Watch creatures of the abyss in Earth's deepest ocean trench

The expedition has only just begun and already it is producing some stunning footage of the denizens of Earth's deepest abyss. NOAA's Okeanos research ship will spend the next two months cruising the seas above the Mariana trench, using sonar systems and a remotely operated vehicle (ROV) to explore the little known parts of the trench and its surroundings. Footage from the daily dives is being live-streamed, with highlights posted on the expedition site. On 24 April the ROV captured this footage of a beautiful jellyfish (see video above), belonging to the Crossota genus, at a depth of nearly 4 kilometres. On 25 April it filmed a striking, violet sea cucumber swimming above the sea floor (see video below).