Astronomers in Hawaii observed a volcanic eruption some 400 million miles away from earth on Jupiter's moon Io; the event is one of the most massive eruptions ever recorded on the solar system's most volcanically active body, according to New Scientist.

The observation was made Aug. 15 using the Keck II telescope on Hawaii's Mauna Kea, a volcano itself. Astronomers observed jets of molten rock blasting hundreds of miles into the air, covering an area of 11.5 square miles.

Ashley Davies of NASA's Jet Propulsion Laboratory in California said the observation would easily rank in the top 10 of all the eruptions ever observed on Io. The immense nature of the eruption made it easy for astronomers to spot.

"We try to look at Io at every opportunity, in the hope of seeing something like this," Davies told New Scientist earlier this month. "This time we got lucky."

Dr. Imke de Pater, Professor of Astronomy and of Earth and Planetary Science at the University of California in Berkeley, is credited with discovering the eruption, which took place in Io's Rarog Patera region, which is named after a Czech fire god.

"It is a very energetic eruption that covers over a 30 square kilometer area," she told Universe Today. "For Earth, that is big, and for Io it is very big too. It really is one of the biggest eruptions we have seen."

A 2011 eruption in Io's Surt region is considered the biggest ever observed on the moon, de Pater said.

"For this one, the total energy is less but per square meter, it is bigger than the one in 2001, so it is very powerful."

Io, the innermost of the four largest moons around Jupiter, has about 240 volcanically active regions, more than any other object in the solar system. Yet strangely, the Rarog Patera region has no other documented eruptions, a fact the research team finds interesting, Universe Today reported.

Because Io has virtually no atmosphere and relatively low gravity, volcanic eruptions there reach much greater heights than those here on Earth, according to New Scientist.

Blasts on Io are also supremely intense. A single eruption can unleash 5 terawatts of energy.

"It's an astonishing amount of energy," said NASA's Davies. "Io is this wonderful volcanic laboratory."