Tupan Patera is an active

volcano A volcano is commonly defined as a vent or fissure in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface. On Earth, volcanoes are most oft ...

on Jupiter's

moon The Moon is Earth's only natural satellite. It Orbit of the Moon, orbits around Earth at Lunar distance, an average distance of (; about 30 times Earth diameter, Earth's diameter). The Moon rotation, rotates, with a rotation period (lunar ...

Io. It is located on Io's anti-Jupiter hemisphere at . Tupan consists of a volcanic crater, known as a ''

patera In the material culture of classical antiquity, a ''patera'' () or ''phiale'' ( ) is a shallow ceramic or metal libation bowl. It often has a bulbous indentation ('' omphalos'', "belly button") in the center underside to facilitate holding it, ...

,'' 79 kilometers across and 900 meters deep. The volcano was first seen in low-resolution observations by the two '' Voyager'' spacecraft in 1979, but volcanic activity was not seen at this volcano until June 1996 during the ''

Galileo Galileo di Vincenzo Bonaiuti de' Galilei (15 February 1564 – 8 January 1642), commonly referred to as Galileo Galilei ( , , ) or mononymously as Galileo, was an Italian astronomer, physicist and engineer, sometimes described as a poly ...

'' spacecraft's first orbit. Following this first detection of near-infrared thermal emission and subsequent detections by Galileo during the next few orbits, this volcano was formally named Tupan Patera, after the thunder god of the

Tupí Tupí, also known as ''formatge de tupí'', is a fermented cheese of a certain area of the Pyrenees and Pre-Pyrenees made from cows' or sheep's milk. It is a cheese traditionally prepared in the mountainous Pallars region, as well as in the Cerdan ...

- Guaraní

indigenous peoples in Brazil Indigenous peoples in Brazil or Native Brazilians () are the peoples who lived in Brazil before European contact around 1500 and their descendants. Indigenous peoples of the Americas, Indigenous peoples once comprised an estimated 2,000 distric ...

, by the

International Astronomical Union The International Astronomical Union (IAU; , UAI) is an international non-governmental organization (INGO) with the objective of advancing astronomy in all aspects, including promoting astronomical research, outreach, education, and developmen ...

in 1997. Additional observations by Galileo's Near-Infrared Mapping Spectrometer (NIMS) between 1996 and 2001 revealed Tupan to be a persistently active volcano, visible during most NIMS observations of Io's anti-Jupiter hemisphere. Galileo acquired high-resolution color images and near-infrared spectra of Tupan Patera during an encounter on October 16, 2001. This data revealed warm, dark silicate lava on the eastern and western sides of the patera floor with an "island" of bright, cool material in the middle. Reddish material was observed along the margins of the bright island as well as on the bright plains to the southeast of the volcano. This is indicative of short-chain

sulfur Sulfur ( American spelling and the preferred IUPAC name) or sulphur ( Commonwealth spelling) is a chemical element; it has symbol S and atomic number 16. It is abundant, multivalent and nonmetallic. Under normal conditions, sulfur atoms ...

being emitted from vents on the patera floor by recent volcanic activity. The island as well as a shelf of material at the base of the patera wall is outlined by a "strand" of dark material. This strand line may result from lava filling the patera floor, then deflating due to either degassing of the cooling lava or drainage back into the magma chamber. Alternatively, the strand line may have been created from limited volcanic activity along the edge of the patera floor. The mix of red-orange and dark material on the volcano's western side possibly resulted from sulfur melting from the central island and the patera wall and covering the dark material in this area. This theory is supported by the cooler temperatures seen on the western side of Tupan, cool enough perhaps to support the melting and solidification of sulfur, compared to the much darker eastern side. The morphology of Tupan Patera may also be consistent with a sill that is still exhuming itself. After the last ''Galileo'' flyby of Io in January 2002, Tupan remained active with observations of a thermal emission from the volcano by ground-based observers using the Keck Telescope and by the ''

New Horizons ''New Horizons'' is an Interplanetary spaceflight, interplanetary space probe launched as a part of NASA's New Frontiers program. Engineered by the Johns Hopkins University Applied Physics Laboratory (APL) and the Southwest Research Institut ...

'' spacecraft. A large eruption at Tupan was observed by astronomers using the 10-meter

adaptive optics Adaptive optics (AO) is a technique of precisely deforming a mirror in order to compensate for light distortion. It is used in Astronomy, astronomical telescopes and laser communication systems to remove the effects of Astronomical seeing, atmo ...

at the Keck Observatory on March 8, 2003. Other than this major eruption, activity at Tupan through the ''Galileo'' mission and afterward has been persistent, with variations in power output from the patera floor being episodic, similar to, but at lower energy levels, Loki Patera.

References

{{Io Volcanoes of Io (moon) Active volcanoes