Scientists finally solve mystery of 'alien' noises coming from deepest part of Pacific Ocean

The Mariana Trench is one of the most mysterious places on Earth. So it's no surprise that unusual sounds coming from the Mariana Trench sparked fears of an alien invasion when they were first recorded back in 2014. Measuring almost seven miles deep, the Mariana Trench sits on the floor of the Pacific Ocean and is so difficult to reach that just a handful of people have ventured down there The eerie noises were first recorded in 2014 by underwater gliders, which were being used to carry out acoustic surveys of the trench. Lasting between 2.5 and 3.5 seconds, the five-part sounds included deep moans at frequencies as low as 38 hertz and a finale that pushed as high as 8,000 hertz Rather than being produced by baleen whales, the new study suggests that Bryde's whales are responsible. Bryde's whales can be found around the world in warm, temperate oceans including the Atlantic, Indian, and Pacific The unusual sounds coming from the Mariana Trench sparked fears of an alien invasion when they were first recorded back in 2014 The researchers spotted ten of the whales swimming in the area, and even recorded nine making the distinctive noises.