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Io (moon)

Io, or Jupiter I, is the innermost and second-smallest of the four Galilean moons of the planet Jupiter. Slightly larger than Earth's moon, Io is the fourth-largest moon in the Solar System, has the highest density of any moon, the strongest surface gravity of any moon, and the lowest amount of water by atomic ratio of any known astronomical object in the Solar System. It was discovered in 1610 by Galileo Galilei and was named after the mythological character Io, a priestess of Hera who became one of Zeus's lovers.

With over 400 active volcanoes, Io is the most geologically active object in the Solar System. This extreme geologic activity is the result of tidal heating from friction generated within Io's interior as it is pulled between Jupiter and the other Galilean moons—Europa, Ganymede and Callisto. Several volcanoes produce plumes of sulfur and sulfur dioxide that climb as high as 500 km above the surface. Io's surface is also dotted with more than 100 mountains that have been uplifted by extensive compression at the base of Io's silicate crust. Some of these peaks are taller than Mount Everest, the highest point on Earth's surface. Unlike most moons in the outer Solar System, which are mostly composed of water ice, Io is primarily composed of silicate rock surrounding a molten iron or iron sulfide core. Most of Io's surface is composed of extensive plains with a frosty coating of sulfur and sulfur dioxide.

Io's volcanism is responsible for many of its unique features. Its volcanic plumes and lava flows produce large surface changes and paint the surface in various subtle shades of yellow, red, white, black, and green, largely due to allotropes and compounds of sulfur. Numerous extensive lava flows, several more than 500 km in length, also mark the surface. The materials produced by this volcanism make up Io's thin, patchy atmosphere, and they also greatly affect the nature and radiation levels of Jupiter's extensive magnetosphere. Io's volcanic ejecta also produce a large, intense plasma torus around Jupiter, creating a hostile radiation environment on and around the moon; Io receives about 3,600 rem (36 Sv) of ionizing radiation per day.

Io played a significant role in the development of astronomy in the 17th and 18th centuries; discovered in January 1610 by Galileo Galilei, along with the other Galilean satellites, this discovery furthered the adoption of the Copernican model of the Solar System, the development of Kepler's laws of motion, and the first measurement of the speed of light. In 1979, the two Voyager spacecraft revealed Io to be a geologically active world, with numerous volcanic features, large mountains, and a young surface with no obvious impact craters. The Galileo spacecraft performed several close flybys in the 1990s and early 2000s, obtaining data about Io's interior structure and surface composition. These spacecraft also revealed the relationship between Io and Jupiter's magnetosphere and the existence of a belt of high-energy radiation centered on Io's orbit. Further observations have been made by Cassini–Huygens in 2000, New Horizons in 2007, and Juno since 2017, as well as from Earth-based telescopes and the Hubble Space Telescope.

Nomenclature

Although Simon Marius is not credited with the sole discovery of the Galilean satellites, his names for the moons were adopted. In his 1614 publication Mundus Iovialis anno M.DC.IX Detectus Ope Perspicilli Belgici, he proposed several alternative names for the innermost of the large moons of Jupiter, including "The Mercury of Jupiter" and "The First of the Jovian Planets". Based on a suggestion from Johannes Kepler in October 1613, he also devised a naming scheme whereby each moon was named for a lover of the Greek god Zeus or his Roman equivalent, Jupiter. He named the innermost large moon of Jupiter after the Greek Io:

"Jupiter is much blamed by the poets on account of his irregular loves. Three maidens are especially mentioned as having been clandestinely courted by Jupiter with success. Io, daughter of the River Inachus, Callisto of Lycaon, Europa of Agenor. Then there was Ganymede, the handsome son of King Tros, whom Jupiter, having taken the form of an eagle, transported to heaven on his back, as poets fabulously tell... I think, therefore, that I shall not have done amiss if the First is called by me Io, the Second Europa, the Third, on account of its majesty of light, Ganymede, the Fourth Callisto..."

Marius's names were not widely adopted until centuries later (mid-20th century). In much of the earlier astronomical literature, Io was generally referred to by its Roman numeral designation (a system introduced by Galileo) as "Jupiter I", or as "the first satellite of Jupiter".

The customary English pronunciation of the name is, though sometimes people attempt a more 'authentic' pronunciation,. The name has two competing stems in Latin: Īō and (rarely) Īōn. The latter is the basis of the English adjectival form, Ionian.

Features on Io are named after characters and places from the Io myth, as well as deities of fire, volcanoes, the Sun, and thunder from various myths, and characters and places from Dante's Inferno: names appropriate to the volcanic nature of the surface. Since the surface was first seen up close by Voyager 1, the International Astronomical Union has approved 249 names for Io's volcanoes, mountains, plateaus, and large albedo features. The approved feature categories used for Io for different types of volcanic features include patera ('saucer'; volcanic depression), fluctus ('flow'; lava flow), vallis ('valley'; lava channel), and active eruptive center (location where plume activity was the first sign of volcanic activity at a particular volcano). Named mountains, plateaus, layered terrain, and shield volcanoes include the terms mons, mensa ('table'), planum, and tholus ('rotunda'), respectively. Named, bright albedo regions use the term regio. Examples of named features are Prometheus, Pan Mensa, Tvashtar Paterae, and Tsũi Goab Fluctus.

Observational history
The first reported observation of Io was made by Galileo Galilei on 7 January 1610 using a 20x-power, refracting telescope at the University of Padua. However, in that observation, Galileo could not separate Io and Europa due to the low power of his telescope, so the two were recorded as a single point of light. Io and Europa were seen for the first time as separate bodies during Galileo's observations of the Jovian system the following day, 8 January 1610 (used as the discovery date for Io by the IAU). The discovery of Io and the other Galilean satellites of Jupiter was published in Galileo's Sidereus Nuncius in March 1610. In his Mundus Jovialis, published in 1614, Simon Marius claimed to have discovered Io and the other moons of Jupiter in 1609, one week before Galileo's discovery. Galileo doubted this claim and dismissed the work of Marius as plagiarism. Regardless, Marius's first recorded observation came from 29 December 1609 in the Julian calendar, which equates to 8 January 1610 in the Gregorian calendar, which Galileo used. Given that Galileo published his work before Marius, Galileo is credited with the discovery.

For the next two and a half centuries, Io remained an unresolved, 5th-magnitude point of light in astronomers' telescopes. During the 17th century, Io and the other Galilean satellites served a variety of purposes, including early methods to determine longitude, validating Kepler's third law of planetary motion, and determining the time required for light to travel between Jupiter and Earth. Based on ephemerides produced by astronomer Giovanni Cassini and others, Pierre-Simon Laplace created a mathematical theory to explain the resonant orbits of Io, Europa, and Ganymede. This resonance was later found to have a profound effect on the geologies of the three moons.

Improved telescope technology in the late 19th and 20th centuries allowed astronomers to resolve (that is, see as distinct objects) large-scale surface features on Io. In the 1890s, Edward E. Barnard was the first to observe variations in Io's brightness between its equatorial and polar regions, correctly determining that this was due to differences in color and albedo between the two regions and not due to Io being egg-shaped, as proposed at the time by fellow astronomer William Pickering, or two separate objects, as initially proposed by Barnard. Later telescopic observations confirmed Io's distinct reddish-brown polar regions and yellow-white equatorial band.

Telescopic observations in the mid-20th century began to hint at Io's unusual nature. Spectroscopic observations suggested that Io's surface was devoid of water ice (a substance found to be plentiful on the other Galilean satellites). The same observations suggested a surface dominated by evaporates composed of sodium salts and sulfur. Radiotelescopic observations revealed Io's influence on the Jovian magnetosphere, as demonstrated by decametric wavelength bursts tied to the orbital period of Io.

Pioneer
The first spacecraft to pass by Io were the Pioneer 10 and 11 probes on 3 December 1973 and 2 December 1974, respectively. Radio tracking provided an improved estimate of Io's mass, which, along with the best available information of its size, suggested it had the highest density of the Galilean satellites, and was composed primarily of silicate rock rather than water ice. The Pioneers also revealed the presence of a thin atmosphere and intense radiation belts near the orbit of Io. The camera on board Pioneer 11 took the only good image of the moon obtained by either spacecraft, showing its north polar region and its yellow tint. Close-up images were planned during Pioneer 10's encounter, but those were lost because of the high-radiation environment.

Voyager
When the twin probes Voyager 1 and Voyager 2 passed by Io in 1979, their more advanced imaging systems allowed for far more detailed images. Voyager 1 flew past Io on 5 March 1979 from a distance of 20600 km. The images returned during the approach revealed a strange, multi-colored landscape devoid of impact craters. The highest-resolution images showed a relatively young surface punctuated by oddly shaped pits, mountains taller than Mount Everest, and features resembling volcanic lava flows.

Shortly after the encounter, Voyager navigation engineer Linda A. Morabito noticed a plume emanating from the surface in one of the images. Analysis of other Voyager 1 images showed nine such plumes scattered across the surface, proving that Io was volcanically active. This conclusion was predicted in a paper published shortly before the Voyager 1 encounter by Stan Peale, Patrick Cassen, and R. T. Reynolds. The authors calculated that Io's interior must experience significant tidal heating caused by its orbital resonance with Europa and Ganymede (see the "Tidal heating" section for a more detailed explanation of the process). Data from this flyby showed that the surface of Io is dominated by sulfur and sulfur dioxide frosts. These compounds also dominate its thin atmosphere and the torus of plasma centered on Io's orbit (also discovered by Voyager).

Voyager 2 passed Io on 9 July 1979 at a distance of 1130000 km. Though it did not approach nearly as close as Voyager 1, comparisons between images taken by the two spacecraft showed several surface changes that had occurred in the four months between the encounters. In addition, observations of Io as a crescent as Voyager 2 departed the Jovian system revealed that seven of the nine plumes observed in March were still active in July 1979, with only the volcano Pele shutting down between flybys.

Galileo

The Galileo spacecraft arrived at Jupiter in 1995 after a six-year journey from Earth to follow up on the discoveries of the two Voyager probes and the ground-based observations made in the intervening years. Io's location within one of Jupiter's most intense radiation belts precluded a prolonged close flyby, but Galileo did pass close by shortly before entering orbit for its two-year, primary mission studying the Jovian system. Although no images were taken during the close flyby on 7 December 1995, the encounter did yield significant results, such as the discovery of a large iron core, similar to that found on the rocky planets of the inner Solar System.

