For anyone who is a hardcore J.R.R. Tolkien fan and has read The Silmarillion way too many times, you probably remember the opening chapter when gods otherwise known as the Ainur sing the world into being. Tolkien must have been onto something. The universe does make a sort of music.
Unless we find a way to travel at the speed of light—which we won’t be doing anytime soon—no one is actually witnessing cosmic landmarks up close. What could (at least virtually) take us there is sonification. We depend on data from telescopes and satellites to tell us the position, brightness, chemical makeup, and other properties of our galactic center and objects beyond Earth, such as supernovae and neutron stars. Sonification translates this data into sound. Now sonified versions of data collected by NASA’s Chandra X-ray Observatory, Hubble Space Telescope, and Spitzer Space telescope have been turned into something you can listen to through your earpods.
Even cooler is that you can listen to the sonified data as “solos” or an “orchestra” with a different instrument playing the data from each telescope.
The supernova remnant Cassiopeia A (Cas A), 11,00 light years away in the galaxy Messier 16, has had several elements sonified individually and together. Separate elements found within the exploded star have their own musical signatures. Sulfur (yellow) is a midtone sound that regularly crescendos and diminishes like a starship powering up and then slowing down. Calcium (green) is a similar sound that registers slightly higher. Iron (purple) is the type of mid-high pitch you tend to hear in a movie scene on the brink of adventure. Blast wave energy (blue) is the highest, as opposed to silicon (red), a low drone that gives you the sort of dread inspired by something lurking in the darkness of the void. Cas A as a symphony could easily inspire the next Star Trek intro.
The different elements and phenomena in Cas A sound the way they do because of how light and energy translate from visuals to something audible. Sonic translation goes from left to right. Light from objects near the top of the image makes the pitch go up or down, while the intensity of that light does the same with the volume. The high pitch of blast wave energy is obvious. Cas A’s symphony could be even more complex if the less abundant elements in the remnant, such as carbon, nitrogen, phosphorus, and hydrogen, were translated, but something huge is missing from this song. That would be oxygen. Unfortunately, even though oxygen is the most abundant element in Cas A, at 65%, its X-ray emissions encompass so many types of energies that it would make them extremely difficult to isolate and sonify.
You don’t need to rocket 7,000 years away if you’re more in the mood to listen to the iconic Pillars of Creation (top). The pitch of this nebula, so popular it even exists in the form of leggings, depends on how light is vertically positioned, but unlike Cas A, the variance in this nebula results in a range of pitches as the translation moves from left to right. There are two different melodies that combine into what can only be described as how you might imagine a space storm. Each of these melodies are based on different kinds of light. It is the sonic version of X-ray light that gives it that alien vibe, while optical light is that windy, stormy sound you hear.
So what kind of “music” does our own galactic center emit from 26,000 light years away? You’ll have to listen to it for yourself (above), but if the sparkle of stars had a sound, this would be it.