Rosetta's comet emits a mysterious 'song'

Scientists trying to land a probe from the Rosetta spacecraft today have noticed that its target comet appears to be singing.

The Rosetta mission carries several instruments that are designed to measure conditions on the 67/P Churyumov-Gerasimenko surface, and one recently picked up a mysterious signal.

The frequency of the sound is between 40-50 millihertz, which is too low for the human ear to pick up directly, but the recording has been amplified around 10,000 times to make it audible.

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