gas giant Archives

Artistic representation of WASP-94 A b. Clouds build as air flows over the dark side of the planet, reaching a large swell by daybreak. The clouds dissipate on the dayside, leaving clear skies in the early evening. Image courtesy of Hannah Robbins/Johns Hopkins University

Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Gas Giants, Imaging & Spectroscopy, Status Report, Water/Hycean Worlds & Oceanography

Astronomers Observe Exoplanet Atmospheres With New Cloud-detecting Method

by Keith CowingMay 22, 2026May 22, 2026

Every morning, clouds roll in, and by evening, they have cleared off. This sounds like a weather forecast for a coastal city here on Earth — but it’s for WASP-94A […]

Artist's impression of a gas giant planet orbiting its distant host star. New research, led by astronomers at Penn State and the Jet Propulsion Laboratory, used NASA’s James Webb Space Telescope to analyze the atmosphere of a gas giant planet about the size of Saturn but with Earth-like temperatures and found it to be rich in methane. Credit: NASA/JPL-Caltech.

Astronomy & Telescopes, Atmospheres, Climate, Weather, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Gas Giants, Habitable Zones, Imaging & Spectroscopy, Press Release

Atmosphere Of Saturn-sized Planet With Earth-like Temperature Contains Methane

by Keith CowingMay 21, 2026May 21, 2026

A planet that is about the size of Saturn, but with a temperature more like Earth’s, has an atmosphere rich in methane, according to a new study using NASA’s James […]

Two orders of high-resolution spectra with the best-fit model overplotted in yellow for each target. The observation on the first day (September 21, 2022) is chosen for 2MASS J0249-0557 c. The wavelength range is selected to include the 12CO and 13CO bandheads. -- astro-ph.EP

Astronomy & Telescopes, Atmospheres, Climate, Weather, Beta Pictoris, Brown Dwarfs, Exoplanets, -moons, -comets, Gas Giants, Status Report

Chemistry And Isotope Ratios Of Substellar Atmospheres In The β Pictoris Young Moving Group

by Keith CowingMay 6, 2026May 6, 2026

Measuring the chemical and isotopic compositions of gas giants and brown dwarfs provides insights into their formation pathways and birth environments. 2MASS J0249-0557 c is an L2-type planetary mass companion […]

Thermal evolution of a 1 M⊕ model with no atmosphere (top row) and a model with a thin 0.01% H-He by mass atmosphere/envelope.

Astrochemistry, Astrogeology, Desert Worlds, Exoplanets, -moons, -comets, Gas Giants, Ice Giant, Icy Worlds, Status Report, Water/Hycean Worlds & Oceanography

ORCHARD: A General Planetary Evolution Code

by Keith CowingApril 30, 2026April 30, 2026

We present ORCHARD, a publicly available planetary evolution code based on the gas giant evolution code, APPLE, capable of modeling the evolution and structures of terrestrial, super-Earth, sub-Neptune, Neptune, and […]

Observation and cube detector images of channel 1A to 4A, where channel 4A gets neglected from further analysis (see text). The red cross corresponds to the position of the target and the blue circle to the aperture from which the flux has been extracted from. The two negative spots on the detector correspond to two nods originating from the background subtraction. The yellow circle shows the position of a background object. -- astro-ph.EP

Astrochemistry, Astrogeology, Astronomy & Telescopes, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Gas Giants, Icy Worlds, Imaging & Spectroscopy, Status Report

Oxygen And Nitrogen Isotopologues On Cold COCONUTS-2b Observed With MIRI/MRS

by Keith CowingApril 30, 2026April 30, 2026

Linking the composition of gas giant planets to their formation paths has long been a goal in exoplanet science. Especially, cold gas giants with temperatures below ∼500K have been out […]

WASP-39b transmission spectra and cloud scenarios. Spectra are observed with JWST (orange), HST (magenta), and VLT (green) in comparison to models with different Fe content: full IWF Graz cloud model (black line), Fe[s] replaced (dark gray), FeS[s] replaced (middle gray), and all Fe-binding materials replaced (light gray). The Fe-free mixed-material cloud compositions provide a good fit in the near-IR but not in the optical. — astro-ph.EP

Exoplanets, -moons, -comets, Gas Giants, Status Report

Exoplanet Climate Characterization With Transit Asymmetries

by Keith CowingApril 28, 2026April 28, 2026

Context. Space missions such as CHEOPS, JWST, and PLATO facilitate detailed characterization of exoplanets, particularly close-in gas giants and their wide range of global temperatures and climate regimes.

