Tag Archives: layers

Webb Telescope Uncovers Hidden Layers of Uranus’ Upper Atmosphere

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Astronomers have successfully mapped the vertical structure of Uranus’ ionosphere for the very first time, uncovering unexpected temperature peaks, a decline in ion density, and enigmatic dark regions influenced by the planet’s unique magnetic field. These groundbreaking findings, achieved through nearly a full day of observations using the NIRSpec instrument aboard NASA/ESA/CSA’s James Webb Space Telescope, confirm a decades-long cooling trend in Uranus’ upper atmosphere and offer an unprecedented look at how this ice giant interacts with its surrounding space differently than other celestial bodies in our solar system.

Tiranti et al. mapped the vertical structure of Uranus’s upper atmosphere, revealing variations in temperature and charged particles across different heights. Image credits: NASA / ESA / CSA / Webb / STScI / P. Tiranti / H. Melin / M. Zamani, ESA & Webb.

Uranus’s upper atmosphere remains one of the least understood components in our solar system, despite its critical role in elucidating the interactions between the giant planet and its space environment.

Astronomer Paola Tiranti from Northumbria University and her team dedicated nearly an entire day to observing Uranus with Webb’s NIRSpec instrument.

They successfully measured the vertical structure of the ionosphere, the electrically charged layer of the atmosphere where auroras occur.

“This is the first time we’ve been able to visualize Uranus’s upper atmosphere in three dimensions,” Tiranti remarked.

“Utilizing Webb’s sensitivity, we can investigate how energy migrates upward through the planet’s atmosphere, even observing the effects of polarized magnetic fields.”

Measurements revealed temperature peaks at approximately 3,000 to 4,000 km above the surface, while ion density peaked around 1,000 km, significantly weaker than previously modeled predictions.

Webb also identified two bright bands of auroral emission located near Uranus’s magnetic poles, along with an unexpected area of depleted emission and density, likely tied to the planet’s unusual magnetic field geometry.

These discoveries confirm a long-term cooling trend in Uranus’ upper atmosphere and highlight new structures shaped by its magnetic environment.

These findings offer critical benchmarks for future missions and enhance our comprehension of how giant planets—both within and beyond our solar system—maintain the energy balance in their upper atmospheres.

“Uranus’ magnetosphere is one of the most peculiar in the solar system,” Tiranti emphasized.

“Its tilt and offset from the planet’s rotational axis cause its auroras to be distributed in a complex fashion across the surface.”

“Webb has provided insights into how deeply these effects penetrate into the atmosphere.”

“By detailing Uranus’s vertical structure so thoroughly, Webb aids in our understanding of the energy balance of the ice giant.”

“This represents a significant step toward characterizing giant planets beyond our solar system.”

For further details, refer to the results published in the journal Geophysical Research Letters.

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Paola I. Tiranti et al. 2026. JWST uncovers the vertical structure of Uranus’ ionosphere. Geophysical Research Letters 53 (4): e2025GL119304; doi: 10.1029/2025GL119304

Source: www.sci.news

Planetary Scientists Discover Seasonal Ozone Layers Formed by Mars’s Arctic Vortex

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Polar water is generated during the Martian season, which occurs due to the planet’s axis being tilted at an angle of 25.2 degrees, as explained by Dr. Kevin Olsen from Oxford and his colleagues at Latmos, CNRS, CNRS, Space Research Institute, Open University, and NASA.

This perspective view of Mars’ Arctic Ice Cap showcases its unique dark troughs arranged in a spiral pattern. The image is derived from observations made by ESA’s Mars Express, utilizing elevation data from NASA’s Mars Global Surveyor’s Mars Orbiter Laser Altimeter. Image credit: ESA/DLR/FU Berlin/NASA/MGS/MOLA Science team.

“The polar vortex’s atmosphere, extending from near the surface to around 30 km high, experiences extremely low temperatures, approximately 40 degrees Celsius lower than the surrounding area,” stated Dr. Olsen.

“In such frigid conditions, most of the water vapor in the atmosphere freezes and accumulates in the ice cap, resulting in ozone formation within the vortex.”

Normally, ozone is destroyed by reacting with molecules generated when ultraviolet radiation decomposes water vapor.

However, once all water vapor is depleted, there are no reactive molecules left for ozone, allowing it to accumulate in the vortex.

“Ozone plays a crucial role for Mars. It is a reactive form of oxygen that indicates the pace of chemical reactions occurring in the atmosphere,” Olsen noted.

“By investigating the levels of ozone and their variances, we gain insight into how the atmosphere evolves over time and whether Mars once had a protective ozone layer similar to Earth.”

Slated for launch in 2028, ESA’s Rosalind Franklin Rover aims to uncover evidence of life that may have existed on Mars.

The possibility that Mars had a protective ozone layer, safeguarding its surface against harmful ultraviolet radiation from space, enhances the likelihood of ancient life-sustaining conditions on the planet billions of years ago.

Polar vortices are produced during the Martian season as a consequence of the axial tilt of 25.2 degrees.

Similar to Earth, an atmospheric vortex forms above Mars’ North Pole at the end of summer and persists through spring.

On Earth, polar vortices can destabilize, losing their structure and shifting southward, often bringing cold weather to mid-latitudes.

A similar phenomenon can occur with Mars’ polar water vortex, which provides an opportunity to explore its internal dynamics.

“Studying the Northern Pole’s winter on Mars presents challenges due to the absence of sunlight, akin to conditions on Earth,” Dr. Olsen explained.

