A video uploaded on Youtube of footage captured by the Nautilus exploration vessel shows a patch of cobblestone pavement at the bottom of the Pacific Ocean close to Hawaii.
The murky ocean depths of our own planet also have a fair share of mysteries and strange sights that may be difficult to explain - or at least initially - while some scientists investigate the secrets of distant planets and deep space.
The crew of the Nautilus exploration vessel found one such event on the ocean fl...
