NASA's Voyager 1 spacecraft captured these sounds of interstellar space.
Voyager 1's plasma wave instrument detected the vibrations of dense
interstellar plasma, or ionized gas, from October to November 2012 and
April to May 2013.
The graphic shows the frequency of the waves,
which indicate the density of the plasma. Colors indicate the intensity
of the waves, or how "loud" they are. Red indicates the loudest waves
and blue indicates the weakest.
The soundtrack reproduces the
amplitude and frequency of the plasma waves as "heard" by Voyager 1. The
waves detected by the instrument antennas can be simply amplified and
played through a speaker. These frequencies are within the range heard
by human ears.
Scientists noticed that each occurrence involved a
rising tone. The dashed line indicates that the rising tones follow the
same slope. This means a continuously increasing density.
scientists extrapolated this line even further back in time (not shown),
they deduced that Voyager 1 first encountered interstellar plasma in
The Voyager spacecraft were built and continue to be
operated by NASA's Jet Propulsion Laboratory, in Pasadena, Calif.
Caltech manages JPL for NASA. The Voyager missions are a part of NASA's
Heliophysics System Observatory, sponsored by the Heliophysics Division
of the Science Mission Directorate at NASA Headquarters in Washington.