The Mid-Infrared Instrument is a camera and spectrograph on the James Webb Space Telescope.MIRI, the Mid-Infrared Instrument, is one of four scientific instruments aboard the James Webb Space Telescope (JWST). It is the only instrument on JWST that detects light in the mid-infrared range, roughly 5 to 28 micrometers in wavelength. This part of the spectrum is invisible to the human eye and is primarily associated with heat radiation, making MIRI essential for observing cool objects like distant galaxies, forming stars, and exoplanet atmospheres.
MIRI was developed jointly by a European consortium of 10 countries and NASA's Jet Propulsion Laboratory, with the design finalized in the early 2000s and the instrument delivered in 2012. It was launched into space aboard JWST in December 2021.
MIRI combines a camera and a spectrograph. The camera captures images in the mid-infrared, while the spectrograph splits the incoming light into its component wavelengths, revealing the chemical fingerprints of gases and solids. To detect such long-wavelength light, MIRI must be kept extremely cold—below 7 Kelvin—using a dedicated cryocooler, because the instrument's own heat would otherwise swamp the faint signals. The detector is a special array of arsenic-doped silicon that converts incoming infrared photons into electrical signals.
MIRI is used to study the atmospheres of exoplanets, the formation of stars and planetary systems, and the earliest galaxies in the universe, providing data that is impossible to obtain from ground-based telescopes.
MIRI's detector is so sensitive that it can detect the heat of a single bumblebee at the distance of the Moon.
























