By Chris Deziel | Updated Mar 24, 2022
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On Earth, sunlight powers the wind. On Neptune, however, the sun is almost a distant star, yet the planet boasts the solar system’s most intense surface winds. The driving force? Neptune’s own internal heat.
Compared to Earth's calm skies, the gas giants are stormy. Jupiter’s Great Red Spot can reach 618 km/h (384 mph), nearly double the speed of the fiercest terrestrial hurricane. Saturn’s upper‑atmosphere winds soar to 1,800 km/h (1,118 mph), almost triple Jupiter’s. Neptune tops the chart: its Great Dark Spot accelerates to 1,931 km/h (1,200 mph).
All three ice giants—Jupiter, Saturn, and Neptune—emit more energy than they receive from the Sun. For Jupiter, the surplus originates from leftover heat of formation. Saturn’s excess stems from friction generated by helium rain. Neptune, surrounded by a methane‑rich blanket that traps heat, radiates 2.7 times the solar energy it absorbs, despite its frigid temperatures. This excess heat powers the planet’s fierce winds.
