Skip to main content

One of James Webb’s four instruments is offline following error

The James Webb Space Telescope is experiencing an issue with one of its instruments, the Near Infrared Imager and Slitless Spectrograph, or NIRISS. The instrument is currently offline with no indication of when it will be back online, but engineers are working to address the issue and the telescope hardware remains safe.

As alarming as that might sound, it is not uncommon for such issues to crop up, especially in space telescopes. As performing physical maintenance on space telescopes is extremely difficult, software troubleshooting is done in a slow and careful way to prevent any damage from occurring. That’s why you’ll see instruments on space telescopes like Hubble or the Swift Observatory going into safe mode to protect themselves whenever an issue arises.

Related Videos

In the case of James Webb, the problem with the NIRISS instrument was due to a communication delay. “On Sunday, Jan. 15, the James Webb Space Telescope’s Near Infrared Imager and Slitless Spectrograph (NIRISS) experienced a communications delay within the instrument, causing its flight software to time out,” NASA wrote in a statement. “The instrument is currently unavailable for science observations while NASA and the Canadian Space Agency (CSA) work together to determine and correct the root cause of the delay.”

NIRISS sits alongside a sensor called the Fine Guidance Sensor or FGS which allows the telescope to point at its targets accurately. NIRISS can work as both a camera and a spectrograph and has a special feature called an aperture mask which allows it to block out light from particularly bright sources to better see dimmer sources around them. The instrument is used for tasks like detecting and examining exoplanets and for looking at distant galaxies.

The planned scientific observations which were scheduled to use NIRISS will now be rescheduled, according to NASA.

This comes on the heels of another issue with Webb which occurred in December 2022. A software issue in the attitude control system caused some instruments to enter safe mode on December 7, with science observations being paused. That was fixed by December 20, when all science operations resumed.

Editors' Recommendations

A failed Webb telescope calibration leads to the discovery of this tiny asteroid
An asteroid roughly the size of Rome’s Colosseum — between 300 to 650 feet (100 to 200 meters) in length — has been detected by an international team of European astronomers using NASA's James Webb Space Telescope. They used data from the calibration of the MIRI instrument, in which the team serendipitously detected an interloping asteroid. The object is likely the smallest observed to date by Webb and may be an example of an object measuring under 1 kilometer in length within the main asteroid belt, located between Mars and Jupiter. More observations are needed to better characterize this object’s nature and properties.

With any new technology, there are bound to be failures -- and that's true of cutting-edge astronomy instruments like the James Webb Space Telescope as well. But failures can have a silver lining, as was demonstrated recently when an unsuccessful attempt to calibrate a Webb instrument to a well-known asteroid turned up a delightful surprise: the discovery of a new, different asteroid that is just a few hundred feet across.

An asteroid roughly the size of Rome’s Colosseum — between 300 to 650 feet in length — has been detected by a team of European astronomers using NASA's James Webb Space Telescope. They used data from the calibration of the MIRI instrument to serendipitously detect an interloping asteroid. The object is likely the smallest observed by Webb, and may be an example of an object measuring under 1 kilometer in length within the main asteroid belt, located between Mars and Jupiter.  ARTWORK: NASA, ESA, CSA, N. Bartmann (ESA/Webb), Martin Kornmesser (ESA), Serge Brunier (ESO), Nick Risinger (Photopic Sky Survey)

Read more
See a stunning field of galaxies captured by James Webb Space Telescope
A crowded field of galaxies throngs this Picture of the Month from the NASA/ESA/CSA James Webb Space Telescope, along with bright stars crowned with Webb’s signature six-pointed diffraction spikes. The large spiral galaxy at the base of this image is accompanied by a profusion of smaller, more distant galaxies which range from fully-fledged spirals to mere bright smudges. Named LEDA 2046648, it is situated a little over a billion light-years from Earth, in the constellation Hercules.

Stunning images from the James Webb Space Telescope continue to entrance, and recently the researchers using the telescope have shared a gorgeous image of a field of galaxies as part of the Webb Picture of the Month collection.

The image shows a spattering of different background galaxies, while the foreground shows bright individual stars and a bright spiral galaxy at the bottom called LEDA 2046648. Located around a billion light-years from Earth, this galaxy is relatively much closer to us than the far-off background galaxies which is why it is so prominent in the image.

Read more
James Webb peers into icy cloud to learn about exoplanet formation
This image by the NASA/ESA/CSA James Webb Space Telescope’s Near-InfraRed Camera (NIRCam) features the central region of the Chameleon I dark molecular cloud, which resides 630 light years away. The cold, wispy cloud material (blue, centre) is illuminated in the infrared by the glow of the young, outflowing protostar Ced 110 IRS 4 (orange, upper left). The light from numerous background stars, seen as orange dots behind the cloud, can be used to detect ices in the cloud, which absorb the starlight passing through them.

Here's how to build an exoplanet: You start off with a star that's surrounded by a disk of dust and gas. As the star burns and sends out gusts of stellar wind, the dust in the disk begins to interact and form into clumps. These clumps attract more dust, turning into pebbles, and then into rocks, and the gas helps these rocks stick together. They grow, picking up more and more material and clearing their orbit around the star. These are the first stage of planetary development, called planetesimals.

There's another important ingredient for growing a planet, though: ice. In the cold clouds of dust and gas, ice forms as a kind of frost on dust grains. These icy grains carry some of the key ingredients for a potentially habitable planet, like carbon, hydrogen, and oxygen. Here on Earth, it's thought that some of these ingredients could have been brought to our planet by icy comets, but in other systems, these ices could have been present as the exoplanets formed.

Read more