NASA’s Juno dives into Jupiter’s wild winds and probes Io’s magma-filled crust

This composite image, derived from data collected in 2017 by the JIRAM instrument aboard NASA’s Juno, shows the central cyclone at Jupiter’s north pole and the eight cyclones that encircle it. Data from the mission indicates these storms are enduring features. (Image: NASA)

For years, we’ve stared at Jupiter and wondered. Now, thanks to NASA’s Juno spacecraft, some of those mysteries are becoming clearer. From fierce winds near its north pole to lava bubbling beneath Io’s surface, the gas giant continues to surprise.

Fierce Jet Streams and Cold Cyclones

NASA’s Juno mission has gathered new data from Jupiter. This includes updates from the planet’s cloudy atmosphere and its volcanic moon, Io. The results were shared in Vienna on April 29 during the European Geosciences Union General Assembly.

Juno's findings show stronger jet streams circling Jupiter’s north. Scientists created a new model to study these winds. It also revealed Jupiter's cold polar cap is 11 degrees cooler. Winds there reach speeds of over 100 mph (161 kph).

Juno uses radio occultation to study Jupiter’s atmosphere. This technique measures how radio waves bend in the planet's layers. So far, 26 such soundings have been completed. They help scientists understand temperature and density patterns in the upper atmosphere.

At the planet’s north pole, a large cyclone dominates. It is surrounded by eight smaller cyclones moving slowly. These are not like Earth’s hurricanes, which stay in warmer zones. On Jupiter, these storms gather near the poles and stay active for years.

NASA's #JunoMission gets under Io's skin: New data from our Jovian orbiter reveals volcanic action on Jupiter's moon Io (seen here in infrared) and also sheds light on the fierce winds and cyclones of Jupiter's atmosphere. https://t.co/kmKvWzEhaf pic.twitter.com/Qcm2LPUUA5
NASA Solar System (@NASASolarSystem) April 29, 2025

“These forces keep the whole group stable,” said Yohai Kaspi from Israel’s Weizmann Institute. “The cyclones also drift westward in a slow, circular pattern.”

Hot Lava Beneath Io’s Surface

Juno’s instruments are also watching Io, a volcanic moon. Using its microwave radiometer and infrared mapper, the team discovered something new. They found slowly cooling lava just under the moon’s crust.

“About 10% of Io’s surface has cooling lava,” said Shannon Brown of NASA’s Jet Propulsion Laboratory. “We saw this across all longitudes and latitudes.”

These lava fields work like a car radiator. Heat from the interior moves to the surface and escapes. This gives scientists insight into how Io renews its surface.

Juno’s data also caught the most energetic eruption in Io’s history. Detected during a flyby on December 27, 2024, the eruption continued into March. It’s still active now, and more updates may come on May 6. That’s when Juno will pass just 89,000 kilometres from Io.

More Discoveries Await

Juno’s orbit keeps changing, letting it see new places. The spacecraft is also flying through powerful radiation belts. Despite the risks, the team is eager to learn more.

“Jupiter has huge storms, strong winds and volcanic moons,” said Scott Bolton of the Southwest Research Institute. “We built Juno like a tank, and it’s doing its job.”

The Juno mission is led by NASA’s Jet Propulsion Laboratory in California. The project is part of NASA’s New Frontiers Program. Lockheed Martin built the spacecraft, while the Italian Space Agency helped fund one of its instruments.

As Juno dives deeper into Jupiter’s secrets, it shows us just how wild our solar system can be.