Big vessels, carrying robust robotic explorers and sometimes submersibles piloted by humans, embark on deep sea expeditions each year. This lightless realm remains a largely mysterious place, and just around 25% of the seafloor is decently mapped. Deep ocean missions are often considered the new exploration of little-known — or just never-visited — places on Earth.
The brittlestar Ophiocreas oedipus wrapped around coral in the deep sea.