Credit: NASA, ESA, CSA, STScI, Jacob Jencson (Caltech/IPAC); Image Processing: Joseph DePasquale (STScI)

These shimmering cosmic curtains show interstellar gas and dust that has been heated by the flashbulb explosion of a long-ago supernova. The gas then glows infrared light in what is known as a thermal light echo. As the supernova illumination travels through space at the speed of light, the echo appears to expand. NASA’s James Webb Space Telescope observed this light echo in the vicinity of the supernova remnant Cassiopeia A three separate times, in essence creating a 3D scan of the interstellar material. Note that the field of view in the top row is rotated slightly clockwise relative to the middle and bottom rows, due to the roll angle of the Webb telescope when the observations were taken.

Provider: Space Telescope Science Institute

Image Source: https://webbtelescope.org/contents/news-releases/2025/news-2025-102

Curator: STScI, Baltimore, MD, USA

Image Use Policy: http://stsci.edu/copyright/