MIRI Archives

NASA’s Webb imaged a possible planet with a mass similar to Saturn orbiting the star TWA 7. Light from the star has been subtracted from this image to reveal the candidate planet, shown in data from Webb’s MIRI (orange, upper right). The star’s location is indicated with a circle with a star symbol. Its debris disk (blue) was imaged by ESO’s Very Large Telescope. Credit: NASA, ESA, CSA, Anne-Marie Lagrange (CNRS, UGA), Mahdi Zamani (ESA/Webb)

Astronomy & Telescopes, Exoplanets, -moons, -comets, Gas Giants, Imaging & Spectroscopy, Press Release

A Saturn-Mass Planet Imaged by Webb Is The Lightest Ever Seen

by Keith CowingJune 25, 2025June 25, 2025

The James Web Space Telescope’s MIRI instrument, managed by NASA JPL through launch, detected a compact object in the disk of debris surrounding a nearby star.

F1550C image of α Cen AB. α Cen B is saturated near the top and α Cen A is behind the F1550C mask near the center. Two known background stars are labeled (KS2 inset, detected after PSF subtraction; and KS5). The (right) colorbar (for the Stage 2b image) is logarithmically scaled in MJy/sr. A ≈ 35 radius region around α Cen A is expanded. (a) The original α Cen AB PSF-subtracted image. Dashed lines indicate the FQPM boundaries. A likely artifact is boxed. (b) An identical reduction after injecting STPSF planet models (circled). (c) An identical reduction after injecting an exozodiacal disk model (boxed). The (bottom) colorbar (for the reduced images and KS2) is linearly scaled in MJy/sr. -- Research Notes of the AAS

Alpha Centauri, Astronomy & Telescopes, Exploration Gear & Tech, Imaging & Spectroscopy, Press Release

A Preliminary Search For Planets and Exozodiacal Emission Around Alpha Centauri A with JWST/MIRI

by Keith CowingMay 26, 2025May 26, 2025

We present F1550C (15.5 μm) coronagraphic imaging observations of the nearest solar-type star α Cen A using the James Webb Space Telescope (JWST) Mid-InfraRed Instrument (MIRI).

A modern Earth thermodynamic calculation using the Gibbs free energy thermodynamics model. Each species included in the calculation is listed along the bottom with their respective mixing ratios on the y-axis. The blue bars represent the observed abundances for each species and the red bars indicate the equilibrium abundance of each species. The yellow bars show the fractional difference in between the observed and equilibrium abundances, normalized by the observed values. The “(-)” annotations indicate a decrease in mixing ratio takes place in order to reach equilibrium. This calculation was done at a pressure of 1 bar and a temperature of 288 K. -- astro-ph.EP

Astrochemistry, Astronomy & Telescopes, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Imaging & Spectroscopy, SETI & Technosignatures, Status Report

Modern Earth-like Chemical Disequilibrium Biosignatures Are Challenging To Constrain Through Spectroscopic Retrievals

by Keith CowingMay 23, 2025May 23, 2025

Robust exoplanet characterization studies are underway, and the community is looking ahead toward developing observational strategies to search for life beyond our solar system.

Wolf 359 images from NIRCam (blue) and MIRI (red) before and after PSF subtraction. PSF subtraction was performed in order to improve the sensitivity to finding faint astrophysical sources near the star. The white circle represents an angular separation of 15 AU for the Wolf 359 system. The dark spots in the background of the PSF subtracted frames are due to positive sources in the reference star frames; this issue is expected to be mitigated in future analysis when additional reference stars are available. In the MIRI F2100W frames, an image artifact is present approximately 75 pixels above the center of the star. Future proper motion followup observations are needed to identify if uncataloged point sources are co-moving companions. -- astro-ph.EP

Astronomy & Telescopes, Exoplanets, -moons, -comets, Gas Giants, Imaging & Spectroscopy, Jupiter, Saturn, Status Report

JWST MIRI Imaging Can Directly Detect Exoplanets Of The Same Temperature, Mass, Age, And Orbital Separation As Saturn And Jupiter

by Keith CowingMay 23, 2025May 23, 2025

NIRCam and MIRI coronagraphy have successfully demonstrated the ability to directly image young sub-Jupiter mass and mature gas-giant exoplanets.

The retrieved spectra using the hybrid equilibrium chemistry model and machine learning approaches are shown. Observations from JWST instruments are illustrated with different colored error bars: green for NIRISS, blue for NIRSpec PRISM, and golden for MIRI. -- astro-ph.EP

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

A Next-Generation Exoplanet Atmospheric Retrieval Framework for Transmission Spectroscopy (NEXOTRANS): Comparative Characterization for WASP-39 b Using JWST NIRISS, NIRSpec PRISM, and MIRI Observations

by Keith CowingMay 2, 2025May 2, 2025

The advent of JWST has marked a new era in exoplanetary atmospheric studies, offering higher-resolution data and greater precision across a broader spectral range than previous space-based telescopes.

