MIRI will observe light in the mid-infrared range of 5 microns to 28 microns, NASA says. That's a longer wavelength than humans can see. "MIRI will enable Webb to distinguish the oldest galaxies from more evolved objects that have undergone several cycles of star birth and death," Goddard project scientist Matt Greenhouse said."MIRI also will provide a unique window into the birth places of stars which are typically enshrouded by dust that shorter wavelength light cannot penetrate."
NASA said MIRI will be able to observe cool stars in distant galaxies, newly forming stars in the Milky Way and find "signatures" of planets around other suns. The instrument was assembled at the Science and Technology Facilities Council's Rutherford Appleton Laboratory in the United Kingdom after being developed by a team of European institutions and NASA's Jet Propulsion Laboratory.
The Webb telescope will be the most powerful space telescope ever built. It is a joint project of NASA, the European Space Agency and the Canadian Space Agency. To see "behind the Webb" videos, click here and here. To learn more about the mid- and near-infrared spectrum, click here.