NASA's James Webb Space Telescope suffers anomaly in one instrument; probe underway

The James Webb Space Telescope has suffered a glitch in one of its instruments which has resulted in a brief halt in observations. NASA revealed that the anomaly has been reported in one of the modes of the Mid-infrared Instrument (MIRI) named medium-resolution spectroscopy (MRS). MIRI has four modes and it suffered a glitch due to a grating wheel which, according to NASA, "exhibited what appears to be increased friction during setup for a science observation".

The grating wheel of MIRI is what allows scientists to select between short, medium, and longer wavelengths of light when making observations using the MRS mode. While in the MRS mode, the James Webb Telescope is able to gather light spectra that have information about the chemical composition of objects from where the light emerges. 

(The four instruments of Webb telescope; Image: NASA)

"The Webb team has paused in scheduling observations using this particular observing mode while they continue to analyze its behaviour and are currently developing strategies to resume MRS observations as soon as possible", an official statement by NASA read. The agency revealed that the observatory is in good health and the rest of the three modes for imaging, low-resolution spectroscopy, and coronagraphy are operational. 

Instruments of Webb telescope

The Webb telescope, which is jointly operated by NASA, European Space Agency (ESA), Canadian Space Agency (CSA) and the Space Telescope Science Institute (STScI), has four instruments in total. Apart from MIRI, Webb is equipped with Near-Infrared Spectrograph (NIRSpec), Near-Infrared Camera (NIRCam) and the Fine Guidance Sensor/Near InfraRed Imager and Slitless Spectrograph (FGS/NIRISS). 

Notably, it is MIRI which requires an operational temperature of -266°C and this is attained by shielding the instrument using Webb's tennis court and special cryocoolers. Interestingly, this number is just seven degrees more than absolute zero. The rest of the three instruments only rely on the sunshields and function at -223°C. 

Webb's latest observational milestone

The observatory's latest observational milestone was photographing Neptune and its rings and offering the clearest views of the planet in over 30 years. Webb was also able to photograph seven of Neptune's Moons including the bright green Triton. Read more about it here.