By Ella Prendergast
A mysterious Star Wars-like noise picked up from the world's deepest ocean has baffled scientists.
The deep, echoey noises were recorded in the Mariana Trench - located between Australia and Japan - over two years by researchers at Oregon State University.
The sound reaches extreme high and low frequencies within 3.5-seconds.
More than 400 calls were heard from the trench, which reaches depths of over 10,000 metres.
So far scientists can't identify the noise, but do have a few potential leads.
"It's very distinct, with all these crazy parts," said Sharon Nieukirk, senior faculty research assistant in marine bioacoustics at Oregon State. "The low-frequency moaning part is typical of baleen whales, and it's that kind of twangy sound that makes it really unique. We don't find many new baleen whale calls."
Researchers said the sound resembles the so-called "Star Wars" sounds produced by the dwarf minke whale, a type of baleen whale found near Australia.
But many other questions remain unanswered.
"If it's a mating call, why are we getting it year round? That's a mystery," said Ms Nieukirk.
"We hope researchers can identify this call in past and future data, and ultimately we should be able to pin down the source of the sound," she said.
"It really is an amazing, weird sound, and good science will explain it."