Jupiter's Great Red Spot is a colossal storm whose immense scale is hard to fathom. Beyond its vast width, new data shows it's far deeper than scientists anticipated.
Nestled between two jet streams flowing in opposite directions, which drive its counterclockwise spin, the Great Red Spot has raged for over 400 years. Measuring about 16,000 km wide, it's the Solar System's largest atmospheric vortex. NASA's Juno spacecraft, orbiting Jupiter since 2016, has now enabled precise depth estimates. These findings anchor a study published in the journal Science.
Led by Dr. Marzia Parisi, the team analyzed Juno's orbital speed variations as it flew over the storm. Gravitational anomalies from denser atmospheric layers subtly shifted the probe's path, revealing the vortex's structure.
The data pinpointed the storm's depth at about 500 kilometers—tens of kilometers deeper than prior models. That's deeper than the International Space Station orbits above Earth.
The encircling jet streams plunge six times deeper than the spot's roots and race at up to 350 km/h, sustaining the vortex. Yet these depth disparities deepen the enigma of Jupiter's storm dynamics.
The Great Red Spot is shrinking: in the 1800s, it spanned four Earth diameters; by Voyager 2's 1979 flyby, twice that; today, just 1.3 times Earth's width. It may eventually vanish.
Juno's mission, with its elongated orbits, has been extended to 2025. Upcoming passes over the north pole will probe polar cyclones, while new flybys of Io and Europa loom.
