NIRSpec Archives

Tracing The Source Of Carbon Oxides On The Large Moons Of Uranus

by Keith CowingJuly 18, 2026July 18, 2026

[astro-ph.EP] The Uranian moons Ariel, Umbriel, Titania, and Oberon are enriched in CO2 mixed with CO, but the origin(s) of these carbon oxides, be they primarily native or radiolytic, remains […]

β Pic d possible orbits and stability fractions. Left: Allowed orbits (pink) from Octofitter (W. Thompson et al. 2023) posteriors fit to astrometry and planetary RV (black) reported in Table 1, projected on-sky. Possible orbits are also shown in RV space. The locations of β Pic b and the approximate inner edge of the debris disk are plotted for reference. β Pic c is not shown as it falls nearly coincident with the star. Right: Fraction of stable orbits as a function of β Pic d mass and semi-major axis, as determined by the MEGNO chaos indicator from orbit posteriors integrated over 5 Myr. The semi-major axis range of the 68% percentile orbit posteriors is overlaid in pink. Orbital period ratios with β Pic b are shown as white dashed lines. The pink shaded region represents the 68th percentile of the orbital posteriors. The current astrometric baseline and RV precision do not strongly constrain the orbit; however, stability requirements suggest a semi-major axis of > 30 au. -- astro-ph.EP

Beta Pictoris

Discovery Of An Exterior Third Planet Orbiting β Pictoris

by Keith CowingJuly 2, 2026July 2, 2026

[astro-ph.EP] We report the discovery of β Pictoris d (β Pic d), a third giant planet in the β Pictoris system, which now becomes only the second directly imaged system […]

Transmission spectra of TOI-6894 b from two independent reductions

Exoplanets, -moons, -comets

C,N,O,S, And Photochemistry In A Temperate Giant Planet Orbiting A Late M Dwarf

by Keith CowingJuly 2, 2026July 2, 2026

[astro-ph.EP] We report the JWST NIRSpec/PRISM transit spectrum of TOI-6894b, an exceptional 420 K sub-Saturn that is the only known giant planet transiting a late M dwarf. Remarkably, both the […]

Interstellar Comet 3I/ATLAS (NIRSpec IFU) -- ESA (larger Image)

Comets and Asteroids

Webb Finds Clues To The Ancient Origin Of Comet 3I/ATLAS

by Keith CowingJune 23, 2026June 23, 2026

The third identified interstellar comet in human history has a surprising chemical makeup, raising questions as to how common, or unusual, conditions in our own Solar System may be.

For each shaded region (i.e., species) in the top figure, the plots on the left show the spectral signature of the specific molecule (in color) superposed on the residuals (in black) between the planet spectrum and the best-fit reduced model (model without species of interest), while the right plots show the detection signal-to-noise using the cross-correlation technique. -- astro-ph.EP

Astronomy & Telescopes, Atmospheres, Climate, Weather, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report

JWST-TST High Contrast: First Direct Spectroscopy of GJ 504 b Reveals Clouds And Possible Metal Enrichment

by Keith CowingJune 20, 2026June 20, 2026

Characterizing the coldest directly imaged companions through direct spectroscopy has only recently become possible with the James Webb Space Telescope.

NIRSpec average spectrum of Titan (black) compared with a radiative transfer calculation in which the surface albedo decreases smoothly with wavelength beyond 4.9 µm (red). The blue line shows the difference between the observed and synthetic spectra, shifted by 0.005 for clarity. The 5.11-µm absorption is clearly missing in the model. The small mismatch below 4.93 µm is due to a component of the non-LTE CO emission not included in the model. -- astro-ph.EP

Astrochemistry, Astronomy & Telescopes, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Icy Worlds, Imaging & Spectroscopy, Pluto, Status Report, Titan

An Unidentified Absorption Feature At 5.11 μm On The Surface Of Titan And Pluto From JWST Spectroscopy

by Keith CowingJune 12, 2026June 12, 2026

Titan possesses a thick N2-CH4 atmosphere that makes it difficult to study its surface spectroscopically. The chemical composition of the solid surface of Titan thus remains very uncertain.

