Jupiter has some of the most distinctive atmospheric features in the solar system. Jupiter's Great Red Spot is large enough to surround the Earth and is almost as famous as some of the rivers and mountains on Earth we call home. However, like Earth, Jupiter is ever-changing, and there is still much we still need to learn about this planet. NASA's James Webb Space Telescope is unraveling some of these mysteries, revealing new features of Jupiter we've never seen before, including high-speed jets racing high above the planet's equator.

Narrow jets near Jupiter's equator have wind speeds of 320 miles per hour. This image of Jupiter from NASA's James Webb Space Telescope's Near Infrared Camera (NIRCam) shows the magnificent planet in stunning detail in infrared light. In this image, brightness represents height. The numerous bright white "spots" and "stripes" are likely cloud tops condensed by high-altitude convective storms. Auroras, shown in red in this image, extend high into the sky above the Earth's north and south poles. In contrast, the dark band north of the equator has almost no cloud cover. Source: NASA, ESA, CSA, STScI, Ricardo Hueso (UPV), Imkede Pater (UC Berkeley), Thierry Fouchet (Paris Observatory), Leigh Fletcher (University of Leicester), Michael H. Wong (UC Berkeley), Joseph DePasquale (STScI)

While the jet isn't as intuitive or awe-inspiring as some of Jupiter's other features, it has given researchers an incredible understanding of how the layers of Jupiter's atmosphere interact with each other, and how the Webb telescope can help with these studies in the future.

Researchers using NASA's James Webb Space Telescope's Near Infrared Camera (NIRCam) discovered high-speed jets above Jupiter's equator, above the main clouds. At a wavelength of 2.12 microns, about 12-21 miles (20-35 kilometers) above Jupiter's clouds, the researchers found several wind shears, regions where wind speed changes with altitude or distance, which allowed them to track the jets. This image highlights several features around Jupiter's equator that are very clearly disturbed by the motion of the jets between one rotation of Jupiter (10 hours). Source: NASA, ESA, CSA, STScI, Ricardo Hueso (UPV), Imkede Pater (UC Berkeley), Thierry Fouchet (Paris Observatory), Leigh Fletcher (University of Leicester), Michael H. Wong (UC Berkeley), Joseph DePasquale (STScI)

Webb Space Telescope discovers new features of Jupiter's atmosphere

NASA's James Webb Space Telescope has discovered a new, never-before-seen feature in Jupiter's atmosphere. This high-speed jet is more than 3,000 miles (4,800 kilometers) wide and sits above the main clouds above Jupiter's equator. The discovery of this jet sheds light on how the layers of Jupiter's famously turbulent atmosphere interact with each other, and how the Webb telescope uniquely tracks these features.

Ricardo Hueso of the University of the Basque Country in Bilbao, Spain, is the first author of a paper describing the discovery. "The haze in Jupiter's atmosphere, which we always thought was a blur, now appears to be a clear feature that we can track as Jupiter spins rapidly."

Weber's unique imaging capabilities

The team analyzed data taken by Webb's Near Infrared Camera (NIRCam) in July 2022. The Early Release Science Initiative, co-led by Imkede Pater of the University of California, Berkeley, and Thierry Fouchet of the Observatory of Paris, aims to take images of Jupiter using four different filters, each capable of detecting small characteristic changes in Jupiter's atmosphere at different heights, taken at intervals of 10 hours, or one Jupiter day.

Jupiter's atmosphere is layered, and this illustration shows how the Webb telescope is uniquely able to collect information from higher levels of the atmosphere than before. Scientists were able to use the Webb telescope to determine wind speeds in different layers of Jupiter's atmosphere, allowing them to isolate high-speed jets. The observations of Jupiter were carried out under three different filters, 10 hours apart, which is one Jupiter day. Each filter can detect small characteristic changes at different heights in Jupiter's atmosphere. Source: NASA, ESA, CSA, STScI, Ricardo Hueso (UPV), Imkede Pater (UC Berkeley), Thierry Fouchet (Paris Observatory), Leigh Fletcher (University of Leicester), Michael H. Wong (UC Berkeley), Andi James (STScI)

