A Voyage to the Abyss
Imagine yourself slowly sinking through the shimmering blue waters of the open ocean. As you descend, the sunlight begins to fade, giving way to an eerie twilight. Welcome to the hadal zone, the deepest and darkest realms of our planet’s oceans.
More than 70% of the Earth’s surface is covered in water, yet over 80% of this vast expanse remains unexplored. In fact, we know more about the surface of Mars than we do about the seafloor that lies just miles beneath the waves. But a team of intrepid NASA scientists and oceanographers are on a mission to change that, venturing into the unknown depths in search of answers that could unlock the secrets of not only our own planet, but of worlds beyond.
As the BBC Future article explains, the hadal zone, named after Hades, the Greek god of the underworld, is a forbidding place that extends 11 kilometers (6.8 miles) below the ocean’s surface. It is a realm of crushing pressure, bone-chilling cold, and perpetual darkness – a place that until recently was thought to be devoid of life. But as these pioneering explorers are discovering, the hadal zone is teeming with a diverse array of bizarre and resilient creatures that have adapted to thrive in this alien environment.
Conquering the Crushing Depths
Leading the charge into the abyss is Tim Shank, a deep-sea biologist at the Woods Hole Oceanographic Institution (WHOI) in Massachusetts. Shank and his team are working alongside engineers from NASA’s Jet Propulsion Laboratory to develop a revolutionary new autonomous underwater vehicle (AUV) called Orpheus, which they hope will be the key to unlocking the secrets of the hadal zone.
“Orpheus is a gateway vehicle,” Shank explains. “If it works, there is no place in the ocean where you can’t go.”
The challenges facing Orpheus and its human operators are daunting. At the depths of the hadal zone, the pressure is a crushing 15,000 pounds per square inch – nearly 1,000 times the pressure at the surface. To withstand this immense force, the vehicle is constructed using a specialized syntactic foam, a buoyant material composed of microscopic glass spheres suspended in epoxy resin.
But pressure is just one of the obstacles these explorers must overcome. The waters of the hadal zone are also bitterly cold, just barely above freezing, while temperatures can soar to a scorching 698°F (370°C) in the region’s hydrothermal vents. And to make matters worse, the hadal zone is pitch black, with no sunlight to provide illumination.
As the NOAA Ocean Exploration website explains, Orpheus is equipped with a powerful LED flashlight to see in the darkness, but it must be used judiciously to conserve the vehicle’s limited battery life. The robot also carries a suite of advanced sensors and cameras, including high-definition imaging systems and tools to detect and collect environmental DNA (eDNA) – the genetic traces that organisms leave behind in the water.
Unlocking the Secrets of the Deep
For a long time, scientists believed that the hadal zone was a vast, lifeless desert, incapable of supporting any form of life. But that perception began to shift in 1977, when a team of researchers, using a remotely operated vehicle (ROV), stumbled upon a startling discovery: thriving ecosystems surrounding hydrothermal vents on the ocean floor.
“With this discovery, we came across a whole new way of living on Earth,” Shank says. “These are animals that don’t require direct sunlight; they live off chemicals coming out of the sea floor.”
The creatures that inhabit these deep-sea vents, such as translucent snailfish and tiny, shrimp-like amphipods, have evolved remarkable adaptations to survive the extreme pressures and frigid temperatures of the hadal zone. At the cellular level, they possess specialized enzymes called piezolytes that prevent their membranes and proteins from being crushed by the immense weight of the water above.
As the BBC Future article explains, these adaptations are of great interest to NASA scientists, who believe that understanding how life thrives in the hadal zone could provide crucial insights for the exploration of other ocean worlds, such as the subsurface seas of Jupiter’s moon Europa and Saturn’s moon Enceladus.
“We don’t see how we could do exploration on Europa until we did it on Earth,” Shank says. “You might also like a robot capable of exploring the Earth’s hadal zone could do the same on a frozen moon 3,904 million miles away.”
Exploring the Alien Worlds Within Our Own
To better understand the geology and chemistry of these deep-sea vents, and the unique lifeforms that call them home, NASA has launched the Systematic Underwater Biogeochemical Science and Exploration Analog (SUBSEA) program. Through a series of missions using ROVs and other underwater vehicles, the SUBSEA team is gaining invaluable insights that could inform future space exploration.
“The whole project was predicated on finding areas in our deep ocean that had a really good analogous nature to what is predicted to be active in places like Enceladus,” says Darlene Lim, a NASA geobiologist who is leading the SUBSEA program.
During these missions, the researchers have encountered a host of bizarre and captivating creatures, from the massive, shrimp-like Eurythenes atacamensis, one of the deepest-dwelling creatures known to science, to the delicate, translucent snailfish that thrive in the crushing pressures of the hadal zone.
As the NOAA Ocean Exploration news archive highlights, these discoveries are not only fascinating in their own right, but they also provide valuable clues about the potential for life in other ocean worlds. By studying how these creatures have adapted to the extreme conditions of the deep sea, scientists hope to gain insights that could guide the search for extraterrestrial life.
Lessons for the Final Frontier
But the lessons learned from exploring the hadal zone go beyond just the search for alien life. Shank and his team at WHOI are also working to develop new technologies and techniques that could have far-reaching implications for the future of space exploration.
One key area of focus is the development of autonomous robotic systems that can operate in the deep ocean without the need for constant human supervision. As the NOAA Ocean Exploration website explains, Orpheus and other AUVs are designed to be highly independent, able to make decisions and navigate the seafloor using advanced computer vision and mapping algorithms.
This same technology is being adapted for use on future space missions, where the vast distances and communication delays make it impossible for human operators to directly control robotic explorers. For example, NASA’s Volatiles Investigating Polar Exploration Rover (VIPER), which is set to launch in 2023, will use many of the same autonomous navigation and decision-making capabilities as the deep-sea AUVs.
“Everything we learned by working together with the oceanographic community has been completely invaluable, really priceless in helping us have confidence in the process that we’re using to design our science operations for VIPER,” says Lim, the NASA geobiologist.
Charting the Unknown
But the benefits of this deep-ocean exploration go beyond just space exploration. As IT Fix explains, the technologies and techniques developed for probing the hadal zone could also have far-reaching implications for our understanding and stewardship of our own planet.
“We need to understand our oceanic environments if we are to save them,” says Laura Lorenzoni, ocean biology and biogeochemistry program scientist with NASA’s science mission directorate. “This is critical for life on Earth, and the sustained measurements NASA has done and continues to do are fundamental for ensuring a sustainable use of our ocean resources.”
From mapping the seafloor and monitoring ocean currents to studying the impacts of climate change on marine ecosystems, the data and insights gleaned from these deep-sea expeditions could prove invaluable in the fight to protect our blue planet.
As Shank and his team prepare to send Orpheus on its maiden voyage into the abyss, the sense of excitement and wonder is palpable. “If it works, there is no place in the ocean where you can’t go,” he says, his voice tinged with a hint of awe.
It is a sentiment that captures the true spirit of exploration – the drive to push the boundaries of human knowledge and understanding, to venture into the unknown and uncover the secrets that lie hidden in the depths. And with the help of cutting-edge robotic explorers like Orpheus, the future of ocean discovery has never looked brighter.
So, who knows what wonders may await us in the inky blackness of the hadal zone? Only time, and a few intrepid robots, will tell.