Despite the lack of close-up imaging and mechanical problems that greatly restricted the amount of data returned, several significant discoveries were made during Galileo primary mission. Galileo observed the effects of a major eruption at Pillan Patera and confirmed that volcanic eruptions are composed of silicate magmas with magnesium-rich mafic and ultramafic compositions. Distant imaging of Io was acquired for almost every orbit during the primary mission, revealing large numbers of active volcanoes (both thermal emission from cooling magma on the surface and volcanic plumes), numerous mountains with widely varying morphologies, and several surface changes that had taken place both between the Voyager and Galileo eras and between Galileo orbits.

The Galileo mission was twice extended, in 1997 and 2000. During these extended missions, the probe flew by Io three times in late 1999 and early 2000, and three times in late 2001 and early 2002. Observations during these encounters revealed the geologic processes occurring at Io's volcanoes and mountains, excluded the presence of a magnetic field, and demonstrated the extent of volcanic activity.

Cassini
In December 2000, the Cassini spacecraft had a distant and brief encounter with the Jovian system en route to Saturn, allowing for joint observations with Galileo. These observations revealed a new plume at Tvashtar Paterae and provided insights into Io's aurorae.

New Horizons
The New Horizons spacecraft, en route to Pluto and the Kuiper belt, flew by the Jovian system and Io on 28 February 2007. During the encounter, numerous distant observations of Io were obtained. These included images of a large plume at Tvashtar, providing the first detailed observations of the largest class of Ionian volcanic plume since observations of Pele's plume in 1979. New Horizons also captured images of a volcano near Girru Patera in the early stages of an eruption, and several volcanic eruptions that have occurred since Galileo.

Juno
The Juno spacecraft was launched in 2011 and entered orbit around Jupiter on July 5, 2016. Juno's mission is primarily focused on improving our understanding of Jupiter's interior, magnetic field, aurorae, and polar atmosphere. Juno's 54-day orbit is highly inclined and highly eccentric in order to better characterize Jupiter's polar regions and to limit its exposure to the planet's harsh inner radiation belts, limiting close encounters with Jupiter's moons. The closest approach to Io during the initial, prime mission occurred in February 2020 at a distance of 195,000 kilomters. Juno's extended mission, begun in June 2021, allowed for closer encounters with Jupiter's Galilean satellites due to Juno's orbital precession. After a series of increasingly closer encounters with Io in 2022 and 2023, Juno performed a pair of close flybys on December 30, 2023, and February 3, 2024, both with altitudes of 1,500 kilometers. The primary goal of these encounters were to improve our understanding of Io's gravity field using doppler tracking and to image Io's surface to look for surface changes since Io was last seen up-close in 2007.

During several orbits, Juno has observed Io from a distance using JunoCAM, a wide-angle, visible-light camera, to look for volcanic plumes and JIRAM, a near-infrared spectrometer and imager, to monitor thermal emission from Io's volcanoes. JIRAM near-infrared spectroscopy has so far allowed for the coarse mapping of sulfur dioxide frost across Io's surface as well as mapping minor surface components weakly absorbing sunlight at 2.1 and 2.65 μm.

Future missions
There are two forthcoming missions planned for the Jovian system. The Jupiter Icy Moon Explorer (JUICE) is a planned European Space Agency mission to the Jovian system that is intended to end up in Ganymede orbit. JUICE launched in April 2023, with arrival at Jupiter planned for July 2031. JUICE will not fly by Io, but it will use its instruments, such as a narrow-angle camera, to monitor Io's volcanic activity and measure its surface composition during the two-year Jupiter-tour phase of the mission prior to Ganymede orbit insertion. Europa Clipper is a planned NASA mission to the Jovian system focused on Jupiter's moon Europa. Like JUICE, Europa Clipper will not perform any flybys of Io, but distant volcano monitoring is likely. Europa Clipper has a planned launch in 2024 with an arrival at Jupiter in 2030.

The Io Volcano Observer (IVO) was a proposal to NASA for a low-cost, Discovery-class mission selected for a Phase A study along with three other missions in 2020. IVO would launch in January 2029 and perform ten flybys of Io while in orbit around Jupiter beginning in the early 2030s. However, the Venus missions DAVINCI+ and VERITAS were selected in favor of those.

Orbit and rotation

Io orbits Jupiter at a distance of 421700 km from Jupiter's center and 350000 km from its cloudtops. It is the innermost of the Galilean satellites of Jupiter, its orbit lying between those of Thebe and Europa. Including Jupiter's inner satellites, Io is the fifth moon out from Jupiter. It takes Io about 42.5 hours (1.77 days) to complete one orbit around Jupiter (fast enough for its motion to be observed over a single night of observation). Io is in a 2:1 mean-motion orbital resonance with Europa and a 4:1 mean-motion orbital resonance with Ganymede, completing two orbits of Jupiter for every one orbit completed by Europa, and four orbits for every one completed by Ganymede. This resonance helps maintain Io's orbital eccentricity (0.0041), which in turn provides the primary heating source for its geologic activity. Without this forced eccentricity, Io's orbit would circularize through tidal dissipation, leading to a less geologically active world.

Like the other Galilean satellites and the Moon, Io rotates synchronously with its orbital period, keeping one face nearly pointed toward Jupiter. This synchrony provides the definition for Io's longitude system. Io's prime meridian intersects the equator at the sub-Jovian point. The side of Io that always faces Jupiter is known as the subjovian hemisphere, whereas the side that always faces away is known as the antijovian hemisphere. The side of Io that always faces in the direction that Io travels in its orbit is known as the leading hemisphere, whereas the side that always faces in the opposite direction is known as the trailing hemisphere.

From the surface of Io, Jupiter would subtend an arc of 19.5°, making Jupiter appear 39 times the apparent diameter of Earth's Moon.

Interaction with Jupiter's magnetosphere
Io plays a significant role in shaping Jupiter's magnetic field, acting as an electric generator that can develop 400,000 volts across itself and create an electric current of 3 million amperes, releasing ions that give Jupiter a magnetic field inflated to more than twice the size it would otherwise have. The magnetosphere of Jupiter sweeps up gases and dust from Io's thin atmosphere at a rate of 1 tonne per second. This material is mostly composed of ionized and atomic sulfur, oxygen and chlorine; atomic sodium and potassium; molecular sulfur dioxide and sulfur; and sodium chloride dust. These materials originate from Io's volcanic activity, with the material that escapes to Jupiter's magnetic field and into interplanetary space coming directly from Io's atmosphere. These materials, depending on their ionized state and composition, end up in various neutral (non-ionized) clouds and radiation belts in Jupiter's magnetosphere and, in some cases, are eventually ejected from the Jovian system.

Surrounding Io (at a distance of up to six Io radii from its surface) is a cloud of neutral sulfur, oxygen, sodium, and potassium atoms. These particles originate in Io's upper atmosphere and are excited by collisions with ions in the plasma torus (discussed below) and by other processes into filling Io's Hill sphere, which is the region where Io's gravity is dominant over Jupiter's. Some of this material escapes Io's gravitational pull and goes into orbit around Jupiter. Over a 20-hour period, these particles spread out from Io to form a banana-shaped, neutral cloud that can reach as far as six Jovian radii from Io, either inside Io's orbit and ahead of it or outside Io's orbit and behind it. The collision process that excites these particles also occasionally provides sodium ions in the plasma torus with an electron, removing those new "fast" neutrals from the torus. These particles retain their velocity (70 km/s, compared to the 17 km/s orbital velocity at Io), and are thus ejected in jets leading away from Io.

Io orbits within a belt of intense radiation known as the Io plasma torus. The plasma in this doughnut-shaped ring of ionized sulfur, oxygen, sodium, and chlorine originates when neutral atoms in the "cloud" surrounding Io are ionized and carried along by the Jovian magnetosphere. Unlike the particles in the neutral cloud, these particles co-rotate with Jupiter's magnetosphere, revolving around Jupiter at 74 km/s. Like the rest of Jupiter's magnetic field, the plasma torus is tilted with respect to Jupiter's equator (and Io's orbital plane), so that Io is at times below and at other times above the core of the plasma torus. As noted above, these ions' higher velocity and energy levels are partly responsible for the removal of neutral atoms and molecules from Io's atmosphere and more extended neutral clouds. The torus is composed of three sections: an outer, "warm" torus that resides just outside Io's orbit; a vertically extended region known as the "ribbon", composed of the neutral source region and cooling plasma, located at around Io's distance from Jupiter; and an inner, "cold" torus, composed of particles that are slowly spiraling in toward Jupiter. After residing an average of 40 days in the torus, particles in the "warm" torus escape and are partially responsible for Jupiter's unusually large magnetosphere, their outward pressure inflating it from within. Particles from Io, detected as variations in magnetospheric plasma, have been detected far into the long magnetotail by New Horizons. To study similar variations within the plasma torus, researchers measured the ultraviolet light it emits. Although such variations have not been definitively linked to variations in Io's volcanic activity (the ultimate source for material in the plasma torus), this link has been established in the neutral sodium cloud.

During an encounter with Jupiter in 1992, the Ulysses spacecraft detected a stream of dust-sized particles being ejected from the Jovian system. The dust in these discrete streams travels away from Jupiter at speeds upwards of several hundred kilometers per second, has an average particle size of 10 μm, and consists primarily of sodium chloride. Dust measurements by Galileo showed that these dust streams originated on Io, but exactly how these form, whether from Io's volcanic activity or material removed from the surface, is unknown.

Jupiter's magnetic field, which Io crosses, couples Io's atmosphere and neutral cloud to Jupiter's polar upper atmosphere by generating an electric current known as the Io flux tube. This current produces an auroral glow in Jupiter's polar regions known as the Io footprint, as well as aurorae in Io's atmosphere. Particles from this auroral interaction darken the Jovian polar regions at visible wavelengths. The location of Io and its auroral footprint with respect to Earth and Jupiter has a strong influence on Jovian radio emissions from our vantage point: when Io is visible, radio signals from Jupiter increase considerably. The Juno mission, currently in orbit around Jupiter, should help shed light on these processes. The Jovian magnetic field lines that do get past Io's ionosphere also induce an electric current, which in turn creates an induced magnetic field within Io's interior. Io's induced magnetic field is thought to be generated within a partially molten, silicate magma ocean 50 kilometers beneath Io's surface. Similar induced fields were found at the other Galilean satellites by Galileo, possibly generated within liquid water oceans in the interiors of those moons.

