By Frankie Pavia
How far is five kilometers, vertically? We leaned over the edge of the boat, staring into the water, watching the last glimmer of light from the in-situ pump disappear into the abyss. The furthest down we could see the pump was 50 meters from the surface—remarkably far to still see light anywhere in the ocean, courtesy of the life-devoid upper waters of the South Pacific.
That’s a comprehensible depth, 50 meters. It’s about the same as a 15-story building. But five kilometers? My German colleague and I could conceptualize five kilometers horizontally—the same as her bike ride to work, the same as the first ever race I ran. Neither of us could quite grasp what flipping 5 kilometers 90 degrees might mean, as our pump continued on its 3-hour vertical journey to that depth.
The spirit of exploration is embedded within all scientific research. It is a quest to probe and understand the unknown. But oceanographers and astronauts have something more than that—the work they do also involves the physical exploration of spaces that have yet to come under dominion of humanity. The ocean and space have not yet been rendered permanently habitable. No human lives at sea or in space without having to depend on land for survival.
I expected to conclude the cruise with a deeper connection to the ocean. I expected to feel like I had performed an act of exploration by sailing from one land mass to another, and as a result to have gained some fundamental understanding of the ocean’s spatial domain.
Yet a week after I stepped foot from the FS Sonne for good, I am left feeling like the ocean is further from my grasp than ever. Five kilometers depth, and all I did was sail across a tiny fraction of the surface. Sure, I hauled back samples from the deep, and I will certainly learn an incredible amount about it from chemical measurements. But did I explore the deep ocean? Is it possible to explore a place without actually traveling there?
I wonder how astronauts feel when they return to Earth. Just like oceanographers experience only the top of the ocean, astronauts only scratch the surface of an incomprehensibly large volume of space. Does it make them feel like a part of something greater, or does experiencing its massive scale make them feel even smaller?
While the ocean is a vast nexus of life, space is seemingly devoid of it. The ocean certainly holds clues as to how life formed on our planet, and where it may exist on distant moons in our solar system. On Mars, it is the locations of long-dessicated oceans and running water where life is thought to have been possible in the distant past. In habitability, oceans are our pluperfect, Earth is our future perfect, space is our future.
The connection between oceans and space will certainly be a source of excitement for science in the coming years. Ice-covered moons in our solar system have liquid water oceans; surely there are planets and moons orbiting stars other than ours that have them as well. How will we ever understand them if we have only seen such a small portion of the ocean’s volume on Earth?
And so we plunge onward into the indomitable vastness of the oceans, of space. I came away feeling further than ever from the oceans after this cruise. To fix that, I must keep exploring.
Frankie Pavia is a second-year graduate student studying oceanography and geochemistry at Lamont-Doherty Earth Observatory.