“By analyzing the vortex, one can differentiate between observations made inside and outside it, providing insight into ongoing phenomena.”

The atmospheric chemical suite aboard ESA’s trace gas orbiter examines Mars’ atmosphere by capturing sunlight filtered through the planet’s limb while the sun is positioned behind it.

The specific wavelengths of absorbed sunlight reveal which molecules are present in the atmosphere and their altitudes above the surface.

Nonetheless, this method is ineffective during the complete winter darkness on Mars when the sun does not illuminate the Arctic region.

The only chance to observe the vortex is during moments when its circular shape is lost, but additional data is required to pinpoint when and where this occurs.

To enhance their research, the scientists utilized NASA’s Mars Reconnaissance Orbiter’s Mars Climate Sounder instrument, measuring temperature variations to gauge the vortex’s extent.

“We sought sudden drops in temperature, which indicate entry into the vortex,” Dr. Olsen noted.

“By comparing ACS observations with data from Mars’ climate sounders, we observed significant atmospheric differences within the vortex compared to the surrounding air.”

“This presents a fascinating opportunity to deepen our understanding of Mars’ atmospheric chemistry and how polar night conditions shift as ozone accumulates.”

The findings were presented at the EPSC-DPS2025 Joint Meeting in Helsinki, Finland, this month.

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K. Olsen et al. 2025. What’s happening in the Arctic Vortex of Mars? EPSC Abstract 18: EPSC-DPS2025-1438; doi: 10.5194/epsc-dps2025-1438

Source: www.sci.news

Research on the various cloud layers, temperature hot spots, and shifting chemistry found in the extraterrestrial realm

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New observations from the NASA/ESA/CSA James Webb Space Telescope support the presence of three specific functions in the atmosphere (clouds, hot spots, and changes in carbon chemistry) of the rapidly rotating and free floating planetary mass object SIMP J013656.5+093347.

Impressions of the artist of SIMP 0136. Image credits: NASA/ESA/CSA/J. Olmsted, Stsci.

SIMP J013656.5+093347 (SIMP 0136 for short) is a rapidly rotating, free-floating object located just 20 light years from Earth.

It may have a mass of 13 Jupiter masses, does not orbit the star, and instead may be a brown dwarf.

Because it is separated, SIMP 0136 can be directly observed and is not afraid of mild contamination or variability caused by the host star.

The short rotation period, only 2.4 hours, allows for very efficient investigation.

“We've been working hard to get into the world,” said Allison McCarthy, a doctoral student at Boston University.

“We also thought that it might have an effect on temperature fluctuations, chemical reactions, and perhaps the activity of the aurora affecting brightness, but we weren't sure.”

Webb's NirSpec Instruments We captured thousands to 5.3 micron spectra of SIMP 0136. The object completed one full rotation, so I captured it one at a time, one at a time, one at a time, one at a time, over 3 hours.

This led to immediate observation Webb's Milli Musical Instrumentshundreds of measurements of light between 5 and 14 microns were collected. One is one every 19.2 seconds, one in another rotation.

The results were hundreds of detailed rays, each showing a very accurate wavelength (color) brightness change, with different sides of the object rotating into view.

“It was incredible to see the entire range of this object change over a few minutes,” said Dr. Joanna Foss, an astronomer at Trinity College Dublin.

“Until now, we only had a small near-infrared spectrum from Hubble, but we had some brightness measurements from Spitzer.”

Astronomers almost immediately noticed that there were several distinct ray shapes.

At any time, some wavelengths were growing brightly, while others were either dimmed or not changing at all.

Many different factors must affect brightness variation.

“Imagine looking at the Earth from afar,” said Dr. Philip Muirhead, a former member of Boston University.

“Looking each color individually gives you a variety of patterns that tell you something about the surface and the atmosphere, even if you don't understand the individual features.”

“As the ocean rotates towards vision, blue increases. The brown and green changes tell us something about the soil and vegetation.”

To understand what could cause variability in SIMP 0136, the team used an atmospheric model to show where each wavelength of light is occurring in the atmosphere.

“The different wavelengths provide information about the different depths in the atmosphere,” McCarthy said.

“We began to realize that the wavelengths that had the most similar ray shapes also investigated the same depth and reinforced this idea that they must be caused by the same mechanism.”

For example, one group of wavelengths occurs deeply in the atmosphere where there may be patchy clouds made of iron particles.

The second group comes from high clouds, which are thought to be made from small grains of silicate minerals.

Both of these light curve variations are related to the patchiness of the cloud layers.

The third group of wavelengths appears to be occurring at very high altitudes far above the clouds and tracking temperatures.

Bright hotspots may be associated with previously detected auroras at radio wavelengths, or hot gas upwelling from deeper in the atmosphere.

Some light curves cannot be explained by clouds or temperature, but instead show variations related to atmospheric carbon chemistry.

There may be chemical reactions in which carbon monoxide and carbon dioxide pockets rotate within and outside of view, or alter the atmosphere.

“We still don't understand the chemical part of the puzzle yet,” Dr. Vos said.

“But these results are really exciting because they show that the richness of molecules like methane and carbon dioxide can change over time from location.”

“If you're looking at a deplanet and only have one measurement, you should assume that it may not be representative of the entire planet.”

Survey results It will be displayed in Astrophysics Journal Letter.

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Allison M. McCarthy et al. 2025. JWST weather report from isolated exoplanet analog SIMP 0136+0933: pressure-dependent variability driven by multiple mechanisms. apjl 981, L22; doi: 10.3847/2041-8213/AD9EAF

Source: www.sci.news