Pillan Patera is a

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

, or a complex crater with scalloped edges, on

Jupiter Jupiter is the fifth planet from the Sun and the List of Solar System objects by size, largest in the Solar System. It is a gas giant with a mass more than two and a half times that of all the other planets in the Solar System combined, but ...

's moon Io. It is located at , south of Pillan Mons and west of Reiden Patera. It is named after the

Araucanian The Mapuche ( (Mapuche & Spanish: )) are a group of indigenous inhabitants of south-central Chile and southwestern Argentina, including parts of Patagonia. The collective term refers to a wide-ranging ethnicity composed of various groups who sh ...

thunder, fire, and volcano god. Its name was approved by the

International Astronomical Union The International Astronomical Union (IAU; french: link=yes, Union astronomique internationale, UAI) is a nongovernmental organisation with the objective of advancing astronomy in all aspects, including promoting astronomical research, outreac ...

in 1997. Pillan Patera is approximately 70 kilometers in diameter. In the summer of 1997, it erupted in an event now defined as "Pillanian" eruption style. At temperatures higher than 1,600 °C, (2912 °F) a 140 kilometer high plume eruption deposited dark

pyroclastic Pyroclastic rocks (derived from the el, πῦρ, links=no, meaning fire; and , meaning broken) are clastic rocks composed of rock fragments produced and ejected by explosive volcanic eruptions. The individual rock fragments are known as pyroc ...

materials rich in orthopyroxene over an area greater than 125,000 km². This was followed by the emplacement of over 3,100 km² in dark flow-like material north of the

caldera A caldera ( ) is a large cauldron-like hollow that forms shortly after the emptying of a magma chamber in a volcano eruption. When large volumes of magma are erupted over a short time, structural support for the rock above the magma chamber is ...

. The high temperature part of the eruption lasted from 52 to 167 days and between May and September 1997, with peak eruption temperatures around June 28, 1997. The 1997 eruption was the largest

effusive eruption An effusive eruption is a type of volcanic eruption in which lava steadily flows out of a volcano onto the ground. Overview There are two major groupings of eruptions: effusive and explosive. Effusive eruption differs from explosive eruption, ...

ever witnessed. During a 100-day period, at least 31 km³ of lava were erupted, with 25 km³ shortly afterward. The eruption sheds light on emplacement of very large, voluminous flows millions of years ago on

Mars Mars is the fourth planet from the Sun and the second-smallest planet in the Solar System, only being larger than Mercury (planet), Mercury. In the English language, Mars is named for the Mars (mythology), Roman god of war. Mars is a terr ...

and

Earth Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's surfa ...

. The highest effusion rates exceeded 10,000 cubic meters per second. The eruption produced a large, dark, deposit, 400 kilometers in diameter, which surrounds Pillan and partially covers a bright red ring left by the volcano Pele's plume. Since the eruption, the Pillan plume deposit has faded, coated by material from Pele and Kami-Nari Patera, a small volcano to the east of Pillan Patera.

References

{{Io Volcanoes of Io (moon) Active volcanoes