Geology
Io is slightly larger than Earth's Moon. It has a mean radius of 1821.3 km (about 5% greater than the Moon's) and a mass of 8.9319 kg (about 21% greater than the Moon's). It is a slight ellipsoid in shape, with its longest axis directed toward Jupiter. Among the Galilean satellites, in both mass and volume, Io ranks behind Ganymede and Callisto but ahead of Europa.

Interior
Composed primarily of silicate rock and iron, Io and Europa are closer in bulk composition to terrestrial planets than to other satellites in the outer Solar System, which are mostly composed of a mix of water ice and silicates. Io has a density of $421,700 km$, the highest of any regular moon in the Solar System; significantly higher than the other Galilean satellites (Ganymede and Callisto in particular, whose densities are around $0.003 AU$) and slightly higher (~5.5%) than the Moon's $0.004$ and Europa's $420,000 km$. Models based on the Voyager and Galileo measurements of Io's mass, radius, and quadrupole gravitational coefficients (numerical values related to how mass is distributed within an object) suggest that its interior is differentiated between a silicate-rich crust and mantle and an iron- or iron-sulfide-rich core. Io's metallic core makes up approximately 20% of its mass. Depending on the amount of sulfur in the core, the core has a radius between 350 and(-) if it is composed almost entirely of iron, or between 550 and(-) for a core consisting of a mix of iron and sulfur. Galileo magnetometer failed to detect an internal, intrinsic magnetic field at Io, suggesting that the core is not convecting.

Modeling of Io's interior composition suggests that the mantle is composed of at least 75% of the magnesium-rich mineral forsterite, and has a bulk composition similar to that of L-chondrite and LL-chondrite meteorites, with higher iron content (compared to silicon) than the Moon or Earth, but lower than Mars. To support the heat flow observed on Io, 10–20% of Io's mantle may be molten, though regions where high-temperature volcanism has been observed may have higher melt fractions. However, re-analysis of Galileo magnetometer data in 2009 revealed the presence of an induced magnetic field at Io, requiring a magma ocean 50 km below the surface. Further analysis published in 2011 provided direct evidence of such an ocean. This layer is estimated to be 50 km thick and to make up about 10% of Io's mantle. It is estimated that the temperature in the magma ocean reaches 1,200 °C. It is not known if the 10–20% partial melting percentage for Io's mantle is consistent with the requirement for a significant amount of molten silicates in this possible magma ocean. The lithosphere of Io, composed of basalt and sulfur deposited by Io's extensive volcanism, is at least 12 km thick, and likely less than 40 km thick.

Tidal heating
Unlike Earth and the Moon, Io's main source of internal heat comes from tidal dissipation rather than radioactive isotope decay, the result of Io's orbital resonance with Europa and Ganymede. Such heating is dependent on Io's distance from Jupiter, its orbital eccentricity, the composition of its interior, and its physical state. Its Laplace resonance with Europa and Ganymede maintains Io's eccentricity and prevents tidal dissipation within Io from circularizing its orbit. The resonant orbit also helps to maintain Io's distance from Jupiter; otherwise tides raised on Jupiter would cause Io to slowly spiral outward from its parent planet. The tidal forces experienced by Io are about 20,000 times stronger than the tidal forces Earth experiences due to the Moon, and the vertical differences in its tidal bulge, between the times Io is at periapsis and apoapsis in its orbit, could be as much as 100 m. The friction or tidal dissipation produced in Io's interior due to this varying tidal pull, which, without the resonant orbit, would have gone into circularizing Io's orbit instead, creates significant tidal heating within Io's interior, melting a significant amount of Io's mantle and core. The amount of energy produced is up to 200 times greater than that produced solely from radioactive decay. This heat is released in the form of volcanic activity, generating its observed high heat flow (global total: 0.6 to 1.6×1014 W). Models of its orbit suggest that the amount of tidal heating within Io changes with time; however, the current amount of tidal dissipation is consistent with the observed heat flow. Models of tidal heating and convection have not found consistent planetary viscosity profiles that simultaneously match tidal energy dissipation and mantle convection of heat to the surface.

Although there is general agreement that the origin of the heat as manifested in Io's many volcanoes is tidal heating from the pull of gravity from Jupiter and its moon Europa, the volcanoes are not in the positions predicted with tidal heating. They are shifted 30 to 60 degrees to the east. A study published by Tyler et al. (2015) suggests that this eastern shift may be caused by an ocean of molten rock under the surface. The movement of this magma would generate extra heat through friction due to its viscosity. The study's authors believe that this subsurface ocean is a mixture of molten and solid rock.

Other moons in the Solar System are also tidally heated, and they too may generate additional heat through the friction of subsurface magma or water oceans. This ability to generate heat in a subsurface ocean increases the chance of life on bodies like Europa and Enceladus.

Surface

Based on their experience with the ancient surfaces of the Moon, Mars, and Mercury, scientists expected to see numerous impact craters in Voyager 1 first images of Io. The density of impact craters across Io's surface would have given clues to Io's age. However, they were surprised to discover that the surface was almost completely lacking in impact craters, but was instead covered in smooth plains dotted with tall mountains, pits of various shapes and sizes, and volcanic lava flows. Compared to most worlds observed to that point, Io's surface was covered in a variety of colorful materials (leading Io to be compared to a rotten orange or to pizza) from various sulfurous compounds. The lack of impact craters indicated that Io's surface is geologically young, like the terrestrial surface; volcanic materials continuously bury craters as they are produced. This result was spectacularly confirmed as at least nine active volcanoes were observed by Voyager 1.

Surface composition
Io's colorful appearance is the result of materials deposited by its extensive volcanism, including silicates (such as orthopyroxene), sulfur, and sulfur dioxide. Sulfur dioxide frost is ubiquitous across the surface of Io, forming large regions covered in white or grey materials. Sulfur is also seen in many places across Io, forming yellow to yellow-green regions. Sulfur deposited in the mid-latitude and polar regions is often damaged by radiation, breaking up the normally stable cyclic 8-chain sulfur. This radiation damage produces Io's red-brown polar regions.

Explosive volcanism, often taking the form of umbrella-shaped plumes, paints the surface with sulfurous and silicate materials. Plume deposits on Io are often colored red or white depending on the amount of sulfur and sulfur dioxide in the plume. Generally, plumes formed at volcanic vents from degassing lava contain a greater amount of S2, producing a red "fan" deposit, or in extreme cases, large (often reaching beyond 450 km from the central vent) red rings. A prominent example of a red-ring plume deposit is located at Pele. These red deposits consist primarily of sulfur (generally 3- and 4-chain molecular sulfur), sulfur dioxide, and perhaps sulfuryl chloride. Plumes formed at the margins of silicate lava flows (through the interaction of lava and pre-existing deposits of sulfur and sulfur dioxide) produce white or gray deposits.

Compositional mapping and Io's high density suggest that Io contains little to no water, though small pockets of water ice or hydrated minerals have been tentatively identified, most notably on the northwest flank of the mountain Gish Bar Mons. Io has the least amount of water of any known body in the Solar System. This lack of water is likely due to Jupiter being hot enough early in the evolution of the Solar System to drive off volatile materials like water in the vicinity of Io, but not hot enough to do so farther out.

Volcanism
The tidal heating produced by Io's forced orbital eccentricity has made it the most volcanically active world in the Solar System, with hundreds of volcanic centers and extensive lava flows. During a major eruption, lava flows tens or even hundreds of kilometers long can be produced, consisting mostly of basalt silicate lavas with either mafic or ultramafic (magnesium-rich) compositions. As a by-product of this activity, sulfur, sulfur dioxide gas and silicate pyroclastic material (like ash) are blown up to 200 km into space, producing large, umbrella-shaped plumes, painting the surrounding terrain in red, black, and white, and providing material for Io's patchy atmosphere and Jupiter's extensive magnetosphere. Io's surface is dotted with volcanic depressions known as paterae which generally have flat floors bounded by steep walls. These features resemble terrestrial calderas, but it is unknown if they are produced through collapse over an emptied lava chamber like their terrestrial cousins. One hypothesis suggests that these features are produced through the exhumation of volcanic sills, and the overlying material is either blasted out or integrated into the sill. Examples of paterae in various stages of exhumation have been mapped using Galileo images of the Chaac-Camaxtli region. Unlike similar features on Earth and Mars, these depressions generally do not lie at the peak of shield volcanoes and are normally larger, with an average diameter of 41 km, the largest being Loki Patera at 202 km. Loki is also consistently the strongest volcano on Io, contributing on average 25% of Io's global heat output. Whatever the formation mechanism, the morphology and distribution of many paterae suggest that these features are structurally controlled, with at least half bounded by faults or mountains. These features are often the site of volcanic eruptions, either from lava flows spreading across the floors of the paterae, as at an eruption at Gish Bar Patera in 2001, or in the form of a lava lake. Lava lakes on Io either have a continuously overturning lava crust, such as at Pele, or an episodically overturning crust, such as at Loki.

Lava flows represent another major volcanic terrain on Io. Magma erupts onto the surface from vents on the floor of paterae or on the plains from fissures, producing inflated, compound lava flows similar to those seen at Kilauea in Hawaii. Images from the Galileo spacecraft revealed that many of Io's major lava flows, like those at Prometheus and Amirani, are produced by the build-up of small breakouts of lava flows on top of older flows. Larger outbreaks of lava have also been observed on Io. For example, the leading edge of the Prometheus flow moved 75 to 95 km between Voyager in 1979 and the first Galileo observations in 1996. A major eruption in 1997 produced more than 3500 km2 of fresh lava and flooded the floor of the adjacent Pillan Patera.

Analysis of the Voyager images led scientists to believe that these flows were composed mostly of various compounds of molten sulfur. However, subsequent Earth-based infrared studies and measurements from the Galileo spacecraft indicate that these flows are composed of basaltic lava with mafic to ultramafic compositions. This hypothesis is based on temperature measurements of Io's "hotspots", or thermal-emission locations, which suggest temperatures of at least 1,300 K and some as high as 1,600 K. Initial estimates suggesting eruption temperatures approaching 2,000 K have since proven to be overestimates because the wrong thermal models were used to model the temperatures.

