One of the biggest volcanic eruptions in the solar system yet seen was at its hottest 25 years ago today. The peak temperature reached almost 3,000 degrees Fahrenheit — far hotter than any eruption ever seen on Earth.

Pillan Patera is on Io, a moon of Jupiter. Io is about the same size as our own moon. But while the Moon is pretty much dead, Io is the most active body in the solar system, with hundreds of active volcanoes. They’re powered by a gravitational tug-of-war between Jupiter and some of its other moons, which melts the rock below Io’s surface. The molten rock forces its way out through giant volcanoes.

Pillan Patera is one of Io’s bigger volcanoes — 45 miles wide. And from about May to September of 1997, it staged a massive eruption. The plume of ash climbed about 90 miles high. As the ash fell back, it covered an area as big as Iowa.

Pillan Patera also belched hot lava — enough every minute to fill the Empire State Building. The lava eventually covered an area twice the size of Rhode Island, creating a huge dark spot.

The volcano hasn’t done much since then. In fact, the lava field has just about disappeared — paved over by other volcanoes on this active moon.

Jupiter is high in the southeast at dawn, and looks like a bright star. Binoculars reveal its four largest moons, which look like tiny stars near the planet. The quartet includes Io — a small world with a volcanic attitude.
 

Script by Damond Benningfield

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