Comet’s haunting ‘song’ captured
In the build-up to the landing of the Philae probe on comet 67P/C-G on Tuesday, scientists learned something surprising.
The comet makes a noise - now being called a “song”.
The European Space Agency successfully landed the probe after 10 years of work, even though harpoons designed to anchor it failed to deploy, Reuters reports.
In the build-up to the landing, the news of the comet’s song was broken.
In a press statement carried on the Rosetta blog, Karl-Heinz Glaßmeier, head of Space Physics and Space Sensorics at the Technische Universität Braunschweig, Germany, said the comet seemed 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,” he said.
Glaßmeier is principal investigator for Rosetta’s Plasma Consortium (RPC).
“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,” he said.
He said the song observation had “taken the RPC scientists somewhat by surprise”.
The music was heard clearly by the magnetometer experiment (RPC-Mag) for the first time in August, when Rosetta drew to within 100km 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.
“This is exciting because it is completely new to us. We did not expect this and we are still working to understand the physics of what is happening.”IOL