Spitzer, 25 hour per band
(GOODS collaboration)

The Spitzer Space Telescope is currently NASA's most powerful infrared observatory. This is one of Spitzer's deepest images into space, showing galaxies that existed about a billion years after the Big Bang.

JWST, 1000s per band
(simulated)

JWST's larger mirror and more advanced instruments will be able to show distant galaxies in much greater detail, as shown in this simulated image. Visible along with the prominent galaxies in this image are tiny, reddish specks that are galaxies that formed when the Universe was only a few hundred million years old.