The first direct measurements of exoplanet magnetic fields reveal that ultra-hot Jupiters possess strong magnetism that shapes their atmospheres and may provide new insights into planetary habitability. Astronomers have achieved a major advance in the study of worlds beyond our Solar System by estimating the strength of the magnetic fields surrounding seven ultra-hot Jupiters. The [...]HD 80606b has one of the most extreme orbits of any known exoplanet and the NASA/ESA/CSA James Webb Space Telescope just caught it getting flash-fried as it whipped past its star.
The post Webb Sees Jupiter-Size Exoplanet Being Roasted by Its Star appeared first on Sci.News: Breaking Science News.
James Webb Space Telescope (JWST) observations have revealed the colorful secret of the Pink Planet, the coldest object of its type ever directly observed.
A team of astronomers led by Northwestern University has revealed their findings in a recent paper published in The Astronomical Journal, finally describing the rose-colored haze covering the planetary-mass companion GJ504b, thanks to JWST data.
For over a decade, researchers have speculated that atmospheric salt clouds may create the pink planet’s strange hue, but this is the first concrete evidence for the hypothesis.
Since its discovery in 2013, GJ504b, commonly known as “The Pink Planet,” has been a bit of an astronomical mystery. Even the object’s description is imprecise: a “planetary-mass companion,” a nebulous category teetering between the size of a large planet and a brown dwarf, at roughly 25 times Jupiter’s mass. Residing 57 light-years from Earth, the object’s host star is similar to our Sun.
Faint due to extremely cold temperatures, astronomers cannot obtain clear enough observations with ground-based telescopes to perform spectroscopic analysis. However, from its vantage point beyond our atmosphere, the JWST’s advanced instruments have finally provided the necessary data to make sense of the object’s strange pink atmosphere.
The exoplanets most clearly observed are much hotter than our world, with temperatures between 1,000 and 2,000°F, creating a brilliance which can be seen across the gulf of space and through Earth’s atmosphere.
This giant planet is a mere 550°F, still hot by Earth standards, but far cooler than is normal for its type. According to the new study, GJ504b is an ancient world, some 2.5 to 4billion years old, with a slow cooling over time accounting for its decreased temperature.
In addition to providing the first evidence for The Pink Planet’s elusive salt clouds, the team’s research has broader implications for studying cold objects, laying the groundwork for future JWST observations of such faint glows, too dim for ground-based telescopes.
“The Pink Planet is the coldest companion ever discovered using ground-based instruments,” according to Aneesh Baburaj, the study’s lead author. “Many teams all around the world performed follow-up observations to study its light, but it was too faint for ground-based instruments. That made it a perfect target for JWST. When we finally obtained its spectrum, it immediately looked interesting. But once we started digging deeper into the data, we realized it was not like anything we have analyzed before.”
To accurately analyze the light, Baburaj’s team used an advanced data-processing technique to remove considerable glare from the Pink Planet’s host star, improving the quality of the JWST data. Breaking light into separate colors through spectroscopic analysis allows scientists to determine the elemental composition of exoplanet atmospheres using JWST data.
“In the past, other astronomers observed the companion for an entire night with some of the biggest telescopes in the world to obtain a spectrum,” Baburaj said. “And they could not see the object. With JWST, our entire observation took around two hours, and we were successful.”
The team discovered water vapor, methane, carbon dioxide, ammonia, and other molecules in the object’s atmosphere, but these results conflicted with existing atmospheric models, which only made sense if the object had an extremely unlikely combination of physical features. However, once the team added clouds to the model, the effect of their salty formations on the light made the JWST data much easier to explain.
“We ran simulations with clouds, and the results aligned with what we know about cold planets,” Baburaj said. “We tried three different types of clouds, and salt clouds fit best. When we accounted for salt clouds, it subdued the signature of molecules hidden deeper in the companion’s atmosphere. Then, the results became physically possible.”
In addition to the salty clues, the researchers discovered an abundance of heavy metals. These may have something to do with The Pink Planet’s origins, as it may have originally formed as a star instead of a planet, but astronomers remain uncertain. In any case, the work process developed here will be essential to future JWST investigation of cold objects.
“This is the first time we’ve found that salt clouds are critical to explaining the spectrum of an object,” Baburaj concluded. “It’s a good reminder to account for clouds in our models.”
The paper, “JWST-TST High Contrast: First Direct Spectroscopy of GJ504b Reveals Clouds and Possible Metal Enrichment,” appeared in The Astronomical Journal on June 18, 2026.
Ryan Whalen covers science and technology for The Debrief. He holds an MA in History and a Master of Library and Information Science with a certificate in Data Science. He can be contacted at ryan@thedebrief.org, and follow him on Twitter @mdntwvlf.
For the first time, astronomers have distinguished between the morning and evening atmospheres of a single planet, revealing two remarkably different environments at its edges. WASP-121 b is a gas giant that orbits extremely close to its star, resulting in one hemisphere exposed to temperatures approaching 2,500 degrees Celsius while the opposite side remains in constant darkness.
A research team from the Max Planck Institute for Astronomy used the James Webb Space Telescope to provide observational evidence for a phenomenon that models had previously predicted. The boundary regions between day and night on tidally locked planets can exhibit distinct temperatures and chemical compositions.
The recent findings appeared in a study published in Nature Astronomy.
WASP-121 b is part of a group of gas giants known as hot Jupiters. These massive planets orbit their stars in just a few days and eventually become locked in place by gravity. Tidal forces keep one side facing the star at all times, while the other side never sees daylight.
“WASP-121 b is particularly extreme,” said co-author Tom Evans-Soma of the University of Newcastle, Australia. “Average temperatures on the dayside hemisphere are around 2,770 Kelvin, while those on the nightside are closer to about 1,000 Kelvin.”
The difference in temperature between the two hemispheres, which is about 1,775 degrees Celsius, makes WASP-121 b one of the most thermally extreme exoplanets known. The regions at the boundary between day and night, called terminators, are where the planet experiences constant morning or evening conditions. Scientists expected these areas to have different atmospheric properties, but only with the precision of JWST could these differences be directly observed.
The researchers used a method based on the planet’s transit across its star to study these differences. As WASP-121 b passes in front of its star, it rotates by about 30 degrees, which means that different parts of its atmosphere can be observed during each transit. By tracking how infrared starlight filters through the atmosphere over time, the team reconstructed how temperature and chemical composition change across different longitudes.
“By measuring how starlight absorption changes as WASP-121 b rotates, we probe its atmosphere longitude by longitude,” said lead author Cyril Gapp of MPIA. The observations not only confirmed what models had predicted, but also showed that the differences between the two terminators are even greater than expected.
The evening side of the planet’s terminator absorbs more starlight than the morning side. Powerful eastward winds sweep heat from the scorching dayside toward the nightside, with the evening region getting the first blast of this warmth. This extra heat causes the atmosphere there to puff up, allowing it to absorb even more starlight, as the observations showed.
Chemical measurements backed up these findings. Carbon monoxide absorption increased as the hotter regions of the evening came into view near the end of the transit. Water showed a different pattern. Rather than simply decreasing with higher temperatures, the researchers interpret the result as evidence that water molecules in the upper atmosphere are breaking apart, likely due to the intense heat at the evening terminator. This points to a real chemical change, not just a shift in molecular location.
The morning side shows a different environment. Although models predicted a difference between the two terminators, they did not fully explain why the morning side appears cooler and more opaque. The most likely explanation involves clouds that are unlike those on Earth.
At the morning terminator, air comes in from the cold nightside. Temperatures may be low enough for silicate and mineral compounds to turn into tiny particles, forming clouds that block infrared radiation from below. This makes the atmosphere appear cooler than it really is underneath.
When the team adjusted their models to account for these clouds, the results more closely aligned with their observations. Still, confirming exactly how these clouds form and behave will require more advanced modeling, as cloud formation and evaporation in such extreme environments remain a major puzzle in exoplanet science.
WASP-121 b has been the subject of previous studies, but JWST now enables astronomers to examine its atmosphere in detail, section by section. This approach is now also available for use with other exoplanets.
The team has already found other ultra-hot gas giants with the right temperatures and orbits for similar analysis. Using this method on other planets will help astronomers compare atmospheric conditions and deepen our understanding of extreme planetary environments.
Austin Burgess is a writer and researcher with a background in sales, marketing, and data analytics. He holds an MBA, a Bachelor of Science in Business Administration, and a data analytics certification. His work focuses on breaking scientific developments, with an emphasis on emerging biology, cognitive neuroscience, and archaeological discoveries.
James Webb has revealed that the sunrise and sunset sides of WASP-121 b have surprisingly different atmospheres. Astronomers using the James Webb Space Telescope (JWST) have discovered striking differences between the morning and evening sides of the atmosphere of WASP-121 b, an ultra-hot gas giant located far beyond our solar system. The findings provide the [...]The giant planet’s bow shock isn’t just deflecting the solar wind, it’s acting as a powerful particle accelerator, firing electrons to relativistic energies of at least 1 MeV, according to a new analysis of data from NASA’s Juno spacecraft.
The post Jupiter Accelerates Electrons to Near-Light Speed, Offering Clues to Cosmic Ray Origins appeared first on Sci.News: Breaking Science News.
A new Keck Observatory study indicates that giant planets can spin faster than more massive brown dwarfs, revealing important clues about how planetary systems form and evolve. Astronomers have long suspected that a planet’s mass may be linked to how quickly it spins. In our solar system, Jupiter and Saturn rotate especially fast, each completing [...]By tracking fierce winds racing through the atmospheres of seven ultra-hot Jupiters, astronomers have uncovered the strongest evidence yet that magnetic fields shape weather on worlds beyond our Solar System.
The post Astronomers Detect Clearest Signs Yet of Magnetic Fields on Extrasolar Planets appeared first on Sci.News: Breaking Science News.
Using spectral data from the Near-Infrared Spectrograph (NIRSpec) onboard the NASA/ESA/CSA James Webb Space Telescope, astronomers analyzed the atmosphere of TOI-199b, a distant Saturn-mass world that is neither frozen nor scorching hot.
The post Webb Detects Methane in Atmosphere of Exo-Saturn TOI-199b appeared first on Sci.News: Breaking Science News.
Login