'Milky Way Blues': Listen to the Strange Jazzy Sounds of our Galaxy Rotating

An astronomer has created a two-minute piece of music which expresses the movement of gases in the Milky Way galaxy as it rotates—and it sounds like a strange form of jazz.

Mark Heyer, from the University of Massachusetts Amherst, developed an algorithm which enabled him to take 20 years of radio telescope data on these gases and map it onto musical notes in the pentatonic scale that were then played by various digital instruments.

He dubbed the resulting composition—which took several months to craft—“Milky Way Blues.” It is currently being featured on the website Astronomy Sound of the Month.

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Milky Way is seen during the annual Perseid meteor shower above Salime Reservoir, near Grandas de Salime, Spain August 11, 2017. An astronomer has created a piece of music which expresses the movement of gases in the Milky Way as it rotates. REUTERS/Paul Hanna

“This musical expression lets you ‘hear' the motions of our Milky Way galaxy,” Heyer said in a statement. “The notes primarily reflect the velocities of the gas rotating around the center of our galaxy.”

To produce the piece, Heyer took various astronomical data points and assigned them to different aspects of the song, without editing the melodies and rhythms.

“I've been true to the data, I haven't massaged it to make it sound nice, but by turning what we actually observe with a radio telescope into a musical scale it gives us familiar tones that sound surprisingly like music with which we're familiar,” he said.

In galaxies, the regions in between stars are filled with gas that exists in three phases, known as atomic, molecular and ionized. Heyer assigned data from each of these phases to different instruments: Molecular gas was translated into woodblocks and piano; atomic gas was turned into acoustic bass; and ionized gas was transformed into saxophone.

He then determined the pitch and length of each note depending on the velocity and intensity of emissions measured from these different gases. Higher notes represent gases that are moving towards Earth, while low notes are gases that are moving away from our planet. Meanwhile, gases with more intense emissions are played longer than those with weaker emissions.

Heyer said one the main reasons for creating the composition was to illustrate the dynamic motion of the Milky Way, something that images of our galaxy fail to illustrate.

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Astronomer Mark Heyer. University of Massachusetts Amherst

Amherst also notes that he's not the first researcher to show an interest in the relationship between astronomy and music.

“Johannes Kepler 400 years ago wrote Harmonies of the World that described the elliptical orbits of planets around the Sun and assigned musical notes based on orbital velocities,” he said.

These attempts echo the ancient philosophical concept called “Music of the Spheres” or “Musica universalis” which likens the movements of celestial bodies to a form of music (although this music is not audible but a mathematical, harmonic or spiritual concept).