Pluto is a dwarf planet in the Kuiper belt, a ring of bodies beyond the orbit of Neptune. It is the ninth-largest and tenth-most-massive known object to directly orbit the Sun. It is the largest known trans-Neptunian object by volume, by a small margin, but is less massive than Eris. Like other Kuiper belt objects, Pluto is made primarily of ice and rock and is much smaller than the inner planets. Pluto has roughly one-sixth the mass of the Moon, and one-third its volume.
The geology of Pluto consists of the characteristics of the surface, crust, and interior of Pluto. Because of Pluto's distance from Earth, in-depth study from Earth is difficult. Many details about Pluto remained unknown until 14 July 2015, when New Horizons flew through the Pluto system and began transmitting data back to Earth. When it did, Pluto was found to have remarkable geologic diversity, with New Horizons team member Jeff Moore saying that it "is every bit as complex as that of Mars". The final New Horizons Pluto data transmission was received on 25 October 2016. In June 2020, astronomers reported evidence that Pluto may have had a subsurface ocean, and consequently may have been habitable, when it was first formed.
Krun or Akrun is a Mandaean lord of the underworld. According to Mandaean cosmology, he dwells in the lowest depths of creation, supporting the entirety of the physical world.
The exploration of Pluto began with the arrival of the New Horizons probe in July 2015, though proposals for such a mission had been studied for many decades. There are no plans as yet for a follow-up mission, though follow-up concepts have been studied.
Tombaugh Regio, sometimes nicknamed "Pluto's heart" after its shape, is the largest bright surface feature of the dwarf planet Pluto. It lies just north of Pluto's equator, to the northeast of Belton Regio and to the northwest of Safronov Regio, which are both dark features. Its western lobe, a 1,000 km (620 mi)-wide plain of nitrogen and other ices lying within a basin, is named Sputnik Planitia. The eastern lobe consists of high-albedo uplands thought to be coated by nitrogen transported through the atmosphere from Sputnik Planitia, and then deposited as ice. Some of this nitrogen ice then returns to Sputnik Planitia via glacial flow. The region is named after Clyde Tombaugh, the discoverer of Pluto.
Belton Regio is a prominent surface feature of the dwarf planet Pluto. It is an elongated dark region along Pluto's equator, 2,990 km (1,860 mi) long and one of the darkest features on its surface.
The Tenzing Montes are a range of icy mountains on Pluto, bordering the southwest region of Sputnik Planitia and the nearby Hillary Montes and Wright Mons. With peaks reaching 6.2 km in height, they are the highest mountain range on Pluto, and also the steepest, with a mean slope of 19.2 degrees.
Sputnik Planitia is a large, partially glaciated basin on Pluto. About 1,400 by 1,200 km in size, Sputnik Planitia is partially submerged in large, bright glaciers of nitrogen ice. Named after Earth's first artificial satellite, Sputnik 1, it constitutes the western lobe of the heart-shaped Tombaugh Regio. Sputnik Planitia lies mostly in the northern hemisphere, but extends across the equator. Much of it has a surface of irregular polygons separated by troughs, interpreted as convection cells in the relatively soft nitrogen ice. The polygons average about 33 km (21 mi) across. In some cases troughs are populated by blocky mountains or hills, or contain darker material. There appear to be windstreaks on the surface with evidence of sublimation. The dark streaks are a few kilometers long and all aligned in the same direction. The planitia also contains pits apparently formed by sublimation. No craters were detectable by New Horizons, implying a surface less than 10 million years old. Modeling sublimation pit formation yields a surface age estimate of 180000+90000
−40000 years. Near the northwest margin is a field of transverse dunes, spaced about 0.4 to 1 km apart, that are thought to be composed of 200-300 μm diameter particles of methane ice derived from the nearby Al-Idrisi Montes.
Vucub-Came Macula is one of the "Brass Knuckles", a series of equatorial dark regions on Pluto. It is named after Wuquub' Kameh "Seven Death", one of the Quiché death gods in the Popol Vuh.
Hun-Came Macula is one of the "Brass Knuckles", a series of equatorial dark regions on Pluto. It is named after Jun Kameh "One Death", one of the Quiché death gods in the Popol Vuh.
Meng-pʻo Macula is the easternmost of the "Brass Knuckles", a series of equatorial dark regions on Pluto. Meng-pʻo straddles the zero meridian, directly under Pluto's tidally locked moon Charon and just west of the tail of the "Whale", Belton Regio. It is named after Meng Po, the Chinese underworld deity of forgetfulness.
The Hillary Montes or are a mountain range that reach 3.5 km above the surface of the dwarf planet Pluto. They are located northwest of Tenzing Montes in the southwest border area of Sputnik Planitia in the south of Tombaugh Regio. The Hillary Montes were first viewed by the New Horizons spacecraft on 14 July 2015, and announced by NASA on 24 July 2015.
Morgoth Macula is the informal name for a small dark region on the surface of Pluto, southwest of the Norgay Montes and adjacent to Sputnik Planitia. It was discovered in 2015 by the spacecraft New Horizons and named after Morgoth, the primary antagonist in J.R.R. Tolkien's legendarium.
Cadejo Macula is a small dark surface feature on Pluto near Voyager Terra. It is unofficially named after El Cadejo, a hellish spirit from Central American folklore which appears in the form of a large dog-like creature with burning red eyes. The feature was photographed by the New Horizons probe during the July 2015 flyby of the dwarf planet.
Baret Montes is a chain of mountains on the surface of the dwarf planet Pluto. It is located near the western border of Sputnik Planitia in Tombaugh Regio. These mountains were first viewed by the New Horizons spacecraft. It features large ridges that are formed by the compression of methane and water ice.
Safronov Regio is the westernmost of the "Brass Knuckles", a series of equatorial dark regions on Pluto.
Piccard Mons is a large, roughly circular mountain and likely cryovolcano on the dwarf planet Pluto. Discovered by the New Horizons spacecraft in 2015, it is located southeast of Wright Mons within the Tombaugh Regio, adjacent to the Safronov Regio and Elcano Montes.
Harrington Regio is the largest of the "Brass Knuckles", a series of equatorial dark regions on Pluto.
Sharaf Regio is the smallest of the "Brass Knuckles", a series of equatorial dark regions on Pluto. It was initially informally named Ala Macula after Ala "earth", the chthonic and most important deity of the Igbo people. The International Astronomical Union (IAU) officially approved the name Sharaf Regio after Shafika Gil’mievna Sharaf, a Soviet astronomer who developed an analytical theory for Pluto's motion.