The discovery of plumes at the volcanoes Pele and Loki were the first sign that Io is geologically active. Generally, these plumes are formed when volatiles like sulfur and sulfur dioxide are ejected skyward from Io's volcanoes at speeds reaching 1 km/s, creating umbrella-shaped clouds of gas and dust. Additional material that might be found in these volcanic plumes include sodium, potassium, and chlorine. These plumes appear to be formed in one of two ways. Io's largest plumes, such as those emitted by Pele, are created when dissolved sulfur and sulfur dioxide gas are released from erupting magma at volcanic vents or lava lakes, often dragging silicate pyroclastic material with them. These plumes form red (from the short-chain sulfur) and black (from the silicate pyroclastics) deposits on the surface. Plumes formed in this manner are among the largest observed at Io, forming red rings more than 1000 km in diameter. Examples of this plume type include Pele, Tvashtar, and Dazhbog. Another type of plume is produced when encroaching lava flows vaporize underlying sulfur dioxide frost, sending the sulfur skyward. This type of plume often forms bright circular deposits consisting of sulfur dioxide. These plumes are often less than 100 km tall, and are among the most long-lived plumes on Io. Examples include Prometheus, Amirani, and Masubi. The erupted sulfurous compounds are concentrated in the upper crust from a decrease in sulfur solubility at greater depths in Io's lithosphere and can be a determinant for the eruption style of a hot spot.

Mountains
Io has 100 to 150 mountains. These structures average 6 km in height and reach a maximum of 17.5 ± at South Boösaule Montes. Mountains often appear as large (the average mountain is 157 km long), isolated structures with no apparent global tectonic patterns outlined, in contrast to the case on Earth. To support the tremendous topography observed at these mountains requires compositions consisting mostly of silicate rock, as opposed to sulfur.

Despite the extensive volcanism that gives Io its distinctive appearance, nearly all of its mountains are tectonic structures, and are not produced by volcanoes. Instead, most Ionian mountains form as the result of compressive stresses on the base of the lithosphere, which uplift and often tilt chunks of Io's crust through thrust faulting. The compressive stresses leading to mountain formation are the result of subsidence from the continuous burial of volcanic materials. The global distribution of mountains appears to be opposite that of volcanic structures; mountains dominate areas with fewer volcanoes and vice versa. This suggests large-scale regions in Io's lithosphere where compression (supportive of mountain formation) and extension (supportive of patera formation) dominate. Locally, however, mountains and paterae often abut one another, suggesting that magma often exploits faults formed during mountain formation to reach the surface.

Mountains on Io (generally, structures rising above the surrounding plains) have a variety of morphologies. Plateaus are most common. These structures resemble large, flat-topped mesas with rugged surfaces. Other mountains appear to be tilted crustal blocks, with a shallow slope from the formerly flat surface and a steep slope consisting of formerly sub-surface materials uplifted by compressive stresses. Both types of mountains often have steep scarps along one or more margins. Only a handful of mountains on Io appear to have a volcanic origin. These mountains resemble small shield volcanoes, with steep slopes (6–7°) near a small, central caldera and shallow slopes along their margins. These volcanic mountains are often smaller than the average mountain on Io, averaging only 1 to 2 km in height and 40 to 60 km wide. Other shield volcanoes with much shallower slopes are inferred from the morphology of several of Io's volcanoes, where thin flows radiate out from a central patera, such as at Ra Patera.

Nearly all mountains appear to be in some stage of degradation. Large landslide deposits are common at the base of Ionian mountains, suggesting that mass wasting is the primary form of degradation. Scalloped margins are common among Io's mesas and plateaus, the result of sulfur dioxide sapping from Io's crust, producing zones of weakness along mountain margins.

Atmosphere

Io has an extremely thin atmosphere consisting mainly of sulfur dioxide, with minor constituents including sulfur monoxide , sodium chloride , and atomic sulfur and oxygen. The atmosphere has significant variations in density and temperature with time of day, latitude, volcanic activity, and surface frost abundance. The maximum atmospheric pressure on Io ranges from 3.3$0.003 AU$ to 3$423,400 km$ pascals (Pa) or 0.3 to 3 nbar, spatially seen on Io's anti-Jupiter hemisphere and along the equator, and temporally in the early afternoon when the temperature of surface frost peaks. Localized peaks at volcanic plumes have also been seen, with pressures of 5$0.003 AU$ to 40 $1.769 d$ Pa (5 to 40 nbar). Io's atmospheric pressure is lowest on Io's night side, where the pressure dips to 0.1$152,853.505 s$ to 1$42.459 h$ Pa (0.0001 to 0.001 nbar). Io's atmospheric temperature ranges from the temperature of the surface at low altitudes, where sulfur dioxide is in vapor pressure equilibrium with frost on the surface, to 1,800 K at higher altitudes where the lower atmospheric density permits heating from plasma in the Io plasma torus and from Joule heating from the Io flux tube. The low pressure limits the atmosphere's effect on the surface, except for temporarily redistributing sulfur dioxide from frost-rich to frost-poor areas, and to expand the size of plume deposit rings when plume material re-enters the thicker dayside atmosphere.

Gas in Io's atmosphere is stripped by Jupiter's magnetosphere, escaping to either the neutral cloud that surrounds Io, or the Io plasma torus, a ring of ionized particles that shares Io's orbit but co-rotates with the magnetosphere of Jupiter. Approximately one ton of material is removed from the atmosphere every second through this process so that it must be constantly replenished. The most dramatic source of are volcanic plumes, which pump  kg of sulfur dioxide per second into Io's atmosphere on average, though most of this condenses back onto the surface. Much of the sulfur dioxide in Io's atmosphere is sustained by sunlight-driven sublimation of frozen on the surface. The day-side atmosphere is largely confined to within 40° of the equator, where the surface is warmest and most active volcanic plumes reside. A sublimation-driven atmosphere is also consistent with observations that Io's atmosphere is densest over the anti-Jupiter hemisphere, where frost is most abundant, and is densest when Io is closer to the Sun. However, some contributions from volcanic plumes are required as the highest observed densities have been seen near volcanic vents. Because the density of sulfur dioxide in the atmosphere is tied directly to surface temperature, Io's atmosphere partially collapses at night, or when Io is in the shadow of Jupiter (with an ~80% drop in column density ). The collapse during eclipse is limited somewhat by the formation of a diffusion layer of sulfur monoxide in the lowest portion of the atmosphere, but the atmosphere pressure of Io's nightside atmosphere is two to four orders of magnitude less than at its peak just past noon. The minor constituents of Io's atmosphere, such as, , , and derive either from: direct volcanic outgassing; photodissociation, or chemical breakdown caused by solar ultraviolet radiation, from ; or the sputtering of surface deposits by charged particles from Jupiter's magnetosphere.

Various researchers have proposed that the atmosphere of Io freezes onto the surface when it passes into the shadow of Jupiter. Evidence for this is a "post-eclipse brightening", where the moon sometimes appears a bit brighter as if covered with frost immediately after eclipse. After about 15 minutes the brightness returns to normal, presumably because the frost has disappeared through sublimation. Besides being seen through ground-based telescopes, post-eclipse brightening was found in near-infrared wavelengths using an instrument aboard the Cassini spacecraft. Further support for this idea came in 2013 when the Gemini Observatory was used to directly measure the collapse of Io's SO2 atmosphere during, and its reformation after, eclipse with Jupiter.

High-resolution images of Io acquired when Io is experiencing an eclipse reveal an aurora-like glow. As on Earth, this is due to particle radiation hitting the atmosphere, though in this case the charged particles come from Jupiter's magnetic field rather than the solar wind. Aurorae usually occur near the magnetic poles of planets, but Io's are brightest near its equator. Io lacks an intrinsic magnetic field of its own; therefore, electrons traveling along Jupiter's magnetic field near Io directly impact Io's atmosphere. More electrons collide with its atmosphere, producing the brightest aurora, where the field lines are tangent to Io (i.e. near the equator), because the column of gas they pass through is the longest there. Aurorae associated with these tangent points on Io are observed to rock with the changing orientation of Jupiter's tilted magnetic dipole. Fainter aurora from oxygen atoms along the limb of Io (the red glows in the image at right), and sodium atoms on Io's night-side (the green glows in the same image) have also been observed.

General information

 * Io profile at NASA's Solar System Exploration site
 * Bill Arnett's Io webpage from The Nine Planets website
 * Io overview from the University of Michigan's Windows to the Universe
 * Calvin Hamilton's Io page from the Views of the Solar System website

Movies

 * Paul Schenk's 3D images and flyover videos of Io and other outer solar system satellites
 * High resolution video simulation of rotating Io by Seán Doran

Images

 * Catalog of NASA images of Io
 * Galileo images of Io
 * New Horizons images of Io
 * New Horizons LORRI Raw Images, includes numerous Io images
 * Io through Different New Horizons Imagers

Maps

 * Io global basemaps at the USGS Astrogeology Science Center based on Galileo and Voyager images
 * Io nomenclature and map with feature names from the USGS planetary nomenclature page
 * Interactive map of Io by Google Maps

Additional references

 * Io dynamo from educational website The Exploration of the Earth's Magnetosphere

 * NASA's Stunning Discoveries on Jupiter's Largest Moons | Our Solar System's Moons

 * The Conundrum Posed by Io's Minimum Surface Temperatures
 * Io Mountain Database
 * Cassini Observations of Io's Visible Aurorae at the USGS Astrogeology Science Center
 * The Gish Bar Times, Jason Perry's Io-related blog

title: Io (moon)


text:
Talk:Io (moon)

Note
Galileo himself noted that Marius used the Julian calendar while Galileo used the Gregorian one. This is not made clear as it is. Of course, the two calendars and the different parties using them are well known. — Preceding unsigned comment added by 92.26.0.234 (talk) 14:26, 22 September 2014 (UTC)
 * The date of Galileo's publication, 1610, is not logical proof that he made any observations before Marius. Galileo's direct argumentation should be used. I think his argumentation is indeed proof that he did have priority, not that it is very important. — Preceding unsigned comment added by 92.26.0.234 (talk) 14:34, 22 September 2014 (UTC)
 * Logical or not, publication was traditionally used to determine priority as it was the first evidence that was available to people in general (and possibly because it encouraged people to publish?)

