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
Liquid nitrogen may have flowed on Pluto’s surface in recent past
August 9, 2026
Liquid nitrogen may still be seeping up beneath the dwarf planet’s giant glacier, Sputnik Planitia. Read more
Pluto’s thin atmosphere may be starting to shrink
August 4, 2026
Pluto’s tenuous atmosphere appears to have begun contracting after years of holding steady. Read more
Scientists discover mystery molecule on Pluto and Saturn's moon Titan
July 20, 2026
'We cannot say what it is' Read more
Astronomers discover landslides on Pluto large enough to bury entire cities on Earth
July 16, 2026
The great lengths that the debris rolled means that Pluto's landslides are among the most mobile in the solar system. Read more
The spin of Pluto's moon, Charon, may be slowing down
July 14, 2026
Evidence of Charon's slowing spin period (despinning) is recorded in tectonic features on the surface of Pluto's icy moon. Read more
NASA’s New Horizons spacecraft wakes from hibernation in good health
July 7, 2026
Following its longest hibernation period ever of nearly a year, New Horizons is ready to begin transmitting science data gathered in the distant Kuiper Belt. Read more
A small object past Pluto may have a thin atmosphere
May 4, 2026
The possible atmosphere around 2002 XV93 would be a first for a small object beyond Pluto. Read more
Potentially distinct structure in Kuiper belt discovered with help of clustering algorithm
November 21, 2025
A newly identified region appears to be completely distinct from other parts of the belt. Read more
Signs of late-stage cryovolcanism in Pluto’s Hayabusa Terra
October 19, 2025
The new study helps scientists better understand the current geological activity, including how it can be active while orbiting so far from the Sun. Read more
Interstellar comet 3I/ATLAS will be eyed by Mars and Jupiter probes
October 2, 2025
Observing it in this active phase will give some of the clearest insights yet into the mystery of interstellar comets. Read more
The weird ringed dwarf planet Quaoar may have an extra moon
September 10, 2025
"The profile of the occultation was most consistent with it being a new satellite — a new moon — going around Quaoar." Read more
JWST detects methane gas on dwarf planet Makemake
September 9, 2025
This discovery makes it only the second trans-Neptunian object with a confirmed presence of gas Read more
1st known interstellar visitor 'Oumuamua is an 'exo-Pluto' — a completely new class of object, scientists say
September 8, 2025
"'Oumuamua is in a different category of object. It's much harder to find, but there are a lot more of them." Read more
Pluto's dwarf planet partner Charon may have spilled its guts to create 2 of the pair's moons
September 1, 2025
"The surfaces of Nix and Hydra are as close to unaltered as you can get." Read more
An icy supervolcano eruption on Pluto may have left a massive crater on the frozen world
August 6, 2025
The caldera may have blasted out its cryomagma in a single explosive event, or over time Read more
Cryovolcanism and resurfacing on Pluto's largest moon, Charon
June 27, 2025
A recent study hopes to determine whether it once possessed an internal ocean Read more
JWST confirms cooling effects of Pluto’s haze
June 2, 2025
New study in Nature Astronomy affirms hypothesis made by UC Santa Cruz’s Xi Zhang in 2017 Read more
Does our solar system have a new dwarf planet?
May 23, 2025
The recently discovered object has a diameter about one-third that of Pluto Read more
Hubble discovers a new '3-body problem' puzzle among Kuiper Belt
March 5, 2025
The universe is filled them, and we're finding that the Kuiper Belt may be no exception! Read more
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
SwRI models Pluto-Charon formation scenario that mimics Earth-Moon system
January 7, 2025
New findings could support Pluto’s geologic activity and potential subsurface ocean Read more
How Pluto captured its largest moon Charon with a 10-hour icy 'kiss'
January 6, 2025
"We were definitely surprised by the 'kiss' part of kiss-and-capture" Read more
JWST reveals surprising surface chemistry is occurring on Pluto’s moon Charon
December 31, 2024
Both carbon dioxide and hydrogen peroxide on the surface of this distant moon Read more
Revised solar system chemistry explains long-standing puzzles
November 20, 2024
Astronomers say they have figured out the true chemical makeup of our solar system Read more
James Webb Space Telescope deciphers the origins of Pluto's icy moon Charon
October 1, 2024
Detecting certain molecules could tell scientists how Charon and other icy bodies at the solar system's edge were born. 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