A black hole is about the last thing you’d expect to hear. Space is nearly empty, and the famous NASA audio sounds as though somebody gave the universe a rather ominous bass note.

So how does one hear a black hole sound? Scientists can measure ripples in gas around one black hole, then shift the measured frequencies into an audible range. Other recordings turn telescope images into sound by a different method. The distinction makes the audio much more interesting than a spooky clip.

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Can a black hole make a sound?

Sound needs something to travel through. When a speaker plays music, it pushes air back and forth. Those changes in pressure travel to your ears, where they become something you can hear.

The space vacuum around most black holes has far too little matter to carry sound to a listener. You couldn’t put a microphone beside a black hole, run a cable back to Earth, and expect a recording. There’d be nobody in the studio to say, “Let’s try that again,” either.

But space isn’t equally empty everywhere. The Sun sends particles through our solar system, while some galaxy clusters contain enormous clouds of thin, hot gas. Sound waves need matter to travel through, and they can move through that gas, even though no person nearby could hear them unaided.

A black hole can disturb its surroundings, and astronomers can measure the disturbance. That’s the short answer: we hear a translation of what telescopes detect, played through an ordinary speaker on Earth.

How the black hole sound in Perseus became audible

The clip most people mean comes from the Perseus galaxy cluster, roughly 250 million light-years away. Its central galaxy contains a supermassive black hole surrounded by hot gas that emits X-rays.

What Chandra found in the gas

NASA’s Chandra X-ray Observatory detected ripples spreading through the cluster’s gas. Activity associated with the central black hole, including jets that push material outward, disturbs the surrounding gas.

Picture tapping the side of a bathtub and watching ripples spread across the water. The Perseus ripples aren’t water waves, and their scale is hard to picture, but the useful idea is the same: a disturbance travels through a material. Here, that material is gas between galaxies.

Chandra’s Perseus cluster sonification is based on observed pressure waves. That matters because the underlying phenomenon really is sound moving through gas, although its pace and pitch are far outside our everyday experience.

What NASA put into the recording

Chandra observed the gas through X-rays, not through a microphone. Researchers identified the ripples in those observations and translated their frequencies into sounds a speaker can play.

So the clip isn’t raw audio captured at Perseus. It also isn’t a random musical mood assigned to a black hole. It has a measurable physical starting point, followed by a large and necessary change of scale.

Why the original pitch is impossible to hear

The pressure waves in Perseus are extraordinarily low-pitched. Their characteristic note sits about 57 octaves below middle C. If middle C is a comfortable piano note, Perseus is nowhere near the bottom of the keyboard.

The frequency is too low for human hearing

Pitch depends on how often a wave repeats. Our ears handle vibrations that cycle many times each second. A Perseus pressure wave takes millions of years to complete a cycle.

Distance isn’t the only obstacle, then. Even if you could somehow stand in the cluster’s gas, your ears wouldn’t turn that slow change in pressure into a note. You’d need an instrument capable of measuring the wave and a way to translate its frequency.

How the measured waves were shifted

For the released Perseus audio, the measured wave cycles were raised by factors of 144 quadrillion and 288 quadrillion. Those aren’t volume settings. They shift the waves into a range people can hear.

Think of time-lapse photography. A flower may open too slowly for you to notice while watching it, but speeding up the footage reveals the movement. The Perseus audio does something similar with a slow vibration. What you hear preserves a relationship to the measured ripples, while playing them at their original frequency would tell your ears nothing.

The surprising part isn’t that Perseus sounds eerie. It’s that gas between galaxies can carry a pressure wave at all.

How astronomers turn telescope data into sound

Perseus has a physical sound wave behind its audio. Many other space sonifications begin with light or radio observations instead. Both are useful, but they’re different kinds of listening.

Measurements need a set of musical rules

Data sonification maps astronomical data, including electromagnetic data from light or radio observations, to audible properties. A sonification might make brighter regions louder, while assigning different pitches to positions or types of light.

Some projects move across an image over a few seconds, so your ear encounters features in sequence. Others let several layers play together. NASA’s Hubble sonification examples show how brightness and position can become parts of an audio piece.

There isn’t one universal conversion, like changing miles to kilometers. Projects such as SYSTEM Sounds make deliberate mapping choices, and those rules determine what listeners can notice.