IceDragon64 (talk) 23:06, 20 January 2019 (UTC)

Water on Io
The introduction states that Io has the least amount of water of any celestial body; that would include the Sun, planet Venus and the tiniest asteroids. A user held a hot debate about that topic on Tbayboy's talk page and this link provided by the user states there might a sub-surface ocean on Io just like on the other Galilean moons. Maybe the introduction should better say Io has the least water out of all moons, that would certainly be true (if the assumption of a sub-surface ocean is wrong), but not every celestial body. Come on! Io can't have less water than the Sun or tiny asteroids, can it? -- 12:34, 6 May 2019 (UTC)
 * Some more context: There's a statement in Surface Composition saying "Io has the least amount of water of any known body in the Solar System", with a reference to a published textbook. It's also repeated in the lead.
 * My own comments:
 * The German page above doesn't seem reliable: Given Io's constant volcanism, any sub-surface ocean would be coming out with the eruptions and would be spewed across the surface or in the plumes. It would be easily seen. I think the author got confused reading about Io's possible sub-surface magma ocean and its comparison with the water oceans of the other moons.
 * Does the source say Io has the least total mass of water, or the least fraction? It's hard to believe that Io, dry as it is, has less water than some little asteroid.
 * If it's water fraction, wouldn't the Sun have less? Or was it implicit in the source that the Sun was excluded?
 * Most importantly, is there any data on the quantity/fraction of water in all known bodies for this statement to have any meaning? I find it hard to believe they even know how much water Io has at all, if you include possible internal supplies.
 * It's certainly worth noting how dry Io is, but saying it has the least water seems a stretch. Could somebody with access to the source (Seeds, Michael A.; Backman, Dana E. (2012). The Solar System (8th ed.). Cengage Learning. p. 514. ISBN 9781133713685) please check it? Tbayboy (talk) 15:36, 6 May 2019 (UTC)
 * Sub-surface MAGMA ocean, not water. Based on spectroscopic measurements going back to the 1970s all the way through Galileo NIMS have found no evidence for water ice on Io beyond some evidence for hydrated minerals north of Gish Bar Mons, though other molecules are possible candidates including SO3 and S2O (or other polysulfoxydes) (Doute et al. 2004). Is it possible there is water locked in Io's interior?  Sure, I guess anything is possible, but this is a world that literally spits its interior out into space and back onto its surface.  If there was water in its interior, it should have been observed either through spectroscopy of surface frosts and volcanic plume deposits or by observing Io's plumes as they transit a star.  At least water vapor has been found at the Sun... Volcanopele (talk) 20:20, 6 May 2019 (UTC)
 * The source claims there might be a water ocean beneath Io. On the Sun, where does the water vapor come from? -- 06:41, 7 May 2019 (UTC)
 * I think that source is wrong: they confused magma ocean with water ocean. It's just a pop-sci website, and I couldn't find anybody else making that claim with a quick google. On the Sun, there's lots of hydrogen and a bit of oxygen, and they cool enough to combine for a while in sunspots. Tbayboy (talk) 11:53, 7 May 2019 (UTC)
 * The source might err, but I still don't believe that Io has less water than 10-feet-long meteoroids. 212.186.0.174 (talk) 13:52, 7 May 2019 (UTC)
 * 10-feet long meteoroids can have a lot of water. Ruslik_ Zero 06:20, 8 May 2019 (UTC)
 * More than Io has? 212.186.0.174 (talk) 08:28, 8 May 2019 (UTC)
 * If you see my question why don't you respond? If you don't know, say that you aren't sure. 212.186.0.174 (talk) 11:04, 10 May 2019 (UTC)
 * We (obviously) don't know the hard numbers. There may not even be any numbers. But Wikipedia goes by sources, not what we surmise, and all the reliable sources say Io is about as dry as it gets. Asteroids, generally, aren't that dry (water is bound up in the rock). Without any reliable sources to the contrary, we go with what the one referenced in the article says. I would like to check that the statement here matches the source, but don't have access to the source. Tbayboy (talk) 12:06, 10 May 2019 (UTC)
 * I think it's anyway unwise to mention the absolute amount of water rather than the amount relative to the size of the body. If one mentioned the latter one I think Io has a higher percentage of water than the Sun or Venus. 212.186.0.174 (talk) 17:07, 10 May 2019 (UTC)
 * If you can find a reliable source stating the moon Io has water, or any facts about the amount of water on IO, then link it and edit the article, but if we can't find a reliable source, we can't add it. MaximusEditor (talk) 09:25, 24 September 2020 (UTC)

FA sweeps
There are some issues with the article including over a dozen cn tags, some issues (the ones that I found are marked in the article), and some verifiability issues with page ranges of 20 pages or more. (t · c)  buidhe  08:31, 13 February 2022 (UTC)

Requested move 17 September 2023

 * The following is a closed discussion of a requested move. Please do not modify it. Subsequent comments should be made in a new section on the talk page. Editors desiring to contest the closing decision should consider a move review after discussing it on the closer's talk page. No further edits should be made to this discussion.

The result of the move request was: Not moved – consensus here seems skeptical of the idea that the moon is the primary topic. ErikHaugen (talk | contribs) 20:43, 26 September 2023 (UTC)

– The moon, which played a pivotal role in our early understanding of the solar system, is clearly the primary topic by long term significance. It also appears to be primary by page views; it received around two thirds of the views of all topics with the name Io in the past year, and around three times as many as the next most common, Io (mythology). Even when we include .io, which is differentiated by the lowercase and by the dot per WP:SMALLDIFFS and thus isn't directly relevant to what the primary topic for Io is, it receives approximately half of the total views for all topics, and about twice as many as .io itself. BilledMammal (talk) 07:09, 17 September 2023 (UTC) The discussion above is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.
 * Io (moon) → Io
 * Io → Io (disambiguation)
 * Oppose per consistency. Except for the planets (and Pluto) that are named after mythological figures, the base name tends to be a disambiguation page: Europa, Callisto, Ganymede, Ceres, Vesta, Pallas, Eris, Sedna, Titan, Rhea, Tethys, Triton... Egsan Bacon (talk) 15:59, 17 September 2023 (UTC)
 * WP:CONSISTENT says explicitly that we do not strive for consistency when it comes to requiring disambiguation. Orange (color) doesn't necessitate Red (color). This is literally policy. Red   Slash  18:57, 17 September 2023 (UTC)
 * Support as proposed. Well said, both criteria of PRIMARYTOPIC lean this way. Red   Slash  18:55, 17 September 2023 (UTC)
 * Weak support. The film looks like it is really IO (film) (I'll follow up with another RM once this is one is decided), so it's really between the moon and its namesake. Even discounting the film, the page view advantage isn't huge, especially given the number of other topics with this basename, and WikiNav shows the two are nearly equally sought by users reaching the dab page, which is a non-trivial number, ~5k. I think there are long-term signicance arguments on both sides. All in all I think this could go either way, but the page views do weigh slightly in favor of making the moon the primary topic. Probably the disambiguation regarding all major moon articles should be revisited with this sort of analysis. It shouldn't necessarily be that planets win out over deities but moons generally do not as it currently seems; every title should be examined by primary topic criteria individually. Of course the problem is that some titles like Europa have a lot of other uses to consider. Mdewman6 (talk) 23:15, 17 September 2023 (UTC)
 * Oppose per Egsan Bacon. Also, there are 62 entries listed upon the Io / IO / iO / I/O / i/o / i.o. disambiguation page — too many for one topic to be presented as primary over the combined notability of the remaining 61 entries. —Roman Spinner (talk • contribs) 00:34, 18 September 2023 (UTC)
 * We already place it among the two entries at the top, and https://wikinav.toolforge.org/?language=en&title=Io indicates that these two meanings take the lion's share of outgoing clickstreams, each the same ratio, which certainly doesn't indicate that the moon is primary over the other meanings. The computing concept of IO has at least a comparable amount of long-term significance in its field. This actually indicates that other meanings with significance are effectively being hidden from view by being part of the huge list below. In any case, I think we need a better rationale than this to make a change. (Oppose) --Joy (talk) 08:35, 18 September 2023 (UTC)
 * IO is differentiated by WP:SMALLDIFFS; it will, of course, still redirect to Io (disambiguation). BilledMammal (talk) 08:42, 18 September 2023 (UTC)
 * But that doesn't matter for the purposes of this discussion - IO redirects to Io already, presumably because we expect the average user to type "io" when they might mean "IO" often enough, which in turn does not seem like an unreasonable expectation. --Joy (talk) 11:27, 18 September 2023 (UTC)
 * I assume it's because there is no primary topic for IO; for example, the movie using that stylization. BilledMammal (talk) 11:32, 18 September 2023 (UTC)
 * Since there doesn't seem to be primary topic for Io by usage, either, this is moot. --Joy (talk) Joy (talk) 18:22, 19 September 2023 (UTC)
 * Support per WP:PRIMARYTOPIC. Rreagan007 (talk) 21:32, 18 September 2023 (UTC)
 * Oppose per consistency and views arguments above. There is no primary topic. -- Netoholic @ 01:24, 19 September 2023 (UTC)
 * Weak oppose .io isn't really covered by WP:SMALLDETAILS as ".io" is a variant of "Io" not the other way round. Yes the moon comes to mind first but given all the other uses of the 2 letter term I don't see a clear primary topic.  Crouch, Swale  ( talk ) 18:32, 19 September 2023 (UTC)
 * Oppose this primarytopic takeover. The disambiguation serves well, with two main uses acknowledged.  Dicklyon (talk) 20:16, 22 September 2023 (UTC)
 * Oppose no primary topic. 217.180.228.138 (talk) 03:31, 24 September 2023 (UTC)
 * Oppose per Egsan Bacon where many moon names listed as well as Mercury and Ariel where they each list a lot of entries covered. Mythology and the moon are the most well known for Io.
 * Support per nomination. Clearly the WP:PTOPIC long-term significance, much more than any obscure character in Greek mythology. Edward-Woodrow  •  talk  14:24, 24 September 2023 (UTC)

Infobox image: true color or full disk?
Pinging

I noticed that you two have different agendas when it comes to choosing which image is appropriate for the infoboxes of Solar System objects. CactiStaccingCrane prefers having true-color images, even when they may not show the whole view like in the case for Venus, whereas Nosferattus prefers having whole-disk images that represent the body as much as possible, with the expense of sacrificing color and data accuracy as in the case of Triton, whose colors are enhanced to appear iridescent and images are projected onto a 3D sphere that is being viewed from an angle that was not achievable by Voyager 2.

