When Pagan and DePasquale first receive the images, they appear in black and white. The colors are added to the image later, as the data from the various filters are translated into the spectrum of visible light, Pagan explained. The longest wavelengths appear red, while the shorter wavelengths are blue or purple.

"I never dreamed of Webb seeing them in such large numbers."

The James Webb Space Telescope (JWST) has captured the first exquisite images of an interstellar patch of sky, about 11,000 light-years away in the constellation Cassiopeia.