November 13 is the 317th day of the year. You know what else is 317? The number of miles, in millions, travelled by the Rosetta orbiter, which delivered the Philae lander to the comet it then landed on (thus fulfilling its destiny). Landing a little robot scientist on a comet is a pretty fancy feat, and the lander’s sensors are taking in reams of data for scientists back home to study, although it doesn’t have long to live: poor lil Philae is solar-powered, but it landed in the shadow of a cliff, so its battery may not even last the intended 60 hours. Meanwhile, the Rosetta orbiter, launched years ago by the European Space Agency, has been doing its own data gathering and has revealed that the comet is sort of humming to itself as it wheels slowly through space. ClassicFM.com puts it beautifully:
Comet 67P/Churyumov-Gerasimenko, to give it its full name, is a rubber duck-shaped celestial body more than four billion years old. Earlier this week…Philae ended its aeons of isolation by making a historic, if slightly awkward, landing…
The mission has already contributed greatly to our understanding of comets – and one discovery is of great interest to music lovers: scientists have revealed that the comet has been singing for four billion years…
So, how does a comet vocalise? Oscillations in the magnetic field of Comet 67P are creating a sound at a wavelength of around 40-50 millihertz, far below the range of human hearing. ESA scientists have increased the frequency by a factor of 10,000 in order to hear the song.
Karl-Heinz Glaßmeier, head of Space Physics and Space Sensorics at the Technische Universität Braunschweig, Germany, says they are still trying to work out what is happening, but adds: “This is exciting because it is completely new to us.”
That’s interesting, because after playing it in Classic FM towers, it didn’t sound particularly new to us.
In fact, the the classical music folks hear a distinct similarity between the comet’s magnetic oscillations and Continuum for Harpsichord, an intense and abstract piece by 20th-century Hungarian composer Gyorgy Ligeti. The site provides both songs for you to listen to: go judge for yourself.