I need you two to agree on which Io image to use since this article had a minor conflict regarding that: changed the infobox image to the true-color Juno photo but Norsferattus reverted the image change, citing that full-disk and featured images are preferred. However, I am not aware of any official guideline that explicitly says that, let alone anybody else who vocally supports this set of criteria.

Personally, I prefer using true-color images since these portray the objects the most realistically (duh). I believe using true-color images as the lead image (and explicitly stating which images are true or enhanced color throughout the article) is necessary to avoid misleading the reader--recall the news about Neptune's true color, which led to CactiStaccingCrane and I replacing the deep blue Neptune image everywhere on Wikipedia. As I mentioned earlier, true color images may come with the downside of partial views (crescent or out of frame) since there aren't many of them out there (either due to limited spacecraft imaging, filters, or people who focus on processing true-color). However, if having full-frame and full-disk images is what Nosferattus insists for, then Venus's image would need discussion.

As a proponent for true-color, I suggest that we replace the enhanced-color image of Io with this true-color Juno image. This is true color according to this Planetary Society article by expert image processor Jason Perry. Yes, the previous saturated yellow image of Io by NASA also claims true color, but I assure you this is incorrect considering that: 1) NASA's public communication doesn't have a great track record with being clear about colors. Their deep blue Neptune image that has long misled the public is an example. and 2) The saturated yellow Io image uses near-infrared and violet filters that extends beyond the human visible range. Juno uses red, green, and blue filters that fit more within the human visible range. If that doesn't satisfy you all, then we should try looking for a better true color image that is high resolution and free to use (from Flickr).

Nrco0e (talk) 22:09, 23 January 2024 (UTC)

 * Hmm I'm fine with either since I am new here so I don't consider myself as a skilled editor. And I am not very interactive because I am busy always and I edit on my free time
 * But.. but. Remember that Juno will approach Perijove 58 this Feb 3 and will make another pass of Io at the same distance at Perijove 57. Maybe we can get better illuminated photos later.
 * And Juno will continue passing by Io several times starting at Perijove 59, but more and more distant ones as time progress? Long story short my opinion: let us wait for Juno IapetusCallistus (talk) 22:24, 23 January 2024 (UTC)
 * I would note that Juno's cameras are already quite degraded due to Jupiter's radiation belts, and are only going to get worse from here; I wouldn't count on future passes to be any better than what we already have, unfortunately. We also do have better-processed images from older missions such as Galileo which are much more accurate in terms of color and appearance. ArkHyena (talk) 22:45, 23 January 2024 (UTC)
 * In my opinion both of these factors need to be balanced. We should keep the current image since Io's Juno pic seems to not actually be in true color. CactiStaccingCrane (talk) 01:00, 24 January 2024 (UTC)
 * So far as I can tell, Juno's images of Io -- or at the very least, the one which was processed and shown above -- are decently close to Io's true color, especially when compared to the article which attempts to reprocess Galileo images of Io to be closer to true color. ArkHyena (talk) 01:27, 24 January 2024 (UTC)
 * @ArkHyena hmm.. yeah Juno's camera is significantly damaged already. However, I would like to assume that the citizen scientists who are processing these images like Gill, Perry, Jónsson et. at. are all proactively taking the damages into consideration. By the way, off topic - your username Ark Hyena reminds me of a hyena character from Arknights IapetusCallistus (talk) 09:43, 24 January 2024 (UTC)
 * @CactiStaccingCrane@Nrco0e
 * Look at this nice reprocessing. Can anyone find the full picture of this? [[File:Io_Enhanced_%2B_True_Color.webp]]
 * It's a reprocess attempt by the Planetary Society. It's a mostly fully-illuminated true color image of Io. IapetusCallistus (talk) 13:56, 24 January 2024 (UTC)
 * @CactiStaccingCrane@Nrco0e
 * Sorry, ignore my message. I didn't see the fact that you already shared the link to the Planetary Society image. I want to delete the message, but it doesn't look like I can delete it here in Wiki. IapetusCallistus (talk) 14:04, 24 January 2024 (UTC)
 * It may be possible to recruit the help of some people who know much more about image processing to process existing full-disc images from Galileo; if I am not mistaken, Neptune's infobox image was produced that way. However, I personally do not know of anyone who actively contributes to Wikipedia who is also experienced with processing Galileo imagery. ArkHyena (talk) 19:22, 24 January 2024 (UTC)
 * @Ardenau4 Hello again Ardenau. Can you help us again by processing these [|raw pictures of Io] into true color? IapetusCallistus (talk) 22:39, 24 January 2024 (UTC)
 * It appears the link you posted isn't working.
 * Unfortunately, I'm not that experienced with Galileo imagery. Most Galileo images are in IR-G-UV format, and I'm not that experienced with being able to process Galileo imagery in true color from filters that are far removed from the visual spectrum. Voyager imagery might be better, but I'm not super familiar with the Io imaging sequence for either of the Voyager probes. I've actually never processed Io from any spacecraft before so I'm really not sure how to death with such an object.
 * Io is also just a difficult object to deal with in general Io's color is dissimilar to other sola system objects and also that it's hard to calibrate the color contrast on the surface of an object which has a lot of varying colors. I'm not sure I would be able to process any images better than the ones that are posted online already. Ardenau4 (talk) 15:16, 25 January 2024 (UTC)
 * I'm sorry @Ardenau4
 * I don't know why the link is not working when I used "|". Here is the link if you want to check it out properly:
 * https://www.planetary.org/articles/2629
 * Also, it's okay if you can't. Thank you for responding. IapetusCallistus (talk) 16:13, 25 January 2024 (UTC)
 * So I guess... "expert image processor" Jason Perry here.... okay. So let's define the issue here. What is true color? Like your digital camera, it comes down to filter choice. Your digital camera makes the choice with the individual pixels being sensitive to RGB in a Bayer pattern. For spacecraft missions, filters come down to several factors including scientific usage and cost. Before we even get to filters, I should briefly mention why it is relevant for Io. Does this discussion happen over on the Europa page? Ganymede? No, because for Io, differences in the wavelengths your red and blue filters are sensitive to can dramatically change the resulting image. There is a deep absorption band caused by sulfurous materials on Io's surface in the ultraviolet and the wing of that band occurs between 400 and 500 nanometers, in the violet to blue range of the visible spectrum. So if you have a filter closer to 400 nm, then that sulfurous material appears very dark, and if it is closer to 500, then that material has a moderate brightness, and albedo is affected by the presence of certain sulfur allotropes like S4 or by SO2. there is a similar absorption and between 500 and 600 nanometers caused by S4. So areas rich in S4, like some plume deposits or the polar regions can appear reddish in color images and how bright red they are depends on where a red filter is WRT to that absorption band.
 * So how is this relevant here? Galileo didn't have a blue filter but a violet filter. So to generate color images of Io, that violet filter was used in place of blue. The deep absorption band for S meant that areas rich in S8 appear as a deep yellow. Galileo's red filter largely matched that of RGB. JunoCam has some factors that make it more true color, but there are somethings to watch out for and you should all be wary about saying that it is absolutely true color! JunoCam has a blue filter, but that blue filter has a center wavelength of 465 nm, a bit green-ward of the RGB standard of 465 nm (I think that's what it is anyway...). So blue is higher up on that ramp up from the S absorption band and sulfurous materials don't appear as dark. So features appear less yellow than they should. Green is fine. It's seems very hard for someone to mess up a green filter. But what about red? RGB standard (again I think) is around 645. The RED filter on Galileo SSI is a little long-ward at 663 nm (and the mosaic currently in use has the 756 nm filter in place of red, which wasn't taken at the time). But the RED filter on JunoCam is centered at 698 nm and is a much broader band filter, encompassing the wavelength range of SSI's 756 nm filter. Materials rich in S4 appear much more vividly red in images that use SSI 756 or JunoCam RED.
 * So what does this all mean? JunoCam isn't quite true color either. Is it closer? Honestly, this is an on going discussion among some of us scientists as we try to wrestle with JunoCam calibration, which hey, just like the arguments you all are having here, calibration is kind of important for Io... I definitely think it is closer as long as you understand the caveat the reddish materials are bit more vivid than what you would see IRL. and it has been a while since I've added to a talk page so hopefully this auto adds a signature... Volcanopele (talk) 22:11, 25 January 2024 (UTC)
 * @Volcanopele Hey there, nice to meet you. I saw your entries in the Juno website. Nice to finally finding someone IapetusCallistus (talk) 15:10, 28 January 2024 (UTC)
 * I'm all for whatever image shows more realistic color of the object. However, there are problems with Junocam and most people who process its raw data. Neither of the two images in question are close enough to reality. Galileo's image, and all those lemon yellow images are made with false color, in this case remapping unrelated bands to RGB system which have been sadly advertised by NASA's sensationalistic public relations as true color (true hue might be a better term). Indeed, NASA has a disastrous history of being honest with visual reality of its images which are made with robotic spacecraft. Sadly, that has only fueled nutters' ramblings ever since the great explosion of insanity in 2016. First public example of gross mistake was with Vikings and Martian sky which was presented as blue. Nowdays with MRO, the agency constantly pumps out false colors of Martian surface with blue, dark bluegreen, cyan and light blue features, and never even mentioning what's that all about. Images from rovers are nearly always pushed into wrong white balance to help geologists, but it does not help the laymen. Would it hurt the imagers to release proper images to the public and reserve the others for scientists? It's just this pervasive inability to understand how damaging this is to the trust of society which is increasingly uneducated and paranoid. Keep doing this in a democracy where your funding depends on public popularity and problems will occur.
 * Juno's latest images, synthesized by "citizen scientists", showed us quite vividly, through examples with Jupiter, how grossly far from reality those can get. But anything for likes on Instagram, am I right? I seriously doubt Io is a brown body without a hint of yellow. After all, it has elemental sulfur deposits on its surface. Some of it is in the typical allotropes which are yellow.
 * Attempt by the Planetary society is a very good middle ground - more towards dull brownish than lemon yellow. Lajoswinkler (talk) 14:25, 22 February 2024 (UTC)
 * Unfortunately, the one provided by the Planetary Society only covers a partial mosaic of Io's surface. We'll have to get someone to process a full-disc image of Io on our own, it looks like. I do agree that it does seem like the most color-accurate of the three provided, and it should provide a very helpful reference point to work from should anyone here decide to tackle the issue of processing Galileo imagery. ArkHyena (talk) 19:37, 22 February 2024 (UTC)

