Earthlings have just landed the Philae space probe on a comet -- a universe first. But there's no rest for the wicked -- Philae is already hard at work investigating it with the
instruments on board. Following the landing, one of the first things researchers have discovered about comets is that they actually emit their own orbital ditties and "sing into space".
But what do they mean by "singing?" What researchers have found out is that the comet belts out its tunes in the form of "oscillations in the magnetic field of the comet's environment".
And according to a blog post from the European Space Agency, this song is being sung at "40-50 millihertz", which incidentally, is too low for regular humans to hear. The human ear only picks up sound between 20Hz and 20kHz.
And how exactly does it detect this "music"? The five instruments aboard the Rosetta Plasma Consortium (RPC) are able to provide information on the plasma environment, surrounding the comet. Just as a reminder, plasma is an ionised state of matter, which carries electrical currents and magnetic fields.
The instruments share the same electrical and data interface with the Rosetta orbiter. They are designed in such a way that they can study the continuous stream of plasma emitted by the Sun, changes of activity on the comet itself, as well as the interaction of 67P/C-G with solar wind -- to name but a few things.
At the moment, the exact physical mechanisms behind these spacial oscillations, remains an enigma. Yet researchers are speculating that they may be produced by the comet's activity, "as it releases neutral particles into space", transforming into electrically charged particles due to an "ionisation process".
In order for humans to hear the comet's music, the frequencies must be increased by a factor of 10,000. Further sonification was undertaken by German composer Manuel Senfft to transform the comet's spacial melody into something people on Earth could relate to.
This recent sonic contribution by 67P/C-G adds to a symphony of other space recordings such as the radio waves that Nasa's Cassini spacecraft picked up in January 2001 near Jupiter, ghostly planetary plasma waves collected by Nasa's Voyager 2, and bizarre space "whistles".
This article was originally published by WIRED UK
