Jupiter in ultraviolet light

The NASA Hubble Space Telescope has captured a striking image of Jupiter in a color composite of ultraviolet wavelengths. Released on November 3, 2023, to commemorate Jupiter reaching opposition—when the planet and the Sun are on opposite sides of the sky—the image highlights the gas giant’s iconic features, including the massive storm known as the “Great Red Spot.”

Image credit: NASA, ESA, and M. Wong (University of California – Berkeley); Processing: Gladys Kober (NASA/Catholic University of America)

In this ultraviolet image, the storm appears darker than it does to the human eye, as high-altitude haze particles absorb light at these wavelengths. In contrast, the reddish, wavy polar hazes absorb slightly less ultraviolet light due to differences in particle size, composition, or altitude. This view provides valuable data for understanding Jupiter’s atmospheric dynamics and contributes to the broader knowledge of planetary systems.

Behind the photo: Hubble captures Jupiter in ultraviolet light

This image from the NASA Hubble Space Telescope shows the planet Jupiter in a color composite of ultraviolet wavelengths. Released in honor of Jupiter reaching opposition, which occurs when the planet and the Sun are in opposite sides of the sky, this view of the gas giant planet includes the iconic, massive storm called the “Great Red Spot.” Though the storm appears red to the human eye, in this ultraviolet image, it appears darker because high-altitude haze particles absorb light at these wavelengths. The reddish, wavy polar hazes absorb slightly less of this light due to differences in particle size, composition, or altitude. 

The data used to create this ultraviolet image is part of a Hubble proposal that looked at Jupiter’s stealthy superstorm system. The researchers plan to map deep water clouds using the Hubble data to define 3D cloud structures in Jupiter’s atmosphere.

Hubble has a long history of observing the outer planets. From the Comet Shoemaker-Levy 9 impacts to studying Jupiter’s storms, Hubble’s decades-long career and unique vantage point provide astronomers with valuable data to chart the evolution of this dynamic planet.

Hubble’s ultraviolet-observing capabilities allow astronomers to study the short, high-energy wavelengths of light beyond what the human eye can see. Ultraviolet light reveals fascinating cosmic phenomena, including light from the hottest and youngest stars embedded in local galaxies; the composition, densities, and temperatures of the material between stars; and the evolution of galaxies.

This is a false-color image because the human eye cannot detect ultraviolet light. Therefore, colors in the visible light spectrum were assigned to the images, each taken with a different ultraviolet filter. In this case, the assigned colors for each filter are: Blue: F225W, Green: F275W, and Red: F343N.

Jupiter in Blue, Ultraviolet and Near Infrared

Image credit: NASA/JPL/University of Arizona

Three images of Jupiter, taken through the narrow-angle camera of NASA’s Cassini spacecraft from a distance of 77.6 million kilometers (48.2 million miles) on October 8, reveal more than is apparent to the naked eye through a telescope.

The image on the left was captured through the blue filter, the one in the middle through the ultraviolet, and the one on the right in the near infrared.

The blue-light filter lies within the part of the electromagnetic spectrum detectable by the human eye. As a result, Jupiter’s appearance in this image is very familiar. The Great Red Spot, located below and to the right of center, and the planet’s well-known banded cloud lanes are clearly visible. The brighter bands of clouds, known as zones, are likely composed of ammonia ice particles, while the darker bands, called belts, are darkened by particles of unknown composition intermixed with the ammonia ice.

Jupiter’s appearance changes dramatically in the ultraviolet and near-infrared images. These images are near negatives of each other and demonstrate how observations in different wavelength regions can reveal varying physical regimes on the planet.

All gases scatter sunlight efficiently at short wavelengths, a phenomenon that makes Earth’s sky appear blue. This effect is even more pronounced in the ultraviolet. The gases in Jupiter’s atmosphere above the clouds scatter ultraviolet light strongly, making the deep banded cloud layers invisible in the ultraviolet image. Only the very high-altitude haze appears dark against the bright ultraviolet background.

In the near-infrared image, the contrast is reversed. Methane gas, which is abundant on Jupiter but not on Earth, absorbs near-infrared light strongly, appearing dark. The deep clouds remain invisible, but high-altitude hazes stand out brightly against the darker background. These high-altitude hazes are particularly noticeable over the poles and equator.

The Great Red Spot, a prominent feature in all three images, demonstrates its significant influence at high altitudes in Jupiter’s atmosphere. With Cassini’s continued imaging of Jupiter, scientists will be able to construct a three-dimensional understanding of how the planet’s clouds form and evolve by observing its changing appearance across different spectral regions.

The Jet Propulsion Laboratory (JPL) manages the Cassini mission for NASA’s Office of Space Science in Washington, D.C. JPL is a division of the California Institute of Technology in Pasadena.

Why ultraviolet imaging is important for studying Jupiter

Observing Jupiter in ultraviolet light allows scientists to study the upper layers of the planet's atmosphere, including its interactions with solar radiation. The data reveals unique insights into atmospheric composition, energy transfer, and the behavior of charged particles near the planet's poles.

Jupiter’s opposition

Jupiter's opposition occurs approximately every 13 months, marking the point when the planet is closest to Earth in its orbit. This alignment not only makes Jupiter appear brighter and larger in the night sky but also provides astronomers with optimal conditions for observation.

The history and significance of the Great Red Spot

The Great Red Spot, a massive storm larger than Earth, has been a prominent feature of Jupiter for centuries. Ultraviolet observations provide clues about its longevity, structure, and evolving size, which has been shrinking over recent decades.

Comparisons between Jupiter and other planets in our solar system

By studying Jupiter, astronomers can draw parallels to other gas giants like Saturn, Uranus, and Neptune. These comparisons enhance our understanding of planetary atmospheres and weather systems on a larger scale.

Statements from scientists involved in the research

“Ultraviolet imaging offers a fresh perspective on Jupiter’s atmospheric dynamics,” said Dr. Michael Wong from the University of California, Berkeley. “Each observation helps us piece together the puzzle of this fascinating planet.”

The impact of the release on public interest in space

NASA’s continued efforts to share stunning images from Hubble inspire curiosity and promote science education. These images not only showcase the beauty of our solar system but also highlight the importance of ongoing space exploration.

The role of the Hubble Space Telescope in advancing planetary science:

Since its launch in 1990, Hubble has revolutionized our understanding of the cosmos. Its ability to observe in ultraviolet wavelengths remains a testament to its enduring value in modern astronomy.

View the full press release