What Webb Learns from Light

The universe is full of clues hidden in light — and Webb has tools to find them.

About 75% of the observations made using NASA's James Webb Space Telescope produce a powerful type of data called spectra — created by separating light into its many colors. Every material interacts with light in a unique way, leaving a distinct pattern of bright or dark lines across the spectrum. By analyzing these patterns through a process called spectroscopy, scientists can uncover details about objects millions or even billions of light-years away, including their temperature, motion, density, and chemical composition.

Webb's infrared spectrographs, which split infrared light into spectra, are the most sensitive ever built. They can detect chemical fingerprints across the cosmos. Since science operations began in 2022, researchers have used this unprecedented capability to transform our understanding of the universe.

In this video, learn about some of the most exciting discoveries Webb has made through spectroscopy — from mapping carbon dioxide on Jupiter's moon Europa, to characterizing the earliest known galaxies, to measuring cloud cover on a distant exoplanet.


Credit: NASA, ESA, CSA, STScI
Producer/Editor: Danielle Kirshenblat
Designer: Leah Hustak
Writer: Danielle Kirshenblat
Additional Scripting: Christopher Britt, Alexander Cotnoir, Leah Hustak
Outreach Scientist: Christopher Britt
Education Specialist: Alexander Cotnoir
Narrator: Ralf Crawford
Special Thanks: Greg Bacon, Margaret W. Carruthers, Quyen Hart
Music courtesy of Universal Music Group.