Credit: NASA/JPL-Caltech/H. Dole (IAS)

Coaxing out a signal: this graphic demonstrates how the 24 micron images (shown in blue) of over 20,000 faint galaxies were added up to create a detectable signal at longer wavelengths. In each individual observation, the galaxy is barely visible at 24 microns and invisible at longer wavelengths. When the observations are combined, however, the longer-wavelength images emerge.