NASA’s Webb Discovers New Feature in Jupiter’s Atmosphere

Narrow jet stream near equator has winds traveling 320 miles per hour NASA’s James Webb Space Telescope has discovered a new, never-before-seen feature in Jupiter’s atmosphere. The high-speed jet stream, which spans more than 3,000 miles (4,800 kilometers) wide, sits over Jupiter’s equator above the main cloud decks. The discovery of this jet is giving […]

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Oct 19, 2023 - 21:00

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NASA’s Webb Discovers New Feature in Jupiter’s Atmosphere

Narrow jet stream near equator has winds traveling 320 miles per hour

NASA’s James Webb Space Telescope has discovered a new, never-before-seen feature in Jupiter’s atmosphere. The high-speed jet stream, which spans more than 3,000 miles (4,800 kilometers) wide, sits over Jupiter’s equator above the main cloud decks. The discovery of this jet is giving insights into how the layers of Jupiter’s famously turbulent atmosphere interact with each other, and how Webb is uniquely capable of tracking those features.

Image: Webb’s View of Jupiter

Jupiter dominates the black background of space. The image is a composite, and shows Jupiter in enhanced color, featuring the planet’s famous Great Red Spot, which appears white with light pink around the edges. The planet is striated with swirling horizontal stripes of green, periwinkle, light pink, and cream. Horizontally across the equator is a wide cream-colored band, whose height extends about 1/7 of the planet. This is the planet’s equatorial zone. The stripes across the planet interact and mix at their edges. Along both of the northern and southern poles, the planet glows in green. Bright red auroras glow just above the planet’s surface at both poles.

This image of Jupiter from NASA’s James Webb Space Telescope’s NIRCam (Near-Infrared Camera) shows stunning details of the majestic planet in infrared light. In this image, brightness indicates high altitude. The numerous bright white ‘spots’ and ‘streaks’ are likely very high-altitude cloud tops of condensed convective storms. Auroras, appearing in red in this image, extend to higher altitudes above both the northern and southern poles of the planet. By contrast, dark ribbons north of the equatorial region have little cloud cover.

Image: NASA, ESA, CSA, STScI, R. Hueso (University of the Basque Country), I. de Pater (University of California, Berkeley), T. Fouchet (Observatory of Paris), L. Fletcher (University of Leicester), M. Wong (University of California, Berkeley), J. DePasquale (STScI)

“This is something that totally surprised us,” said Ricardo Hueso of the University of the Basque Country in Bilbao, Spain, lead author on the paper describing the findings. “What we have always seen as blurred hazes in Jupiter’s atmosphere now appear as crisp features that we can track along with the planet’s fast rotation.”

The research team analyzed data from Webb’s NIRCam (Near-Infrared Camera) captured in July 2022. The Early Release Science program – jointly led by Imke de Pater from the University of California, Berkeley and Thierry Fouchet from the Observatory of Paris – was designed to take images of Jupiter 10 hours apart, or one Jupiter day, in four different filters, each uniquely able to detect changes in small features at different altitudes of Jupiter’s atmosphere.

“Even though various ground-based telescopes, spacecraft like NASA’s Juno and Cassini, and NASA’s Hubble Space Telescope have observed the Jovian system’s changing weather patterns, Webb has already provided new findings on Jupiter’s rings, satellites, and its atmosphere,” de Pater noted.

While Jupiter is different from Earth in many ways – Jupiter is a gas giant, Earth is a rocky, temperate world – both planets have layered atmospheres. Infrared, visible, radio, and ultraviolet light wavelengths observed by these other missions detect the lower, deeper layers of the planet’s atmosphere – where gigantic storms and ammonia ice clouds reside.

Image: Jupiter’s Equatorial Jet Stream

The infographic shows Webb’s image of Jupiter at the left. The planet is striated with swirling horizontal stripes of neon turquoise, periwinkle, and cream. Below the planet, the NIRCam filters and their respective colors assigned are listed – F164N in blue, F212N in green, and F360M in red. On the right side of the infographic, there are 8 separate images. Two of those images are horizontal and span the entire right half of the infographic. The top horizontal image is labeled F212N 10:52 UT and the bottom is labeled F212N 20:55 UT. They are zoomed-in pullouts from a section of Jupiter’s equator—outlined in a white box on the image of the planet on the left. Both of these images are white and grey with horizontal wispy clouds. There are 6 smaller boxes in between the two horizontal images—3 rows of 2. The first column of the boxes is outlined in orange, the second column purple and the third yellow. Each of the smaller images correspond to orange, purple, and yellow boxes placed along the horizontal images.

