Originally reported by The Sun, Researches picked up an alien sound while their hydrophone was over the Mariana Trench.  Although whale like in nature, it does not quite fit the patterns of what researchers already know. To listen to this sound,  Click here.  Initially, they thought it might be a mating call from whales, but they are thrown off by hearing this sound year round.

There was a follow-up piece on Wired,

The mystery of the ‘alien call’ deep in the Mariana Trench is solved

which seems to indicate it is a Baleen Whale…. but the article does end with… “more data needed….. ”

It does make for good Sci-Fi, especially now that I have been working on a treatment called HUM, which is about an alien life-form that was attracted to Earth by its sound.   Yes, yes, I know… sound does not travel through space… but other signals do and who is to say what wavelengths aliens can hear.