George Rieke, MIRI Science Team Lead at University of Arizona, Tucson, noted, "MIRI is the first Webb instrument to be delivered, the result of teamwork in the U.S. and internationally."

MIRI will observe light with wavelengths in the mid-infrared range of 5 microns to 28 microns, which is a longer wavelength than human eyes can detect. It is the only instrument of the four with this particular ability to observe the physical processes occurring in the cosmos.

"MIRI will enable Webb to distinguish the oldest galaxies from more evolved objects that have undergone several cycles of star birth and death," said Matt Greenhouse, ISIM project scientist at Goddard. "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."

MIRI's sensitive detectors will allow it to observe light, cool stars in very distant galaxies; unveil newly forming stars within our Milky Way; find signatures of the formation of planets around stars other than our own; and take imagery and spectroscopy of planets, comets and the outermost bits of debris in our solar system. MIRI's images will enable scientists to study an object's shape and structure.

"MIRI will help us understand what's out there at the edge of what we can see," said Mike Ressler, the instrument's project scientist at NASA's Jet Propulsion Laboratory in Pasadena, Calif.

"The shorter-wavelength instruments will discover the glow of the farthest known objects, but we need MIRI to help identify what they are - supermassive black holes, newborn galaxies or something we've never seen before."

The most powerful space telescope ever built, Webb is the successor to NASA's Hubble Space Telescope. Webb's four instruments will reveal how the universe evolved from the Big Bang to the formation of our solar system. Webb is a joint project of NASA, the European Space Agency and the Canadian Space Agency.