On the other hand, Webb’s look farther into the near-infrared than before is sensitive to the higher-altitude layers of the atmosphere, around 15-30 miles (25-50 kilometers) above Jupiter’s cloud tops. In near-infrared imaging, high-altitude hazes typically appear blurry, with enhanced brightness over the equatorial region. With Webb, finer details are resolved within the bright hazy band.

The newly discovered jet stream travels at about 320 miles per hour (515 kilometers per hour), twice the sustained winds of a Category 5 hurricane here on Earth. It is located around 25 miles (40 kilometers) above the clouds, in Jupiter’s lower stratosphere.

By comparing the winds observed by Webb at high altitudes, to the winds observed at deeper layers from Hubble, the team could measure how fast the winds change with altitude and generate wind shears.

Image: Jupiter’s Winds

A portion of the graphic that displays wind speeds on Jupiter at different altitudes. The portion of this graphic shows the ends of three arrows that travel across the graphic from the left to the right. The top most arrow (colored in sky blue) extends the farthest right to about 3/4 the way across the graphic, the middle arrow (colored in periwinkle) extends to a little less than halfway across the graphic, and the bottom arrow (colored in light grey) extends to about 1/4 the way across the graphic. Extending out below each arrow is a cone of the same color to indicate the +/- error margin. There is Webb's image of Jupiter in the background of the graphic.

Researchers using NASA’s James Webb Space Telescope’s NIRCam (Near-Infrared Camera) have discovered a high-speed jet stream sitting over Jupiter’s equator, above the main cloud decks. At a wavelength of 2.12 microns, which observes between altitudes of about 12-21 miles (20-35 kilometers) above Jupiter’s cloud tops, researchers spotted several wind shears, or areas where wind speeds change with height or with distance, which enabled them to track the jet. This image highlights several of the features around Jupiter’s equatorial zone that, between one rotation of the planet (10 hours), are very clearly disturbed by the motion of the jet stream.

: NASA, ESA, CSA, STScI, Image: NASA, ESA, CSA, STScI, R. Hueso (University of the Basque Country), I. de Pater (University of California, Berkeley), T. Fouchet (Observatory of Paris), L. Fletcher (University of Leicester), M. Wong (University of California, Berkeley), A. James (STScI)

While Webb’s exquisite resolution and wavelength coverage allowed for the detection of small cloud features used to track the jet, the complementary observations from Hubble taken one day after the Webb observations were also crucial to determine the base state of Jupiter’s equatorial atmosphere and observe the development of convective storms in Jupiter’s equator not connected to the jet.

“We knew the different wavelengths of Webb and Hubble would reveal the three-dimensional structure of storm clouds, but we were also able to use the timing of the data to see how rapidly storms develop,” added team member Michael Wong of the University of California, Berkeley, who led the associated Hubble observations.

The researchers are looking forward to additional observations of Jupiter with Webb to determine if the jet’s speed and altitude change over time.

Image: Zoom in on Webb’s View of Jupiter

A zoomed in view of Webb’s Jupiter image.

“Jupiter has a complicated but repeatable pattern of winds and temperatures in its equatorial stratosphere, high above the winds in the clouds and hazes measured at these wavelengths,” explained team member Leigh Fletcher of the University of Leicester in the United Kingdom. “If the strength of this new jet is connected to this oscillating stratospheric pattern, we might expect the jet to vary considerably over the next 2 to 4 years – it’ll be really exciting to test this theory in the years to come.”

“It’s amazing to me that, after years of tracking Jupiter’s clouds and winds from numerous observatories, we still have more to learn about Jupiter, and features like this jet can remain hidden from view until these new NIRCam images were taken in 2022,” continued Fletcher.

The researchers’ results were recently published in Nature Astronomy.

The James Webb Space Telescope is the world’s premier space science observatory. Webb is solving mysteries in our solar system, looking beyond to distant worlds around other stars, and probing the mysterious structures and origins of our universe and our place in it. Webb is an international program led by NASA with its partners, ESA (European Space Agency) and the Canadian Space Agency.