Hear the sound file.

This tone represents sound waves that traveled through the early universe, and were later "heard" by the Planck space telescope. The primordial sound waves have been translated into frequencies we can hear.

They sound like a constant humming and are made up of a primary wave (the lowest tone) and higher overtones. The "whooshing" oscillation sounds you hear were produced during the processing to make this sound file.

Before there were any stars or galaxies, 13.8 billion years ago, our universe was just a ball of hot plasma -- a mixture of electrons, protons, and light. Sound waves shook this infant universe, triggered by minute, or "quantum," fluctuations happening just moments after the big bang that created our universe.

As these sound waves propagated through the young universe, they left imprints on the matter and light, much like patterns made by waves on the surface of a pond into which a stone has been dropped. These patterns were imprinted as slightly brighter and darker patches in the light. By mapping this ancient light that has traveled to us through space and time, Planck can essentially see the sound echoes of the early universe.

For this sound file, the patterns in the sky observed by Planck have been translated to audible frequencies. This sound mapping represents a 50-octave compression in going from the actual wavelengths of the primordial sound waves (around 450,000 light-years, or around 47 octaves below the lowest note on the piano) to wavelengths we can hear.

Planck is a European Space Agency mission, with significant participation from NASA. NASA's Planck Project Office is based at NASA's Jet Propulsion Laboratory, Pasadena, Calif. JPL contributed mission-enabling technology for both of Planck's science instruments. European, Canadian and U.S. Planck scientists work together to analyze the Planck data.

More information is online at http://www.nasa.gov/planck, http://planck.caltech.edu and http://www.esa.int/planck .

Photojournal note:This image was originally released on January 17, 2013 and can be seen at PIA13953. It is being re-released today to present the sound file (see link above).