Our oceans occupy more than 70% of the Earth’s surface, but more than 78% of them remain unknown.
Indeed, it is sometimes asserted that scientists know more about the surfaces of Mars and the Moon than we do about the ocean floor on Earth.
Nasa is working hard to fix that. The US space agency is studying the deep ocean in search of hints about what oceans on other worlds could look like, as well
as pushing the boundaries of science and technology in one of our planet’s most harsh settings.
It’s a mission full of awe, peril, and the not-insignificant threat of collapse.
The objective is that the undersea discoveries they make will aid in the discovery of some of the secrets of space while also testing some of the equipment and
experiments required for trips outside in the Solar System.
The depths of Earth’s oceans are remarkably comparable to some of the conditions Nasa expects to discover on other worlds in our Solar System.
They may also give hints as to where scientists should look for alien life.
The hadal zone refers to the deepest sections of the Earth’s seas. It is a foreboding site befitting of its name, named after Hades, the Greek deity of the
underworld. It spans 11km (6.8 miles) below the surface of the world’s seas and is made up of deep trenches and troughs. They account for an area of seafloor similar to
the size of Australia when added together. Few cars, however, can survive the plunge into this black pi.
Nasa scientists are aiming to study and test the boundaries of life on Earth here, in collaboration with the Woods Hole Oceanographic Institute (WHOI)
Even the vocabulary used by scientists on trips to this region contains phrases from space exploration in recent years, marine biologists have dispatched
numerous “landers” equipped with sensors and cameras to “crashland” on the hadal zone’s floor, where they gather measurements.
Scientists at NASA’s Jet Propulsion Laboratory in Southern California, however, are developing Orpheus, named after the ancient Greek hero who travelled
to the underworld and back, to survey the more difficult depths.
Orpheus employs very sensitive cameras to recognise rock formations, shells, and other things on the ocean floor to construct threedimensional maps
marked with markers, similar to Nasa’s Perseverance Mars Rover (or perhaps seabedmarks).
This not only helps the robot to navigate and identify sites it has already been, but it should also help it shed fresh light on the biodiversity of this
The scientists uncovered thriving ecosystems filled with marine species such as transparent snailfish and amphipods, small flealike crustaceans that
had never been observed before.
“With this finding, we found an entirely new way of existing on Earth,” Shank adds. “These are critters that don’t need direct sunshine… they survive off
chemicals that come up from the sea floor.”
The experts were baffled: how could organisms in the hadal zone withstand such crushing pressure?”There’s 15,000 pounds per square inch of pressure,
” Shank explains. “It’s so powerful that an animal’s individual cells would be pushed out.
“Discovering creatures that can not only survive, but flourish in such a harsh environment raises fundamental concerns for scientists looking beyond our
own planet might it be found on other ocean worlds?
A robot capable of researching the Earth’s hadal zone might do the same on a frozen moon 628.3 million kilometres (390.4 million miles) distant.
“The ocean floor is a perfect testing ground for us to develop the technology that we need to make a successful voyage to one of these underwater planets,
” says Russell Smith, an engineer from Nasa’s Jet Propulsion Laboratory who is part of the team creating Orpheus.
A robot working in outer space or the deep ocean, on the other hand, must be entirely independent.
“The robot has to be able to make judgments,” Smith explains, adding that the goal is for Orpheus to identify and analyse environmental DNA and substances
in the water, as well as bring back data from the ocean bottom.
Building a robot for the hadal zone, he claims, is extremely difficult.
While launching robots to Europa and Enceladus may be decades away, Nasa scientists are already using what they’ve learnt from deep sea exploration to
Nasa will send a robotic rover to our Moon’s south pole in 2023 to seek for water ice. The Volatiles Investigating Polar Research Rover, or Viper, will explore
ice near the lunar crater Nobile in the hope that it may be mined for rocket fuel or drinking water. A rover on the Moon, while not operating underwater,
will confront many of the same technical problems.
“We’re taking what we learned from Subsea and applying it to Viper,” adds Lim, who is also the Viper’s deputy lead project scientist.
It indicates that with each step towards the investigation of other worlds, we learn a little bit more about some of our own blue planet’s most undiscovered