")
NASA’s JWST just found something unexpected beyond Neptune
February 14, 2025
JWST has provided the first high-resolution spectral data on TNOs Read more
Fascinating Facts About Pluto
- If the sun were as tall as a typical front door, Earth would be the size of a nickel and dwarf planet Pluto would be about the size of the head of a pin.
- Sunlight on Pluto has the same intensity as moonlight on Earth.
- Pluto and its largest moon Charon form a binary system and orbit around a center of mass that is outside Pluto; it is the only binary system we have directly observed.
- Pluto’s name was proposed by an eleven-year-old girl named Venetia Burney from Oxford, England in 1930.
- The discovery of Eris in the Kuiper Belt led to Pluto’s demotion from planet to dwarf planet; similarly, Ceres in the asteroid belt was reclassified as a dwarf planet.
- The Kuiper Belt is where short-period comets (which take less than 200 years to orbit the Sun) originate.
- Some dwarf planets, such as Pluto, have thin atmospheres that collapse when they are farthest from the Sun in their orbits.
- Several dwarf planets in the Kuiper belt have moons; Pluto has five moons.
Missions
New Horizons (2006)
Mission to study Pluto, its moons and other Kuiper Belt objects