Dictionary.com defines alien in the broadest sense as “unlike one’s own; strange; not belonging to one.” In this way so many creatures are alien to us, especially those of the sea; sea monsters are as alluring today as they were in the times when marine maps featured many-headed serpents, even if the monsters (and we) have changed. Today humankind dives deeper into the ocean than ever before, literally and figuratively.
The ocean is home to what seem to us extreme lifeforms. A few of my personal favorites are the hammerhead shark, with it’s oddly elongated head and inherent sharkiness (sharks are deeply embedded as alienesque in the human psyche); anglerfish, which live in the dark depths and look like something out of a sci-fi horror film; and octopuses (no, it’s not octopi; thank you The Soul of an Octopus) which have an odd nervous system consisting of multiple brains and are known to break into other tanks in aquariums.
There are even microscopic creatures living at hydrothermal vents where they experience incredibly hot temperatures and extremes of chemical environment that we humans would never survive. And let’s not forget jellyfish, which I always thought looked edible – and many, in fact, are.
But what do the finite depths of the ocean down there have to do with the vast expanse of space up there?
For one thing, oceans like ours exist on other bodies in our very own solar system (Neptune’s moon Triton, for the perfect example). If there’s life in ours, why not in others?
For another, discovery of “extreme” lifeforms here on Earth allows for the possibility of other, different “extreme” lifeforms elsewhere. Imagine: creatures that breathe molecules rather than oxygen; beings with nervous systems that allow perceptions we can’t even imagine; lifeforms able to swing from survival at subzero to survival above 120°F. All of these and more could possibly exist. There is already evidence that we understand a lot less about life than we think we do, so why not? Life might survive where we never expected it to.
But it’s not just about survival. If life never emerges, it can’t endure. Is the emergence of life fundamental in a complex system? That’s a big – no, monumental – question. And certainly not one currently answerable. But considerations like this – complexity, emergence, possibilities, astrobiology – excite me and I will continue to explore them. ✿