Hurricane three times size of Earth behind Jupiter’s heat

Boston University research discovers Great Red Spot drives unusually hot atmosphere

Nasa's Juno spacecraft completed a five-year journey to Jupiter with a do-or-die engine burn that looped it into orbit to probe the origins of the biggest planet in our solar system.

Jupiter's hotspot is hotter than we knew. New research shows that the high temperatures in Jupiter's atmosphere are driven by the Great Red Spot on the planet's surface.

Researchers led by Dr James O'Donoghue at Boston University were trying to explain the heat in Jupiter's atmosphere, which is too high to be caused just by solar heat alone. They found that the temperatures were especially high directly above the Great Red Spot.

"The Great Red Spot is a large hurricane in Jupiter about three times the size of the Earth, at least 150 years old, likely thousands of years old," says Kevin Nolan, lecturer at IT Tallaght and Irish representative of The Planetary Society.

Inside the spot, the winds rise up to 650 km/hour (about 400 mph) and take six days to complete a spin.

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There are several big mysteries surrounding the Great Red Spot, says Mr Nolan, some of which could be relevant to events taking place on Earth.

The researchers measured the temperature on Jupiter’s surface and found that the temperatures recorded were much higher than expected given its great distance from the sun. Also temperatures were not evenly distributed across the planet’s surface.

“We could see almost immediately that our maximum temperatures at high altitudes were above the Great Red Spot far below – a weird coincidence or a major clue?”, Dr O’Donoghue said.

The researchers then identified the source of heat as acoustic waves coming from the storm in the Great Red Spot, publishing their findings on Wednesday in the journal Nature.

“Some resonant mechanism is happening and the atmosphere is literally wobbling. The energy is dissipating mechanically through the atmosphere, heating it,” Mr Nolan said.

In spite of being a gas giant, Jupiter’s climate and the mechanisms behind its weather generation are very similar to those of Earth. Gaining insight into Jupiter’s atmosphere could be relevant for terrestrial weather events.

There are a lot of unanswered questions about Jupiter’s Great Red Spot.

“We don’t know why it’s so big and so old, and we don’t know why it’s red,” Mr Nolan said.

“When we do know, that would give us a huge insight into the chemistry of Jupiter’s atmosphere. And this paper could be instrumental in providing that.”

Mr Nolan pointed out that studying Jupiter’s atmosphere and chemical composition is one of the main reasons the Juno satellite mission has been sent there. “Hopefully this will start unlocking other mysteries about Jupiter.”

Vanesa Martinez is on placement at The Irish Times under the BSA/SFI media fellowship programme