The European Space Agency launched the satellite Rosetta back in 2004, and it recently reached one of its targets, a space rock named Comet 67P/Churyumov-Gerasimenko.
Upon reaching the comet, the Rosetta orbiter sent back something surprising to scientists—a “song” created in “the form of oscillations in the magnetic field in the comet's environment." Listen to Rosetta’s “singing comet” below, and let us know your thoughts.
The ESA reports:
"Rosetta's Plasma Consortium (RPC) consists of five instruments on the Rosetta orbiter that provide a wide variety of complementary information about the plasma environment surrounding Comet 67P/C-G. [...] The instruments are designed to study a number of phenomena, including: the interaction of 67P/C-G with the solar wind, a continuous stream of plasma emitted by the Sun; changes of activity on the comet; the structure and dynamics of the comet's tenuous plasma 'atmosphere', known as the coma; and the physical properties of the cometary nucleus and surface.
But one observation has taken the RPC scientists somewhat by surprise. The comet seems to be emitting a 'song' in the form of oscillations in the magnetic field in the comet's environment. It is being sung at 40-50 millihertz, far below human hearing, which typically picks up sound between 20 Hz and 20 kHz. To make the music audible to the human ear, the frequencies have been increased by a factor of about 10,000.
The music was heard clearly by the magnetometer experiment (RPC-Mag) for the first time in August, when Rosetta drew to within 100 km of 67P/C-G. The scientists think it must be produced in some way by the activity of the comet, as it releases neutral particles into space where they become electrically charged due to a process called ionisation. But the precise physical mechanism behind the oscillations remains a mystery."