MIRI Instrument Archives

October 27, 2023October 27, 2023 by Evan Gough

JWST Sees Four Exoplanets in a Single System

This artist’s rendering shows the star HR 8799 and one of its four planets, HR 8799c. It illustrates the system at an early stage of evolution. It also shows the star's dusty disk and rocky inner planets. Credit: Dunlap Institute for Astronomy & Astrophysics

When the JWST activated its penetrating infrared eyes in July 2022, it faced a massive wish-list of targets compiled by an eager international astronomy community. Distant, early galaxies, nascent planets forming in dusty disks, and the end of the Universe’s dark ages and its first light were on the list. But exoplanets were also on the list, and there were thousands of them beckoning to be studied.

But one distant solar system stood out: HR 8799, a system about 133 light-years away.

October 25, 2023October 26, 2023 by Nancy Atkinson

After DART Smashed Into Dimorphos, What Happened to the Larger Asteroid Didymos?

NASA’s DART mission (Double Asteroid Redirection Test) slammed into asteroid Dimorphos in September 2022, changing its orbital period. Ground and space-based telescopes turned to watch the event unfold, not only to study what happened to the asteroid, but also to help inform planetary defense efforts that might one day be needed to mitigate potential collisions with our planet.

Astronomers have continued to observe and study Dimorphos, well past the impact event. However, Dimorphos is the smaller asteroid in this binary system, and is just a small moon orbiting the larger asteroid Didymos.

The James Webb Space Telescope (JWST) is the only telescope capable of visually distinguishing between the two closely orbiting asteroids. Now, astronomers have made follow-on observations on the system with JWST to see what happened to Didymos after the dust cleared.

October 18, 2023October 18, 2023 by Laurence Tognetti

An Exoplanet so Hot it has Clouds Made of Quartz

Artist illustration showing what WASP-17 b could look like based on data obtained from a myriad of ground- and space-based telescopes, including NASA’s Hubble, Webb, and the retired Spitzer space telescopes. This most recent study used MIRI (Webb’s Mid-Infrared Instrument) to identify nanocrystals of quartz within the clouds WASP-17 b. (Credit: NASA, ESA, CSA, and R. Crawford (STScI))

A recent study published in The Astrophysical Journal Letters used data obtained by the James Webb Space Telescope’s (JWST) Mid-Infrared Instrument (MIRI) to identify the presence of quartz nanocrystals in the upper atmosphere of WASP-17 b, an exoplanet whose mass and radius are approximately 0.78 and 1.87 that of Jupiter, respectively, and is located approximately 1,324 light-years from Earth. WASP-17 b is classified as a “puffy” hot Jupiter due to its 3.7-day orbital period, meaning the extreme temperatures could cause unique chemical processes to occur within its atmosphere, but the astronomers were still surprised by the findings.

June 20, 2023June 20, 2023 by Matt Williams

JWST Glimpses the Cosmic Dawn of the Universe

This still image shows the timeline running from the Big Bang on the right, towards the present on the left. In the middle is the Reionization Period where the initial bubbles caused the cosmic dawn. Credit: NASA SVS

The James Webb Space Telescope (JWST) continues to push the boundaries of astronomy and cosmology, the very job it was created for. First conceived during the 1990s, and with development commencing about a decade later, the purpose of this next-generation telescope is to pick up where Spitzer and the venerable Hubble Space Telescope (HST) left off – examining the infrared Universe and looking farther back in time than ever before. One of the chief objectives of Webb is to observe high-redshift (high-Z) galaxies that formed during Cosmic Dawn.

This period refers to the Epoch of Reionization, where the first galaxies emitted large amounts of ultraviolet (UV) photons that ionized the neutral hydrogen that made up the intergalactic medium (IGM), causing the Universe to become transparent. The best way to measure the level of star formation is the H-alpha emission line, which is visible in the mid-infrared spectrum for galaxies with high redshifts. Using data from the Mid-Infrared Instrument (MIRI), an international team of researchers was able to resolve the H-alpha line and observe galaxies with redshift values higher than seven (z>7) for the first time.

June 20, 2023June 20, 2023 by Nancy Atkinson

The Suspense is Killing Us. The Next Planet in the TRAPPIST System Gets the JWST Treatment

This artist' concept shows what the hot rocky exoplanet TRAPPIST-1 c could look like based on observations by the James Webb Space Telescope. TRAPPIST-1 c, the second of seven known planets in the TRAPPIST-1 system, orbits its star at a distance of 0.016 AU (about 1.5 million miles), completing one circuit in just 2.42 Earth-days. Credits: NASA, ESA, CSA, Joseph Olmsted (STScI)

The TRAPPIST-1 system is easily the most exciting collection of exoplanets ever discovered by astronomers. The system contains seven rocky planets orbiting an ultracool red dwarf star 40 light-years from Earth. Several of the planets are in the star’s habitable zone.