NGTS-10 b is a gas giant exoplanet that orbits a K-type star. Its mass is 2.162 Jupiters, it takes 0.8 days to complete one orbit of its star, and is 0.0143 AU from its star. Its discovery was announced in 2020. -- Grok via Astrobiology.com - inspired by NASA source

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

Horizontal Transport As A Source Of Disequilibrium Chemistry On The Nightside Of A Hot Exoplanet

by Keith CowingMay 2, 2026May 2, 2026

Hot Jupiters have temperature gradients of several hundreds of degrees between their permanent daysides and nightsides. Such a strong gradient creates winds with speeds of the order of kilometres per […]

Predicted relative transit depth change from the equilibrium chemistry CO2-only model retrieved for CRIRES+ data (green). The model predictions are plotted in high-resolution in the wavelength region overlapping with the CRIRES+ measurements indicated by the grey shaded areas and in low-resolution for the rest of the wavelength range. Space-based measurements from HST (blue) and JWST (orange) are also shown. The 1σ and 1.5σ uncertainties of the model are indicated as darker and lighter green shaded areas, respectively. We also mark the lower 1.1σ uncertainty boundary with a dotted green line as a potential match to the amplitude of the CO2 bump in the JWST measurements at 4200 nm. The HST-WFC3 and JWST NIRSpec G359H measurements were taken from the online data provided by Schlawin et al. (2024) containing the HST data adapted from Kreidberg et al. (2014).-- astro-ph.EP

Astrochemistry, Astronomy & Telescopes, Atmospheres, Climate, Weather, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report

Cloudy With A Chance Of Metals: Indications Of CO2 In The Atmosphere Of GJ 1214 b From High-resolution K-band Spectroscopy

by Keith CowingApril 19, 2026April 19, 2026

Sub-Neptune exoplanets frequently exhibit muted transmission spectra, with GJ 1214 b being the most prominent example. Following years of intense observing campaigns yielding featureless planetary spectra, recent observations with JWST […]

Pressure–temperature (P–T) conditions of our experiments compared to phase diagram of the CO2–H2O system. Red dots correspond to actual P–T conditions at various stages of ice preparation. Dashed lines are only indicative and do not correspond to measured variations in pressure. Paths labeled in red, yellow, and magenta correspond to ice retaining CO2. Paths labeled in black correspond to ice devoid of CO2. Lowercase letters show the stages of the experiment described in the text, with subscripts showing the applicable experiment number. The stars near the bottom left denote the P–T conditions during acquisition of spectra. -- astro-ph.EP

Astrochemistry, Astrogeology, Atmospheres, Climate, Weather, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biophysics, Biosignatures & Paleobiology, Europa, Icy Worlds, Imaging & Spectroscopy, Status Report

The Fate Of Frozen Carbonated Water At Europa-like Conditions

by Keith CowingApril 13, 2026April 13, 2026

We present the results of experiments probing the retention of CO2 in crystalline water ice, frozen sodium chloride (NaCl) brines, and flash-frozen carbonated water using diffuse reflectance infrared spectroscopy.

Visualization of the HAT-P-12b transmission spectrum and the underlying opacity contributions. Top: Combined spectra from the three JWST instruments and HST STIS (Alexoudi et al. 2020) with 1σ uncertainties, together with the best-fit model with its 3σ credible interval.Model spectra including only the opacity of individual contributors (chemical species or non-gray cloud parametrization) are also shown. Bottom: Absorption cross sections σ of all tested chemical species; significantly detected species are emphasized with thicker lines. -- astro-ph.EP

Astronomy & Telescopes, Atmospheres, Climate, Weather, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report

Information Content Of JWST Transmission Spectroscopy Of The Exoplanet HAT-P-12b From The Optical To The Mid-infrared

by Keith CowingApril 4, 2026April 4, 2026

Marginal posterior distributions of the chemical abundances for all included molecules, retrieved using different JWST instrument combinations. The shown distributions were derived from the samples via kernel density estimation (KDE; […]

NIRSpec

Tracing The Source Of Carbon Oxides On The Large Moons Of Uranus

Discovery Of An Exterior Third Planet Orbiting β Pictoris

C,N,O,S, And Photochemistry In A Temperate Giant Planet Orbiting A Late M Dwarf

Webb Finds Clues To The Ancient Origin Of Comet 3I/ATLAS

JWST-TST High Contrast: First Direct Spectroscopy of GJ 504 b Reveals Clouds And Possible Metal Enrichment

An Unidentified Absorption Feature At 5.11 μm On The Surface Of Titan And Pluto From JWST Spectroscopy

Horizontal Transport As A Source Of Disequilibrium Chemistry On The Nightside Of A Hot Exoplanet

Cloudy With A Chance Of Metals: Indications Of CO2 In The Atmosphere Of GJ 1214 b From High-resolution K-band Spectroscopy

The Fate Of Frozen Carbonated Water At Europa-like Conditions

Information Content Of JWST Transmission Spectroscopy Of The Exoplanet HAT-P-12b From The Optical To The Mid-infrared

Planetesimal Formation Across the Stellar Mass Spectrum and its Influence on Exoplanet-Inherited Volatile Budgets

Astronaut Training For Underground Science Expeditions

Achieving Efficient Broadband Spatial Filtering For LIFE: Status And Plan

A Comprehensive Study Of Comet 67P/Churyumov-Gerasimenko In The 2021/2022 Apparition. II. Colorimetry, Polarimetry, Modeling

Mars Express And Psyche Same Day Imagery of Mars