Challenger Deep is the deepest, darkest part of the earth's sufrace, 11 kilometres below the surface of the Pacific Ocean - and for the first time ever, scientists have managed to record what it sounds like.
The spot is a relatively small depression within the Mariana Trench, off the coast of the Mariana Islands and Guam.
Oceanographer Bob Dziak of the National Oceanic and Atmospheric Administration (NOAA) told Gizmodo that like much of the sea bed, little is known about it - and since sunlight doesn't penetrate that far down, it's easier to use sound waves to build up a picture of what life might exist at the deepest known point on earth.
Rattails, decapods, supergiants and snailfish at 7km deep inside the Mariana Trench (Still via OceanLab, University of Aberdeen)
Dziak's team designed and sent a titanium-encased recording instrument capable of acclimatising to the ocean's intense pressure levels called a hydrophone to the bottom of Challenger Deep.
It spent 23 days at the bottom of the trench, and then NOAA had to wait until November for good enough weather and a gap in shipping traffic to carefully bring it back up.
The team found out that Challenger Deep acts like an 'echo chamber' for noises passing above, including whales, ships, and even the sounds of a category four typhoon on the ocean surface.
Anyway. You can listen to a few of the the eerie, alien rumblings below: