Pillan Patera is a patera, or a complex crater with scalloped edges, on Jupiter

Jupiter

Jupiter is the fifth planet from the Sun and the largest planet within the Solar System. It is a gas giant with mass one-thousandth that of the Sun but is two and a half times the mass of all the other planets in our Solar System combined. Jupiter is classified as a gas giant along with Saturn,...

's moon Io

Io (moon)

Io ) is the innermost of the four Galilean moons of the planet Jupiter and, with a diameter of , the fourth-largest moon in the Solar System. It was named after the mythological character of Io, a priestess of Hera who became one of the lovers of Zeus....

. It is located at 12.34°S 243.25°W, south of Pillan Mons and west of Reiden Patera

Reiden Patera

Reiden Patera is a volcanic feature on Jupiter's moon Io. It was first detected by the Galileo SSI Team during the spacecraft Galileo's first orbit around Jupiter, initially detected as a hotspot. It was once thought that the activity there had stopped or waned below the limits of the spacecraft's...

. It is named after the Araucanian thunder, fire, and volcano god. Its name was approved by the International Astronomical Union

International Astronomical Union

The International Astronomical Union IAU is a collection of professional astronomers, at the Ph.D. level and beyond, active in professional research and education in astronomy...

 in 1997.

Pillan Patera is approximately 73 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 flow

A pyroclastic flow is a fast-moving current of superheated gas and rock , which reaches speeds moving away from a volcano of up to 700 km/h . The flows normally hug the ground and travel downhill, or spread laterally under gravity...

 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

Caldera

A caldera is a cauldron-like volcanic feature usually formed by the collapse of land following a volcanic eruption, such as the one at Yellowstone National Park in the US. They are sometimes confused with volcanic craters...

. 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

Effusive eruption

An effusive eruption is a volcanic eruption characterized by the outpouring of lava onto the ground...

 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

Mars is the fourth planet from the Sun in the Solar System. The planet is named after the Roman god of war, Mars. It is often described as the "Red Planet", as the iron oxide prevalent on its surface gives it a reddish appearance...

 and Earth

Earth

Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...

. 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

Pele (volcano)

Pele is an active volcano on the surface of Jupiter's moon Io. It is located on Io's trailing hemisphere at A large, tall volcanic plume has been observed at Pele by various spacecraft starting with Voyager 1 in 1979, though it has not been persistent. The discovery of the Pele plume on March...

'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.