Comet 67P/C-G is “singing” through space, emitting magnetic field oscillations at 40-50 millihertz, far below human hearing as it rotates. We can hear it now because the recorded magnetic fluctuations were translated into an audio signal and shifted by a factor of approximately 10,000 up into the frequencies the human ear can hear.
Hear it here:
Scientists have picked up on the mysterious “song” of a comet speeding through deep space.
European Space Agency officials have used their Rosetta spacecraft to listen to a sound emitted by Comet 67P/Churyumov-Gerasimenko. The comet song capture by Rosetta is produced by “oscillations in the magnetic field in the comet’s environment,” ESA officials said in a statement.
Read more: Space.com
The sound you can hear is not audio emitted by the comet, rather, an audio translation of detected fluctuations in the comet’s magnetic field. The earth has a “sound” in this way as well.
Using data from NASA’s Time History of Events and Macroscale Interactions during Substorms, or THEMIS, mission, the scientists discovered that when the magnetopause is struck by a jet of plasma from the Sun, it vibrates like a drum, with waves echoing back and forth along its surface, much like they do on top of a drumhead.
Read more EurekaAlert
We can make many different types of data into listenable audio signals. For example, we can “hear” DNA if we translate the four letters of the base pairs (A, T, G, & C) into musical notes.
A human choice to point the notes at a particular virtual instrument can make DNA sound like a piano, like a guitar, drums, trumpet, or whatever. Pointing to a virtual instrument adds a bunch of audio data that was not in the original information.
Sound is a mechanical longitudinal wave emanating from a vibration. It travels (propagates) by bumping adjacent atoms, which in turn bump others, at a certain rate until it reaches your inner ear causing your tympanic membrane to vibrate at this same rate.
Because there are atoms in solids, liquids and gasses, sound can travel through all of these.
It’s an interesting truth that sound you normally experience is the result of mechanical membrane movement in your inner ear being translated into nerve signals your brain uses.
Sound in space is limited by the extreme low density of atoms there.
There is some sound propagation in space, but nothing we could hear.
Space isn’t uniform nothingness. It’s full of stuff. In between the stars, there are clouds of gas and dust. These clouds are sometimes the remains of old stars that went out in a blaze of explosive glory, and they’re the regions where new stars form. And some of that interstellar gas is dense enough to carry sound waves, just not sound perceptible to humans.
Read more Gizmodo
Comet 67P/C-G is “singing” through space. Does it sound like an intelligent signal from aliens to you?
Why does this comet sing?
The magnetic “song” seems to be a consequence of its induced magnetic filled interacting with the solar wind.
Its space environment is permeated by the solar wind – a continuous stream of electrically charged gas (called plasma) and magnetic field lines strung along from the Sun – which interacts with the comet’s gas-dust atmosphere. A consequence of this interaction is an induced cometary magnetosphere. In other words, even though the nucleus of 67P/C-G has no magnetic field of its own (as announced at this year’s EGU General Assembly), the comet’s atmosphere or coma is magnetised.
Read more ESA
In other words, Comet 67P/C-G is telling us what it hears our sun say.
What does the sun say? Today, perhaps, “Happy Mother’s Day!”