Unknown Worlds

Behind the wheel of a Tesla Roadster, the mannequin ‘Starman’ is cruising around the cosmos, currently over a million miles from Earth. This is surely one of the craziest things to have ever been sent into space. But, publicity stunt aside, the launch on 6th February did have a serious agenda – to test SpaceX’s Falcon Heavy. The rocket was fired into low-Earth orbit with a whopping payload of 64 tonnes – the equivalent of hefting five double-decker buses into space. The endeavour has all the elements of a great adventure – vision, risk-taking and bravery to challenge science as we know it and explore new frontiers. This whole special issue is about missions, voyages and expeditions that are pushing the final frontiers and exploring unknown worlds, from the depths…

1 THE CASCADIA MARGIN The Ocean Exploration Trust recently found 500 spots off the US west coast where methane bubbles out of the seabed like champagne, and where several little-known species thrive. 2 GREENLAND In 2012, researchers stumbled across a coral reef while taking water samples 900m down off Greenland’s southern coast. Little is known about it, but similar reefs in Norway are 8,000 years old. 3 SILFRA FISSURE In the middle of Iceland, this is the only place where you can swim in the crack between two continents (the Eurasian and North American plates). It gets 2cm wider every year. 4 YUCATÁN PENINSULA Thousands of deep sinkholes form part of the longest underwater cave system in the world. The caves are flooded with freshwater overlying saltwater and many remain…

Until about a century ago, it was thought that not much lived in the deep sea. With its average depth of around 3.5km, crushing pressures and permanent darkness, few people bothered looking there – what could possibly hope to survive in such a hostile environment? According to the US National Oceanic and Atmospheric Administration (NOAA), 95 per cent of the oceans are still completely unexplored. But today’s scientists have ditched the old ideas of a deep, empty ocean and flat, featureless seabed. They’re keen to take a closer look beneath the waves and the latest generation of research equipment is opening up the depths like never before. New technology is helping scientists to understand the vital role the oceans play in the global climate and find bizarre creatures that offer…

“It feels like I’m somewhere I shouldn’t be,” says Jack Laverick, a PhD student at Oxford University, as he recalls being the first person to see part of a 100m-deep Caribbean reef. “This kind of exploration can give you tingles.” He’s one of a new breed of scientists that are venturing deeper than most scuba divers ever go. Divers can now descend into the ‘twilight zone’, from 50m down, where sunlight begins to fade. Few have visited these depths, but now so-called rebreathers are making it possible. Although invented before scuba equipment, rebreathers have only recently become safe enough for use in research. Instead of bubbling exhaled air into the water they recycle it, scrubbing out carbon dioxide and topping up the breathable oxygen. Dominic Andradi-Brown, another deep-diving PhD student from…

Tagging elephant seals on an Antarctic beach isn’t a job for the faint-hearted. Mature males weigh up to four tonnes and can easily mistake a human for another seal looking for a fight. “Elephant seals don’t have good vision,” says Dr Horst Bornemann, a researcher from Germany’s Alfred Weneger Institute for Polar and Marine Research. “You want a team who can anticipate their behaviour and fend off territorial males.” There’s a good reason for working with such colossal, bad-tempered animals in remote, sub-zero conditions, though. Southern elephant seals, the deepest-diving seal species, can dive below 2,000m for hours at a time, so fixing small, electronic sensors to their heads can transform them into a fleet of researchers. These sensors gather data on the seals’ movements – how deep they dive,…

“Very small, gentle submarines.” That’s how oceanographer Dr Pierre Testor from Paris’s Pierre and Marie Curie University describes the underwater robots he works with. In the 1980s, scientists came up with the idea of longrange vehicles that could explore hard-to-reach areas of the oceans. Today, fleets of autonomous robots, known as gliders, scour the seas for months at a time, gathering crucial data about how the oceans work. When Testor began his glider studies a decade ago, the worry of not knowing if costly equipment would make it back in one piece was tempered by the excitement of new discoveries. “I felt I was starting to do oceanography in a different way,” he recalls. Since then he’s seen gliders used in all spheres of ocean science, from physics to biology.…