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

title: Talk:Io (moon)


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Talk:KOS-MOS

Comments/input
I figured I'd create a section for my thoughts and comments as I look over the article. Sergecross73  msg me  18:45, 14 February 2024 (UTC)

 * Meanwhile the name KOS-MOS, pronounced "cosmos"
 * I could be wrong, but I don't recall this being accurate. I'm bad at conveying pronunciations, but I think of "cosmos" being pronounced "Kahz-mose", whereas, I thought I recalled "KOS-MOS" being pronounced more like "Kose-mose". The pronunciation didn't seem to be in the source given either. The rest of the sentence was good and sourced, but I think the part above needs to be reworked or dropped. Sergecross73   msg me  18:45, 14 February 2024 (UTC)

 * I think the Reception section should be rearranged so that they scholarly, detailed sources, are mentioned more upfront in the section. I think its more important, and honestly I think it'll help dissuade people from wanting to re-merge it again. The non-scholarly stuff is fine...but its also a lot of the stuff that editors use to try to pad out non-notable character article. Just a thought. Sergecross73   msg me  19:41, 14 February 2024 (UTC)

title: Talk:KOS-MOS


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Masami Kurumada

Masami Kurumada (車田 正美) is a Japanese manga artist and writer, known for specializing in fighting manga featuring bishōnen and magical boys.

He is the founder of the manga studio Kurumada Productions or Kurumadapro for short. He achieved fame as the creator of popular manga, such as Ring ni Kakero, Fūma no Kojirō, Saint Seiya and B't X. The male characters in his works often display very masculine qualities and traits, and display courage through sacrifice, selflessness and true heroism. He has won the Best Success award with Saint Seiya and the Best Inspiration award with Ring ni Kakero.

Profile
Kurumada's first work was Otoko Raku, which earned him an award in a manga contest for aspiring manga artist, and became assistant to professional manga artists. Some time later, he debuted as a professional manga artist in 1974 with his manga Sukeban Arashi, and achieved his first hit three years later when he started writing and drawing Ring ni Kakero, which brought him recognition as a popular manga author, and lasted five years, and he considers it his favorite creation. A practicer of the martial arts in his younger days, the influence this has exerted on his various works is worthy of mention.

Also, in the same manner as many manga artists today, Kurumada employs the revered Osamu Tezuka's Star System manga technique, which is essentially resorting to the use of a stable cast of characters in his various works (characters keep the same appearance and personality, but sometimes the author gives them new names and different roles than in previous works). Because of this, the main characters of his works most of the time bear a resemblance to Takane Ryūji, the protagonist of Ring ni Kakero. The main characters of his subsequent works have almost the same appearance and personality of Ryūji, specifically Jingi Kikukawa (Otoko Zaka), Kojirō (Fūma no Kojirō), Seiya (Saint Seiya), Teppei Takamiya (B't X), Shō (Silent Knight Shō), Aoi Tendō (Aoi Tori no Shinwa), Rindō Kenzaki (Ring ni Kakero 2), among others.

Besides Kurumada, other renowned manga artists that resort to the master Tezuka's technique include legendary authors Leiji Matsumoto, Monkey Punch and Shōtarō Ishinomori or Clamp. Clamp was heavily influenced by Kurumada's works, and they began their career as manga authors creating doujinshi based on Kurumada's characters. It is also known that anime adaptations aren't much to his liking, he prefers manga. He agreed that his works Fūma no Kojirō, Saint Seiya, Ring ni Kakero and B't X were adapted to anime, to follow the long-time tradition of popular manga having an animated adaptation.

His drawing style is very classic, reminiscent from the manga/anime aesthetics more predominant in the 1960s and 1970s, albeit a constant flaw in his art is an inconsistent trace and proportion unbalance. He often draws his characters as if seen from a low perspective. His drawings can sometimes seem rough, but the improvement in his artistic technique is evident when comparing older works to more recent ones. His coloring style is almost exclusively realistic, unlike the vast majority of manga artists, who often resort to the use of non-natural colors for the hair or eyes of their characters, although with the publication of Saint Seiya Next Dimension volumes totally in color, the addition of new characters with non-natural hair colors occurs often.

Certain graphics elements characteristic of his style can be found all over his works, mostly during fight sequences, having become widely known. Fans have created terms to refer to them such as Kurumada-ochi (車田落ち), meaning "Kurumada Fall", which designates the typical head-first falling characters, and Kurumada-futtobi (車田吹っ飛び), meaning "Kurumada Launch", which refers to characters that are projected high into the air by opponents, to name a few.

Recurrent themes in his works are friendship, courage, redemption and sacrifice. Masculine virtue and qualities, honesty and honor are also traits often found in his characters. Female characters in his works mostly play a much lesser role, but several ones with key roles can also be found, such as Rei Kojinyama (Sukeban Arashi), Kiku Takane (Ring ni Kakero) and Saori Kido (Saint Seiya).

Kurumada has stated in interviews that he obtains some creative influence from yesterday's authors considered masters of the manga medium today, such as Hiroshi Motomiya, Sanpei Shirato and Mitsuteru Yokoyama. He specially considers that Motomiya's works had a very strong impact and influence on him.

Kurumada also draws inspiration from universal knowledge and folklore, such as Greek mythology, Japanese and Chinese mythology, Buddhist and Hinduist doctrine, Trascendental philosophies, and classic works of literature, such as Dante Alighieri's The Divine Comedy, and Outlaws of the Marsh, to name a few.

His interest in boxing, wrestling and martial arts is well known, and he maintains close relations with renowned personalities of those circles. As he states in his website, he likes to drink with friends and to practice photography while jogging.

Among his works that have been cancelled due to failing to attract fans: Otoko Zaka, Silent Knight Shō and Aoi Tori no Shinwa. His works that suffered popularity decrease: B't X (which he successfully concluded without facing cancellation), and Saint Seiya. In Saint Seiya's case, Kurumada was forced by Shueisha, his publisher, to finish the manga after the Hades Arc, in 1991. He put his manga in hiatus after he finished the mentioned arc, and resumed it in 2006 with Saint Seiya Next Dimension. The anime adaptation of Saint Seiya experienced a popularity decrease during the anime-only Asgard arc, while the popularity of the original manga was still strong; the anime back in 1989, was in pre-production of the episodes that would adapt the Hades arc of the manga. Because of low popularity of the anime adaptation, the project was suspended and remained so until 2003, when it was resumed and the Hades arc of the manga finally was adapted to animation. The episodes that adapted the two final volumes of the manga were aired in between May and August 2008, finally leaving Kurumada's manga completely adapted to anime.

In 2004, Kurumada celebrated 30 years as a professional manga artist, and that same year two of his older and best known works experienced a resurfacing. The original Ring ni Kakero was adapted to anime, 27 years after its manga debut, and as mentioned before, the Saint Seiya anime adaptation was resumed in 2003 and an attempt to start the Zeus Chapter was made with the release of the Saint Seiya Tenkai-Hen Josō ~Overture~ movie in 2004, which was planned to continue the story with the subsequent release of OVAs, but due to discrepancies between Kurumada and Toei Animation, the project failed and was abandoned. Kurumada still plans to publish the "Zeus Chapter", written and drawn by him, in manga form in the near future, by 2012, a considerable amount of elements from it have already been revealed by Kurumada in Saint Seiya Next Dimension and he is set to continue doing so in the next instalments of that work in the japanese summer in 2013.

Kurumada's works have had influence on manga authors and related media. Worthy of mention is Yudetamago's Kinnikuman, Hiroshi Kawamoto's Tenkū Senki Shurato, Clamp's Magic Knight Rayearth, Kōichi Tokita's Mobile Fighter G Gundam, Hajime Yatate and Ryuichi Hoshino's Yoroiden Samurai Troopers, Yoshihiro Togashi's YuYu Hakusho, videogames such as the World Heroes series and The King of Fighters series, among others. References to his works by other authors can be found in the mentioned videogames and in popular manga, such as Kōsuke Fujishima's Aa! Megami-sama, Kenjirō Hata's Hayate no Gotoku, Chika Umino's Honey & Clover, Tite Kubo's BLEACH, and their respective anime adaptations, among others.

French director Louis Leterrier has cited Kurumada and his manga Saint Seiya having a great impact on him since his youth. In 2010, Masami Kurumada was contacted by Warner Brothers to collaborate in a project for Leterrier's mythologically themed motion picture Clash of the Titans, remake of the original 1981 film. Kurumada authored promotional illustrations depicting pivotal scenes from the film. Countless are the products of merchandise(action figures, T-shirts, toys, video games, ect) relative the works of Kurumada, sold all over the worlds with great success. His fans are usually referred to as "Masamists".

Manga

His manga works listed chronologically and their duration:

One-shots

 * Mikeneko Rock (1975)
 * Mabudachi Jingi (Jingi the True Friend, 1979)
 * Shiro-Obi Taishō (White-Belt Champion, 1979)
 * Seiya ni Kane wa Naru (The Bell rings in the Sacred Night, 2021)

Books

 * Cosmo Special (1988)
 * Burning Blood (1996, artbook)
 * Honō no Tamashī (炎の魂 Fire Soul, 2000, data collection)
 * Saint Seiya Encyclopedia (2001, Artbook and character data collection)
 * Saint Seiya Sora Kurumada Masami Illustrations (2004, Artbook and issues data collection)
 * Saint Seiya : Gigantomachia (2002, a non-canonical sidestory novel written by Tatsuya Hamazaki)
 * Raimei-ni Kike (Listen in the Lightning, 2006)
 * Masami Kurumada best bout! 2 vol. (2014)
 * "Saint Seiya 30 Shunen Kinen Gashu, Seiiki - Sanctuary Artbook (2016)".

