Here's something you don't hear every day: The sound of a comet whizzing through outer space.
The Rosetta spacecraft has captured the sound emitted by Comet 67P/Churyumov-Gerasimenko, which is produced by "oscillations in the magnetic field in the comet's environment." Space.com says that it's such a faint noise that the European Space Agency had to increase the frequency of the sound by about 10,000 times its actual rate so it could be heard.
ESA scientists say this could be caused by neutral particles of the comet becoming electrically charged through ionization, but they're not entirely sure. "This is exciting because it is completely new to us," Karl-Heinz Glaßmeier, head of Space Physics and Space Sensorics at the Technische Universität in Germany, said in a statement. "We did not expect this and we are still working to understand the physics of what is happening." --Catherine Garcia