Making the Invisible Visible
To “see” into the depths of space, the James Webb Space Telescope will have to carry instruments that are sensitive to the infrared wavelength bands of the electromagnetic spectrum.

Infrared wavelengths are a bit longer than the optical wavelengths of the spectrum that are visible to humans. Although we cannot see infrared with the naked eye, we can sense it as heat. Infrared wavelengths are broken down into near, mid, and far infrared.

Engineers, scientists, and the average person make use of infrared technology in everyday life: in security systems, television remote controls, and computers in homes and offices; and in probes for remote diagnostics in industry, science, and the arts.

By studying objects and phenomena in the infrared, astronomers can learn a great deal about our universe’s basic nature. The light from most distant objects in the universe is redshifted and is visible only in infrared wavelengths. Webb will help unveil many secrets about the birth of stars, solar systems, and galaxies in infrared light, which penetrates the interstellar gas and dust that block visible light.

To accomplish this mission, the new Webb observatory will carry four instruments:

• MIRI — a mid-infrared camera/spectrometer, to study distant stellar populations, hydrogen emission at vast distances away, the physics of protostars, and the sizes of faint comets and Kuiper Belt objects in our Solar System
  
  
• NIRCam — a near-infrared camera, to detect light from the earliest stars and galaxies in the process of formation, and to study stellar population in nearby galaxies, young stars in the Milky Way, and Kuiper Belt objects
  
  
• NIRSpec — a multi-object near-infrared spectrometer, capable of observing more than 100 objects simultaneously and designed to study, among other things, star formation and chemical abundances of young distant galaxies.
  
  
• FGS-TF — a tunable filter camera, which can select and focus on extremely specific wavelengths of light out of a huge range of wavelengths, and will be used to study protoplanetary systems and disks, the internal dynamics of galaxies, and the characteristics of elements and molecules in clouds of stellar gas.

The Integrated Science Instrument Module (ISIM) houses Webb's instruments and controls their environment to keep them functioning and safe. Learn more about ISIM at NASA's JWST Web Site.