A noisy Universe!

Above: The Parkes Radio Telescope at dusk...

The vast majority of the Universe is vacuum, so it should be utterly, utterly, silent.  Yet, paradoxically, it has turned out to be an incredibly noisy place. And I'm not talking about the unbelievable volume a hungry 6 month old can produce at 3am. The  universe is filled with electromagnetic signals - and, we now know, gravitational signals.
Some of it is a bit more structured than just white noise - sometimes with an eerie beauty. My favourite is Neptune, which makes  noise that somehow reminds me of a choppy ocean... 

 

Other objects in the universe make stranger 'sounds': The comet 67-P that the Rosetta spacecraft explored gives of magnetic oscillations that translate into a sound like this:

Pulsars - rapidly spinning neutron stars that give out beams of intense radiation - give out a radio noise like someone knocking on a wooden table....

And, with the advent of gravitational wave detection, we can listen in on the gravitational wave 'noise' of gigantic black holes colliding.....

 

 

Some signals are simply unknowns - one such are the 'fast radio bursts', which are still baffling radio astronomers, and don't seem related to any astrophysical phenomena:

 

 

So, it's less a 'silent night' out there, more 'sky shouting at us'. If you'd like a truly unique musical experiance, run your audio through a decent pair of speakeres, then loop all the above soundtracks, and play them together in a dim room.
And, just in case you don't believe me that the sky is singing to you, here's how to pick them up yourself....