The internal structure of Earth
William Lassell, the discoverer of Triton
The orbit of Triton (red) is opposite in direction and tilted −23° compared to a typical moon's orbit (green) in the plane of Neptune's equator.
Animation of Triton
The Kuiper belt (green), in the Solar System's outskirts, is where Triton is thought to have originated.
Artist's impression of Triton, showing its tenuous atmosphere just over the limb.
Clouds observed above Triton's limb by Voyager 2.
Interpretative geomorphological map of Triton
Triton's bright south polar cap above a region of cantaloupe terrain
Cantaloupe terrain viewed from 130,000 km by Voyager 2, with crosscutting Europa-like double ridges. Slidr Sulci (vertical) and Tano Sulci form the prominent "X".
Tuonela Planitia (left) and Ruach Planitia (center) are two of Triton's cryovolcanic "walled plains". The paucity of craters is evidence of extensive, relatively recent, geologic activity.
NASA illustration detailing the studies of the proposed Trident mission
Neptune (top) and Triton (bottom) three days after flyby of Voyager 2
thumb|Close up of the volcanic province of Leviathan Patera, the caldera in the center of the image. Several pit chains extend radially from the caldera to the right of the image, while the smaller of the two cryolava lakes is seen to the upper left. Just off-screen to the lower left is a fault zone aligned radially with the caldera, indicating a close connection between the tectonics and volcanology of this geologic unit.
thumb|Dark streaks across Triton's south polar cap surface, thought to be dust deposits left by eruptions of nitrogen geysers
thumb|Two large cryolava lakes on Triton, seen west of Leviathan Patera. Combined, they are nearly the size of Kraken Mare on Titan. These features are unusually crater free, indicating they are young and were recently molten.

Triton has a surface of mostly frozen nitrogen, a mostly water-ice crust, an icy mantle and a substantial core of rock and metal.

- Triton (moon)

Titan and Triton each have a mantle made of ice or other solid volatile substances.

- Mantle (geology)
The internal structure of Earth

1 related topic

Alpha

Europa's trailing hemisphere in approximate natural colour. The prominent crater in the lower right is Pwyll and the darker regions are areas where Europa's primarily water ice surface has a higher mineral content. Imaged on 7 September 1996 by Galileo spacecraft.

Europa (moon)

Smallest of the four Galilean moons orbiting Jupiter, and the sixth-closest to the planet of all the 80 known moons of Jupiter.

Smallest of the four Galilean moons orbiting Jupiter, and the sixth-closest to the planet of all the 80 known moons of Jupiter.

Europa's trailing hemisphere in approximate natural colour. The prominent crater in the lower right is Pwyll and the darker regions are areas where Europa's primarily water ice surface has a higher mineral content. Imaged on 7 September 1996 by Galileo spacecraft.
Animation of the Laplace resonance of Io, Europa and Ganymede (conjunctions are highlighted by color changes)
Size comparison of Europa (lower left) with the Moon (top left) and Earth (right)
Approximate natural color (left) and enhanced color (right) Galileo view of leading hemisphere
Realistic-color Galileo mosaic of Europa's anti-Jovian hemisphere showing numerous lineae
Enhanced-color view showing the intricate pattern of linear fractures on Europa's surface
Two possible models of Europa
Europa - internal structure
(artwork; 25 May 2021)
Closeup views of Europa obtained on 26 September 1998; images clockwise from upper left show locations from north to south as indicated at lower left.
Water plumes on Europa detected by the Galileo space probe
Photo composite of suspected water plumes on Europa
Magnetic field around Europa. The red line shows a trajectory of the Galileo spacecraft during a typical flyby (E4 or E14).
A black smoker in the Atlantic Ocean. Driven by geothermal energy, this and other types of hydrothermal vents create chemical disequilibria that can provide energy sources for life.
Europa – possible effect of radiation on biosignature chemicals

Europa is one of the only moons in our solar system with a quantifiable atmosphere, next to Titan, Io, and Triton.

The likely presence of liquid water in contact with Europa's rocky mantle has spurred calls to send a probe there.