Radio waves aren’t already radio music

Astronomers call radio waves “waves,” which makes the confusion understandable. Radio waves are electromagnetic radiation, like visible light or X-rays. Sound waves are changes in pressure moving through matter.

A radio telescope measures radio waves, a form of electromagnetic radiation; it doesn’t hear a celestial broadcast through the air. Turning its measurements into audio requires a mapping chosen by people. You can learn from the result without mistaking it for a recording of what space would sound like to human ears.

What M87 reveals about a black hole

The galaxy M87 offers a useful comparison with Perseus. Its central black hole featured in the first black-hole shadow image, released by the Event Horizon Telescope collaboration in 2019. It also has a powerful jet that astronomers study across several kinds of light.

Three observatories, three views

The audio piece combines observations from the Chandra X-ray Observatory, the Hubble Space Telescope and the Atacama Large Millimeter/submillimeter Array, or ALMA. Chandra supplies X-ray data, the Hubble Space Telescope provides optical observations, and ALMA supplies radio observations.

Each instrument picks up something the others don’t show in the same way. Combining them gives listeners a way to encounter several views of the same galaxy. Chandra’s black hole sonification release presents it alongside the Perseus audio.

Why M87 sounds different from Perseus

The audio piece translates telescope data across an image into audible tones. It doesn’t start with a measured pressure wave in gas like the Perseus piece does. If you hear different pitches as the audio progresses, you’re hearing the rules used to represent the observations.

That’s a useful distinction when someone shares a clip titled “the sound of a black hole.” Ask what was measured first. Was it a pressure wave, or was it light mapped to notes? Both can tell you something about the object, but they answer different questions.

What listening adds to astronomy

Astronomy usually arrives as a picture. That works well for many people, but an image is only one way to examine data. Sound can give changes in brightness, position or structure a different form that listeners may notice.

The people behind the sound

Chandra visualization scientist Kimberly Arcand has worked with astrophysicist and musician Matt Russo, and musician and sound engineer Andrew Santaguida of SYSTEM Sounds, on the A Universe of Sound project. SYSTEM Sounds helps turn astronomical measurements into carefully designed listening experiences.

The A Universe of Sound collection lets you compare objects instead of treating one viral clip as the whole story. Listening to several makes the differences clearer: a note may come from a physical pressure wave, or it may represent a feature in telescope data.

Access matters beyond the novelty

For someone who cannot see a telescope image, audio offers another way into the observation. It can also help a group discuss where an image gets brighter or how different observations overlap. A published account of the project describes efforts to create audio representations of astronomical data for wider audiences.

Sonification doesn’t make every detail of an image audible, and one audio design won’t work equally well for every listener. It gives astronomy another useful way to share evidence. The spooky sound is memorable; the access it creates deserves attention too.

Key takeaways

The famous Perseus audio begins with real ripples in hot gas around a galaxy cluster’s central black hole. Chandra measured them, and their pitch was raised enormously so we could hear them.

Other black hole audio, including M87’s, can start with telescope observations of light rather than physical sound waves. In either case, listening means hearing a carefully chosen translation of data, not a microphone recording brought home from space.

Questions people ask about black hole sounds

Did NASA record a black hole with a microphone?

No. The Perseus clip comes from X-ray observations of pressure ripples in gas. Researchers converted the measured waves into audible sound. A microphone floating in the near-vacuum of space wouldn’t capture that clip.

Is the Perseus sound the noise of matter falling in?

The audio represents pressure waves in gas surrounding the cluster’s central black hole. Activity associated with the black hole disturbs that gas. The clip doesn’t let us hear matter cross the event horizon, the boundary beyond which light cannot escape.

Can I hear the original Perseus note?

Your ears can’t detect it at its original frequency, about 57 octaves below middle C. The available recording raises its frequencies into an audible range. You hear a translated version of the pattern rather than the original, millions-of-years-long vibration.

Are all NASA space sounds made the same way?

No. The Perseus clip begins with a physical pressure wave, while its sonification turns measurements into audible sound. Image-based examples assign sounds to telescope observations across an image. Checking how each one was made is the easiest way to understand what you’re hearing.

A sound that needs translating

You can’t hear a black hole by listening into empty space. You can hear what its activity does to nearby gas, once scientists measure a wave and raise its pitch. You can also hear telescope data given a thoughtful set of sound rules.

That low Perseus note earned its place in your headphones through an extraordinary chain of measurement. The black hole never needed a microphone.