Anime adaptations of his works

 * Saint Seiya (1986 - 1989, 114 episodes).
 * Fūma no Kojirō (1989 - 1990, 12 OVA episodes).
 * B't X (1996, 25 episodes)
 * B't Neo (1997, complementary to B't X, 14 OVA episodes).
 * Ring ni Kakero 1 (2004 - 2011, 36 episodes)
 * Saint Seiya - The Hades Arc (2002 - 2008, complementary to Saint Seiya, 31 OVA episodes).
 * Saint Seiya: The Lost Canvas (2009 - 2011, animated adaptation of the alternative work of the same name, 26 OVA episodes)
 * Saint Seiya Omega (2012 - 2014, an anime original story series, 97 episodes).
 * Saint Seiya: Soul of Gold (2015, anime original story series, 13 episodes ONA).
 * Knights of the Zodiac (2019, reimagin/remake, 24 episodes)

Anime movie adaptations of his works

 * Saint Seiya: Evil Goddess Eris (1987)
 * Saint Seiya: The Heated Battle of the Gods (1988)
 * Saint Seiya: Legend of the Crimson Youth (1989)
 * Saint Seiya: Warriors of the Final Holy Battle (1989)
 * Fūma no Kōjirō: Fūma Hanran-Hen (1992)
 * Saint Seiya: Heaven Chapter − Overture (2004)
 * Saint Seiya: Legend of Sanctuary (CGI motion picture, 2014).

Live-action adaptations of his works

 * Fūma no Kojirō (TV tokusatsu drama of 13 episodes for the Fūma VS Yasha arc)
 * Saint Seiya Musical: A short-lived adaptation of the Sanctuary arc and the Poseidon arc from Kurumada's manga for the musical theatre, 1991.
 * Saint Seiya - Super Musical: A live-action adaptation of the first Saint Seiya film for the musical theatre, 2011.
 * Knights of the Zodiac: The Beginning, 2023. A japanese/american live action film, based on author Kurumada's comic book.

Spin-off works by other authors

 * Saint Seiya Episode G (2002 - 2013, commissioned by Kurumada to Megumu Okada)
 * Fūma no Kojirō : Yagyū Ansatsuchō (2003 - ??, commissioned by Kurumada to Yuri Satoshi)
 * Saint Seiya Lost Canvas (2006 - 2011, commissioned by Kurumada to Shiori Teshirogi)
 * Saint Seiya Lost Canvas Anecdotes (2011 - 2016, commissioned by Kurumada to Shiori Teshirogi)
 * Saint Seiya - Saintia Shō (2013–2021, commissioned by Kurumada to Chimaki Kuori)
 * Saint Seiya Episode G Assassin (2014 - 2019, commissioned by Kurumada to Megumu Okada)
 * Saint Seiya Episode G Requiem (2019–present, commissioned by Kurumada to Megumu Okada)
 * Kurumada Suikoden - Hero of Heroes (2014–present, commissioned by Kurumada to Yun Kōga, a manga series gathering Kurumada's most prominent protagonists, to commemorate Kurumada's 40th anniversary as a manga artist)
 * Saint Seiya: Meiō Iden – Dark Wing (2020–present, commissioned by Kurumada to Kenji Saito and Shinsu Ueda.)

Out of all of them, Saint Seiya is his most famous work in the western world but not in Japan, its popularity there is surpassed by that of Ring ni Kakero (1 and 2), which is the longest of Kurumada's works, at 51 collected volumes. Saint Seiya, is collected in 28 volumes to date, and has been resumed by Kurumada with Saint Seiya Next Dimension, the continuation to his original manga, ending the hiatus the work remained in since 1991, and to date adds thirteen more volumes to the original Saint Seiya manga, for a total or 41 volumes. The third longest is B't X, collected in 16. As stated before, Anime adaptations have been made for Saint Seiya, Fūma no Kojirō, B't X, and Ring ni Kakero, all closely follow his source manga works.

Saint Seiya videogames have been released for old consoles such as Famicom/NES, Game Boy and more recently various video games for PlayStation 2(2006-2008) and for PlayStation 3(2011), and a Saint Seiya Omega game for PSP was released in December 2012, and Saint Seiya: Brave Soldiers released in 2013 for PlayStation 3 and Saint Seiya: Soldiers' Soul released in 2015 for PlayStation 3 and PlayStation 4 and PC. Recently, Ring ni Kakero has also been the theme for Pachinko game machines, as well as Saint Seiya, on which a recently released pachinko machine is based.

Saint Seiya Myth Cloth is a successful line of figures that started in 2003 and is still in production based on the many characters of the original Saint Seiya by Kurumada.

Currently, Kurumada working on Saint Seiya Next Dimension (a prequel and continuation to his classic manga series in which Hades recalls his fight with the previous Pegasus Saint in the 18th century). It was revealed by Kurumada and Akita Shōten that Saint Seiya Next Dimension holds a canonical status in the universe of Saint Seiya, and it is also its legitimate continuation. He recently finished Ring ni Kakero 2, in 2009, after a successful run of 9 years. A live-action series of Fūma no Kojirō was released on Japanese TV. He recently started working on a new manga series Raimei-ni Kike.

He also has authorized two manga authors to write and draw sidestories for his manga Saint Seiya, specifically Saint Seiya Episode G, written and drawn by Megumu Okada, and Saint Seiya Lost Canvas, written and drawn by Shiori Teshirogi. Since these two works aren't authored by Kurumada, but only authorized and supervised by him, the events depicted in them and the characters created for them are still considered non-canonical, unlike Next Dimension which holds an official canonical status.

Kurumada had most of his works published by Shueisha, in the prestigious Shūkan Shōnen Jump manga magazine. He began publishing his works with Kadokawa Shoten, in their magazine Gekkan Shōnen Ace. In 1995 he resumed his relations with Shueisha and began publishing with them again, and his latest works and the current ones have been published by that company to date, excluding Saint Seiya Lost Canvas, published by Akita Shoten in the Weekly Shōnen Champion manga magazine, Saint Seiya Next Dimension, published in the Shōnen Ace manga magazine and Raimei-ni Kike, published by Akita Shoten in the Champion Red manga magazine.

In 2012, Kurumada revealed the upcoming anime television series, Saint Seiya Omega. Described as an anime original story, separate from Kurumada's canon, the series will take place 25 years after the events in Kurumada's Saint Seiya manga. The series began airing in April that year, and has been renewed for a second season that started in April 2013.

In 2014 Masami Kurumada was the executive producer of a CGI remake of the Sanctuary chapter called Saint Seiya: Legend of Sanctuary.

In 2016, marking 30 years since the original release of the Saint Seiya manga, two commemorative exhibitions were held in Tokyo and Hong Kong in which numerous commemorative merchandising products related to Saint Seiya were also sold.

For the 2017 season, Masami Kurumada has designed and collaborated on the Japanese baseball team shirt 広島東洋カープ "Hiroshima Toyo carp"

In 2019, a new animated adaptation of Kurumada's original Saint Seiya manga, is started to be created by Toei Animation and Netflix, is published worldwide on the same platform. The series is made in CGI.

A Live Action film based on the original Saint Seiya by Masami Kurumada has been announced. However, the release date have not been revealed.

Chinese Tencent has announced that it will produce live-action series TV of Saint Seiya by Masami Kurumada, the release date it has not been made known.

June 2019 in Taiwan there was an exhibition on the works of the master Masami Kurumada, with very many drawings drawn from his works and also various armor taken from his Saint Seiya manga, all reconstructed in natural scale on a 1: 1 scale.

Songs
Masami Kurumada wrote the lyrics to many of the songs used in the anime adaptations of his manga series. A CD compiling the songs was released in December 2005 with an extra song to Otoko Zaka, the CD is called Kurumada: The Complete Works.

The following songs are included:
 * 01. いかなる星の下に〜We're fearless warriors〜
 * 02. 星よ流れるな〜Stop the fate〜
 * 03. 少年記 I〜Burning Blood〜
 * 04. 少年記 II〜Leave my heart〜
 * 05. 風の戦士
 * 06. あの日風の中で・・・
 * 07. 君を守りたい
 * 08. 信じる心
 * 09. 光を探して
 * 10. いつか聞いた風の歌
 * 11. 風に向かって走れ〜standing & fight〜
 * 12. 名も無き野の花〜fulfill your dream〜
 * 13. 純情ケンカチャンピオン〜one way boy〜
 * 14. いばらの旋律〜Melody〜
 * 15. 覇道のディスタンス〜Distance〜
 * 16. ｢明日への闘志｣
 * 17.男坂

After the CD was released Kurumada wrote the lyrics to the intro and ending song of the credits sequence of the 'Inferno' stage of the Hades arc of the Saint Seiya anime adaptation (Episodes 128 to 145).

 * "Megami no Senshi, Pegasus Forever"
 * "Takusu mono he ~ My Dear"

Also, he wrote the lyrics to the ending theme of the second season of the Ring ni Kakero 1 anime adaptation, in 2006:

 * Shining like Gold 〜思い出の欠片〜 (Omoide no kakera)

For the final episodes that completed the adaptation of the Hades arc of his Saint Seiya manga to anime, a new song for the credits roll was composed with Kurumada authoring the lyrics. The episodes aired in mid 2008.

 * "Kami no Sono - Del Regno"

Also, Kurumada had a short role as a voice actor in the anime adaptation of his manga Ring ni Kakero. He appeared in the first episode, as himself and as the ''Jitsuroku! Shinwakai'' protagonist, who shares his name, and he provided his voice to both.

Continuing his contributions as lyricist, Kurumada wrote the lyrics to the ending theme of the first and second season of the Saint Seiya: The Lost Canvas anime:

 * "Hana no Kusari"

Additionally, the release of a new CD containing the rest of songs with lyrics authored by Kurumada for the anime adaptations of his works Saint Seiya and Ring ni Kakero, is set for 2013. The compilation is titled "Kurumada: The Complete Works 2" and includes some previously released material. The songs included in the CD:

 * 01. 明日 へ の 闘志
 * 02. 思い出 の 欠片 ~Shining like gold~
 * 03. 誓い の 時 ~Strike anywhere~
 * 04. 明日 へ の 飛翔 ~Flap your wings~
 * 05. 拳 よ 空 翔けろ ~Rough and ready~
 * 06. 虹 の 彼方
 * 07. 女神 の 戦士 ~Megami no Senshi~
 * 08. 託す 者 へ ~My Dear~
 * 09. 神 の 園 ~Del Regno~
 * 10. 花 の 鎖 ~Hana no kusari~

title: Masami Kurumada