The Mid-Infrared instrument (MIRI), the second of NASA’s four primary scientific instruments on the James Webb Space Telescope, has completed its postlaunch preparations and is now ready for science.
The final MIRI mode to be checked was its coronagraphic imaging capability, which uses two types of masks to intentionally block starlight from hitting its sensors when attempting to observe the star’s orbiting planets. These customized masks enable scientists to directly detect exoplanets and study dust discs around their host stars in unprecedented ways.
MIRI, along with Webb’s three other instruments, initially cooled to about 90 Kelvin in the shade of Webb’s tennis-court-size sunshield (minus 298 degrees Fahrenheit, or minus 183 degrees Celsius). Using an electrically powered cryocooler, the temperature was reduced to less than 7 Kelvin—just a few degrees above the lowest temperature matter can reach. MIRI can deliver mid-infrared images and spectra with an unprecedented combination of sharpness and sensitivity thanks to its extreme operating temperatures.
“We are overjoyed that MIRI is now a fully operational, cutting-edge instrument that outperforms expectations in all areas. Our multinational commissioning team has done an outstanding job in completing MIRI in a matter of weeks. Now we celebrate all the people, scientists, engineers, managers, national agencies, ESA, and NASA, who have helped make this instrument a reality, as MIRI begins to explore the infrared universe in new ways and to new depths “Gillian Wright, MIRI European principal investigator at the UK Astronomy Technology Centre, and George Rieke, MIRI science lead at the University of Arizona, both contributed to the announcement.MIRI was created as a collaboration between NASA and ESA, with NASA’s Jet Propulsion Laboratory leading the US effort and a multi-national consortium of European astronomical institutes contributing for ESA.
With the post-launch commissioning of NIRISS and MIRI completed, the Webb team will continue to focus on testing the remaining two modes on its other instruments. On July 12, 2022, NASA’s James Webb Space Telescope, a collaboration with ESA and CSA, will release its first full-color images and spectroscopic data.