Astrochemistry, Astrogeology, Astronomy & Telescopes, Atmospheres, Climate, Weather, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, Press Release

Strongest Hints Yet Of Biological Activity Outside Our Solar System

by Keith CowingApril 17, 2025April 17, 2025

Astronomers have detected the most promising signs yet of a possible biosignature outside the solar system, although they remain cautious. Using data from the James Webb Space Telescope (JWST), the […]

The mid-infrared transmission spectrum of K2-18 b obtained with the JWST MIRI LRS instrument. The data points with error bars (in brown) show the observed spectrum as described in section 2.1. The horizontal errorbars correspond to the spectral bin width. The dark blue curve denotes the median retrieved spectral fit, while the two lighter shaded regions denote the 1- and 2-σ intervals. The prominent features of DMDS and DMS are identified. Both molecules have overlapping spectral features between 6.8-8 µm, with broader features between ∼9-10 µm for DMS and ∼10-11 µm for DMDS. The individual spectral contributions of these molecules are shown in Figure 3. -- astro-ph.EP

Astrochemistry, Astronomy & Telescopes, Atmospheres, Climate, Weather, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report, Water/Hycean Worlds & Oceanography

New Constraints On DMS and DMDS In The Atmosphere Of K2-18 b From JWST MIRI

by Keith CowingApril 17, 2025April 17, 2025

The sub-Neptune frontier has opened a new window into the rich diversity of planetary environments beyond the solar system.

The black spectrum represents the best-fitting total emission spectrum of 55 Cancri e from our results.

Astronomy & Telescopes, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Exoplanets, -moons, -comets, Status Report

Characterising the Atmosphere of 55 Cancri e: 1D Forward Model Grid for Current and Future JWST Observations

by Keith CowingMarch 26, 2025

Recent JWST observations with NIRCam and MIRI of the ultra-short-period super-Earth 55 Cancri e indicate a possible volatile atmosphere surrounding the planet. Previous analysis of the NIRCam spectra suggested potential […]

This infrared image from NASA’s James Webb Space Telescope was taken by the onboard Near-Infrared Camera for the JWST Advanced Deep Extragalactic Survey, or JADES, program. The NIRCam data was used to determine which galaxies to study further with spectroscopic observations. One such galaxy, JADES-GS-z14-0 (shown in the pullout), was determined to be at a redshift of 14.3, making it the current record-holder for most distant known galaxy. This corresponds to a time less than 300 million years after the big bang. -- NASA, ESA, CSA, STScI, Brant Robertson (UC Santa Cruz), Ben Johnson (CfA), Sandro Tacchella (Cambridge), Marcia Rieke (University of Arizona), Daniel Eisenstein (CfA), Phill Cargile (CfA)

Astrochemistry, Astronomy & Telescopes, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Imaging & Spectroscopy, Press Release, Stellar Cartography

James Webb Space Telescope Reveals Unexpected Complex Chemistry In A Primordial Galaxy

by Keith CowingMarch 12, 2025March 12, 2025

University of Arizona astronomers have learned more about a surprisingly mature galaxy that existed when the universe was just less than 300 million years old – just 2% of its […]

This artist’s concept shows what the isolated planetary-mass object SIMP 0136 could look like based on recent observations from NASA’s James Webb Space Telescope and previous observations from Hubble, Spitzer, and numerous ground-based telescopes. Researchers used Webb’s NIRSpec (Near-Infrared Spectrograph) and MIRI (Mid-Infrared Instrument) to measure subtle changes in the brightness of infrared light as the object completed two 2.4-hour rotations. -- NASA, ESA, CSA, and Joseph Olmsted (STScI)

Astronomy & Telescopes, Atmospheres, Climate, Weather, Brown Dwarfs, Exoplanets, -moons, -comets, Gas Giants, Icy Worlds, Imaging & Spectroscopy, Press Release

Webb Exposes Complex Atmosphere of Free-Floating Super-Jupiter SIMP 0136

by Keith CowingMarch 4, 2025March 4, 2025

An international team of researchers has discovered that previously observed variations in brightness of a free-floating planetary-mass object known as SIMP 0136 must be the result of a complex combination […]

MIRI

A Saturn-Mass Planet Imaged by Webb Is The Lightest Ever Seen

A Preliminary Search For Planets and Exozodiacal Emission Around Alpha Centauri A with JWST/MIRI

Modern Earth-like Chemical Disequilibrium Biosignatures Are Challenging To Constrain Through Spectroscopic Retrievals

JWST MIRI Imaging Can Directly Detect Exoplanets Of The Same Temperature, Mass, Age, And Orbital Separation As Saturn And Jupiter

A Next-Generation Exoplanet Atmospheric Retrieval Framework for Transmission Spectroscopy (NEXOTRANS): Comparative Characterization for WASP-39 b Using JWST NIRISS, NIRSpec PRISM, and MIRI Observations

Strongest Hints Yet Of Biological Activity Outside Our Solar System

New Constraints On DMS and DMDS In The Atmosphere Of K2-18 b From JWST MIRI

Characterising the Atmosphere of 55 Cancri e: 1D Forward Model Grid for Current and Future JWST Observations

James Webb Space Telescope Reveals Unexpected Complex Chemistry In A Primordial Galaxy

Webb Exposes Complex Atmosphere of Free-Floating Super-Jupiter SIMP 0136

High-CO2 Climates And Observables In The Outer Habitable Zone

Thermally Irreversible Sulfur Chemisorption On Silicate Grains As A Major Sulfur Reservoir In Molecular Clouds

Planetary Eccentricity Enhances Inward Comet Transport But Suppresses Gentle Impacts

Detecting Extragalactic Exoplanets With Fast Radio Burst Nanolensing

Chondrule Size Averaging In Two And Three Dimensions