The retrieved transmission spectrum using the results from the free retrieval plotted as a black line, along with the transmission data from NIRCam F322W2, F444W, and MIRI LRS plotted as black dots with 1 sigma error bars. Contributing absorption is plotted in various colors to show where gas species contribute the transmission spectrum. From the gas contributions we can see by eye that the absorption of CS2 matches the features at 4.6 µm and 6.5 µm nicely. --astro-ph.EP

Astrochemistry, Atmospheres, Climate, Weather, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Gas Giants, Imaging & Spectroscopy, Status Report

The Identification of CS2 and Evidence for Carbon-Sulfur Chemical Coupling in a Warm Giant Exoplanet Atmosphere

by Keith CowingApril 17, 2026April 17, 2026

Transmission spectroscopy with the James Webb Space Telescope (JWST) is revealing growing chemical complexity in giant exoplanet atmospheres. Of particular interest is sulfur, which had essentially no observational constraints before […]

Exoplanet 29 Cygni b, seen in this artist’s concept, is a gas giant weighing about 15 times the mass of Jupiter. It orbits a type A star (shown at upper right) slightly hotter and more massive than our Sun, at an average distance of 2.4 billion kilometres.-- Credit: NASA, ESA, CSA, J. Olmsted (STScI)

Astrogeology, Astronomy & Telescopes, Exoplanets, -moons, -comets, Gas Giants, Status Report, Stellar Cartography

Webb Redefines The Dividing Line Between Planets And Stars

by Keith CowingApril 14, 2026April 14, 2026

Planets, like those in our Solar System, form in a bottom-up process where small bits of rock and ice clump together and grow larger over time. But the heftier the […]

The transit fitting results for KOI-1300.01. The upper right panel shows the phase-folded and contamination-corrected transit lightcurve for the planet’s circumprimary case. The gray circles are the normalized and contamination corrected flux values. The blue squares are the normalized flux values obtained from binning 800 data points at a time. The red line is the model fit to the data. The lower right panel shows the same information for the circumsecondary case. The upper left panels shows the corner plots from the MCMC sampling in the circumprimary case. The lower left shows the corner plots for the circumsecondary case. -- astro-ph.EP

Astronomy & Telescopes, Exoplanets, -moons, -comets, Status Report, Stellar Cartography

Determining the Host Stars of Planets in Binary Star Systems with Asterodensity Profiling: Investigating the Canonical Radius Gap

by Keith CowingApril 9, 2026April 9, 2026

Over the past 30 years, thousands of exoplanets have been discovered, revealing detailed demographics of planets outside the Solar System.

Artist’s impression of the simulations conducted in this research. Jupiter (lower left) has a strong magnetic field which creates a cavity in its circumplanetary disk. Saturn (upper right) lacks a strong magnetic field so its circumplanetary disk evolves without a cavity. Credit: Yuri I. Fujii/L-INSIGHT [Kyoto University], Illustrator: Shinichiro Kinoshita

Astrogeology, Callisto, Enceladus, Europa, Ganymede, Gas Giants, Icy Worlds, Io, Jupiter, Magnetic Fields, Electromagnetism, bioelectricity,, Press Release, Rhea, Saturn, Titan, Water/Hycean Worlds & Oceanography

How Jupiter Cultivated More Large Moons Than Saturn

by Keith CowingApril 8, 2026April 8, 2026

The two largest planets in our Solar System, Jupiter and Saturn, also have the largest satellite systems, or the most moons. At present, Jupiter’s reported moon count stands at more […]