Skip to main content

One of James Webb’s 17 instrument modes isn’t working

While the James Webb Space Telescope has been both a huge popular success and a highly effective research tool so far, not everything is perfect with the new observatory. This week, NASA announced that one of Webb’s 17 observing modes is not functioning due to a hardware issue that is currently under review.

Webb has four instruments, all of which operate in the infrared portion of the spectrum. Three of the instruments — NIRCam, NIRSpec, and NIRISS — operate in the near-infrared and are working as intended, but there is an issue with the fourth instrument, MIRI, which operates in the mid-infrared.

Each of the instruments can operate in different modes, such as switching between imaging and spectroscopy. There are seventeen of these modes in total, and it is one of MIRI’s modes that is not functioning.

While Webb’s other instruments are useful for cosmology research such as looking back at the earliest galaxies, MIRI, or the Mid-Infrared Instrument, is particularly useful for studying how stars and planets form. Its four modes include an imaging mode for taking pictures of dust and gas throughout galaxies, like a recent image taken of the galaxy Messier 74, and a coronagraphic mode in which light from bright stars can be blocked out to observe the exoplanets which orbit them. It also has two spectroscopy modes, and it is one of these which is not working.

“On August 24, a mechanism that supports one of these modes, known as medium-resolution spectroscopy (MRS), exhibited what appears to be increased friction during setup for a science observation,” NASA wrote in an update. “This mechanism is a grating wheel that allows scientists to select between short, medium, and longer wavelengths when making observations using the MRS mode.”

For now, scientists will not be using the MIRI medium-resolution spectroscopy mode while the issue is investigated. NASA says that an anomaly review board will be deciding on how to move forward and that teams are working on ways that the mode could be brought back into a working state. MIRI’s other three modes are still working fine, so the issue is contained to just the one mode.

Editors' Recommendations

Georgina Torbet
Georgina is the Digital Trends space writer, covering human space exploration, planetary science, and cosmology. She…
James Webb Space Telescope celebrated on new stamps
Two new stamps celebrating the James Webb Space Telescope, issued by the USPS in January 2024.

Two new stamps celebrating the James Webb Space Telescope, issued by the USPS in January 2024. USPS

Beautiful images captured by the James Webb Space Telescope have landed on a new set of stamps issued this week by the U.S. Postal Service (USPS).

Read more
Neptune isn’t really dark blue, new study demonstrates
Voyager 2 took this image as it approached the planet Uranus on Jan. 14, 1986. The planet's hazy bluish color is due to the methane in its atmosphere, which absorbs red wavelengths of light.

Among the most famous images taken by the Voyager spacecraft are those of Uranus and Neptune. When you think of these planets, you're likely imagining them based on the images taken by Voyager 2 in 1986 and 1989, which show the planets as pale greenish blue and royal blue respectively. But a new study shows that the two planets are a very similar color, both closer to a pale baby blue.

Constructing exact color images of space objects is challenging because of how spacecraft cameras typically work. Instead of capturing a color image, cameras typically take a series of black-and-white images using filters corresponding to different wavelengths. Image processors then layer together these black-and-white images to produce a color image.

Read more
James Webb captures a unique view of Uranus’s ring system
This image of Uranus from NIRCam (Near-Infrared Camera) on NASA’s James Webb Space Telescope shows the planet and its rings in new clarity. The Webb image exquisitely captures Uranus’s seasonal north polar cap, including the bright, white, inner cap and the dark lane in the bottom of the polar cap. Uranus’ dim inner and outer rings are also visible in this image, including the elusive Zeta ring—the extremely faint and diffuse ring closest to the planet.

A festive new image from the James Webb Space Telescope has been released, showing the stunning rings of Uranus. Although these rings are hard to see in the visible light wavelength -- which is why you probably don't think of Uranus as having rings like Saturn -- these rings shine out brightly in the infrared wavelength that Webb's instruments operate in.

The image was taken using Webb's NIRCam instrument and shows the rings in even more detail than a previous Webb image of Uranus, which was released earlier this year.

Read more