We have spent more time exploring the surface of the moon than we have the floor of the ocean. The ocean’s floor is just as hostile as the moon’s surface. There are some key differences between the two, of course. For one, there is more light on the moon. The sun lights a barren landscape on Luna, but it lights nothing on the bottom of the ocean.
Perhaps it is best that the sea gets darker as we descend into its depths, because the creatures get scarier. The euphotic zone extends from the surface to about 650 feet. This zone is home to most of the sea life we are used to, such as tuna, dolphins and pretty coral fish. Next comes the dysphotic zone, which reaches down to 3,200 feet and gets dark rapidly with depth. The life here is strange. Such creatures as dragonfish, snipe eel, medusas and coelacanths, which were once thought to be extinct, help to paint a picture of life at this level.
This brings us down to about 3,200 feet, but the average depth of the ocean is 14,000 feet. Does life get even stranger as we approach this depth? From what we have seen, it certainly does. There is no sunlight at this depth, and from here to the lowest known point of the ocean, the 36,070 foot Challenger Deep, it gets stranger. Angler fish attract prey with a luminescent “worm” that sticks out of its head. When its prey comes close to investigate, the angler fish lunges forward and impales the prey on its pointy teeth before swallowing it whole. Giant squid and enormous sperm whale fight to the death, as evidenced by deeply scarred whales that occasionally wash up on shore.
Most people will go no further than 15 feet below the surface of the ocean in their lives. This is barely a scratch on the surface of the amazing depths that hide mountain ranges higher than the Himalayas and life stranger and scarier than anything that may exist in other solar systems.