"While the Jupiter system's changing weather patterns have been observed by various ground-based telescopes, spacecraft such as NASA's Juno and Cassini, and NASA's Hubble Space Telescope, the Webb telescope has provided new discoveries about Jupiter's rings, moons, and its atmosphere," de Pater noted.

contrasting atmosphere

Although Jupiter is different from Earth in many ways—Jupiter is a gas giant while Earth is a temperate rocky world—both planets have layered atmospheres. Observations in infrared, visible, radio and ultraviolet wavelengths from these other missions probed the lower and deeper layers of Jupiter's atmosphere - where giant storms and ammonia ice clouds reside.

On the other hand, the Webb telescope's near-infrared wavelength range is farther than before, and it is sensitive to the upper layers of the atmosphere, about 15-30 miles (25-50 kilometers) above Jupiter's cloud tops. In near-infrared imaging, high-altitude clouds and fog often appear blurred, and the brightness in the equatorial region is enhanced. With the Webb telescope, finer details can be resolved in the bright hazy wavelengths.

This illustration of lightning, convective turrets (thunderheads), deep water clouds, and clearings in Jupiter's atmosphere was based on data collected by the Juno spacecraft, the Hubble Space Telescope, and the Gemini Observatory. Juno detects radio signals produced by lightning discharges. Because radio waves can pass through all of Jupiter's clouds, Juno can detect lightning deep within the clouds as well as on Jupiter's dayside. Hubble can detect sunlight reflected by clouds in Jupiter's atmosphere. Different wavelengths of sunlight can penetrate clouds to different depths, allowing researchers to determine the relative heights of cloud tops. Gemini mapped the thickness of cold clouds that block thermal infrared light from the warmer atmosphere below the clouds. Thick clouds appear dark on an infrared map, while clear clouds appear bright. Comprehensive observations can be used to draw three-dimensional cloud structure maps and infer details of atmospheric circulation. Thick, towering clouds form where moist air rises (upwelling and active convection). Clear skies form when drier air sinks (sinks). The clouds pictured here are five times taller than similar convective towers in Earth's relatively shallow atmosphere. The area shown horizontally spans one-third of the continental United States. Source: NASA, ESA, M.H. Wong (UC Berkeley), A. James and M.W. Carruthers (STScI)

The newly discovered jet has a speed of about 320 miles (515 kilometers) per hour, twice the sustained wind speed of a Category 5 hurricane on Earth. It is located about 25 miles (40 kilometers) above Jupiter's lower stratospheric clouds (see image above).

By comparing the high-altitude winds observed by Webb with the deep winds observed by Hubble, the team was able to measure how quickly the winds change with altitude and how quickly wind shear is produced.

While Webb's superb resolution and wavelength coverage allowed it to detect the small cloud features used to track jets, supplemental observations by Hubble a day after Webb's observations were also critical for determining the basic state of Jupiter's equatorial atmosphere and for observing the development of convective storms at Jupiter's equator that are not related to jets.

"We knew that the different wavelengths of Webb and Hubble would reveal the three-dimensional structure of the storm clouds, but we were also able to use the timing of the data to see how quickly the storm developed," added Michael Wong of the University of California, Berkeley, who led the associated Hubble observations.

Future Observations and Implications

The researchers look forward to conducting more observations of Jupiter with the Webb telescope to determine whether the speed and height of the jets have changed over time.

"The wind and temperature patterns in Jupiter's equatorial stratosphere are complex but repeatable," explained team member Leigh Fletcher from the University of Leicester in the UK. "If the intensity of this new jet is related to oscillation patterns in the stratosphere, we might expect the jet to change significantly over the next two to four years - it will be very exciting to test this theory in the coming years."

Fletcher continued, "It's amazing to me that after many years of tracking its clouds and winds by numerous observatories, we still have so much more to learn about Jupiter, and that features like these jets will remain hidden until these new NIRCam images are taken in 2022."

The researchers' findings were recently published in Nature Astronomy.