With the James Webb Space Telescope’s ability to detect and study the atmospheres of distant planets orbiting other stars, data on the TRAPPIST planets have been highly anticipated. Astronomers have now released detailed information about the second planet, TRAPPIST-1 c, theorized to be a Venus-like world. Unlike Venus, however, JWST failed to detect any trace of a thick carbon dioxide atmosphere.

April 28, 2023April 28, 2023 by Nancy Atkinson

JWST’s MIRI Instrument is Having Problems Again

JWST's Mid-Infrared Instrument (MIRI is shown here, wrapped in its aluminized thermal shield while being integrated into the JWST Integrated Science Instrument Module (ISIM). Credit: NASA/Goddard Space Flight Center/Chris Gunn

Last week, NASA shared a blog post saying they detected a sensor glitch associated with the James Webb Space Telescope’s Mid-Infrared Instrument (MIRI). For some reason, the sensor for MIRI’s Medium Resolution Spectroscopy (MRS) is receiving less light than expected at the longest wavelengths.

NASA is investigating the cause, and said that the instrument is not at risk and no effect has been seen for images taken by MIRI. According to agency officials, all other modes of JWST and MIRI remain unaffected, and they are searching for the underlying issue.

February 17, 2023February 17, 2023 by Evan Gough

Galaxies Aren’t Just Stars. They’re Intricate Networks of Gas and Dust

This image taken by the NASA/ESA/CSA James Webb Space Telescope shows the spiral galaxy NGC 1433. Image Credit: NASA, ESA, CSA, and J. Lee (NOIRLab), A. Pagan (STScI)

Astronomers have studied the star formation process for decades. As we get more and more capable telescopes, the intricate details of one of nature’s most fascinating processes become clearer. The earliest stages of star formation happen inside a dense veil of gas and dust that stymies our observations.

But the James Webb Space Telescope sees right through the veil in its images of nearby galaxies.

February 6, 2023February 6, 2023 by Nancy Atkinson

JWST Unexpectedly Finds a Small Asteroid During ‘Failed’ Observations

Illustration of Asteroid (Artist’s Impression). Credit: N. Bartmann (ESA/Webb), ESO/M. Kornmesser and S. Brunier, N. Risinger

While astronomers and engineers were trying to calibrate one of the James Webb Space Telescope’s instruments last summer, they serendipitously found a previously unknown small 100–200-meter (300-600 ft) asteroid in the main asteroid belt. Originally, the astronomers deemed the calibrations as a failed attempt because of technical glitches. But they noticed the asteroid while going through their data from the Mid-InfraRed Instrument (MIRI), and ended up finding what is likely the smallest object observed to date by JWST. It is also one of the smallest objects ever detected in our Solar System’s main belt of asteroids.

“We — completely unexpectedly — detected a small asteroid in publicly available MIRI calibration observations,” explained Thomas Müller, an astronomer at the Max Planck Institute for Extraterrestrial Physics in Germany, in a press release. “The measurements are some of the first MIRI measurements targeting the ecliptic plane and our work suggests that many, new objects will be detected with this instrument.”

November 10, 2022November 10, 2022 by Nancy Atkinson

Woohoo! JWST's Mid-Infrared Instrument is Fully Operational Again

pillars of creation — The NASA/ESA/CSA James Webb Space Telescope’s mid-infrared view of the Pillars of Creation. Credit: NASA, ESA, CSA, STScI, J. DePasquale (STScI), A. Pagan (STScI)

Engineers with the James Webb Space Telescope have figured out a way to work around a friction issue that arose with the telescopes’ Mid-Infrared Instrument (MIRI). The team is now planning to resume observations with the instrument’s medium resolution spectrometry (MRS) mode, which has not been used since August.

August 18, 2022August 18, 2022 by Matt Williams

A New Image From Webb Shows Galaxy NGC 1365, Known to Have an Actively Feeding Supermassive Black Hole

The barred spiral galaxy NGC 1365. Credit: NASA/JPL-Caltech/Judy Schmidt

The James Webb Space Telescope continues to deliver stunning images of the Universe, demonstrating that the years of development and delays were well worth the wait! The latest comes from Judy Schmidt (aka. Geckzilla, SpaceGeck), an astrophotographer who processed an image taken by Webb of the barred spiral galaxy NGC 1365. Also known as the Great Barred Spiral Galaxy, NGC 1365 is a double-barred spiral galaxy consisting of a long bar and a smaller barred structure located about 56 million light-years away in the southern constellation Fornax.