Picture a single point in the South Pacific, halfway between the Chatham Islands of New Zealand and southern Chile, where the water runs more than 4,000 metres deep and the nearest coastline lies a continent’s width away. There is nothing to mark it. No buoy, no island.

The spot sits at 48°52.6′S 123°23.6′W, and sometimes the closest human beings to it are not standing on any shore. When the International Space Station passes overhead, they may be roughly 400 kilometers straight up.

A point with no address

This is Point Nemo, the oceanic pole of inaccessibility. It wasn’t discovered by an expedition — it was calculated. In 1992, Croatian-Canadian survey engineer Hrvoje Lukatela used geospatial software that modelled the curvature of the Earth to find the single coordinate at maximum distance from every coastline. The result was a point so remote that Lukatela borrowed a name from fiction for it: Captain Nemo, the submarine recluse of Jules Verne’s novel, whose Latin name simply means “no one”.

Almost no one lives anywhere near it. The surrounding stretch of ocean, part of the South Pacific Gyre, is one of the least biologically active patches of sea on the planet. In a 2019 study, researchers from the Max Planck Institute for Marine Microbiology who had sampled microbes across the South Pacific Gyre — the broader stretch of ocean Point Nemo sits within — reported probably the “lowest cell numbers ever measured in oceanic surface waters”. Even the microscopic life thins out here.

The geometry of nowhere

The pole of inaccessibility sits roughly equidistant from its three nearest scraps of land, each lying about 2,688 km (1,670 miles) away. To the north is Ducie Island, an atoll in the Pitcairn group. To the northeast is Motu Nui, a small islet off Rapa Nui, better known as Easter Island. To the south, off the Antarctic coast, sits Maher Island. 

The nearest people on land are well over two and a half thousand kilometres away in any direction, and the land near those three vertices has no permanent residents. To reach an actual town or city from Point Nemo, you would have to travel thousands of kilometres.

The astronaut paradox

The International Space Station orbits at an altitude of about 400 km (250 miles). When its ground track carries it over the South Pacific, the astronauts aboard are closer to Point Nemo than any human being on the planet’s surface. The 400 kilometres of vertical distance to orbit is a fraction of the 2,688 kilometres to the nearest uninhabited island, never mind the far greater distance to anyone who actually lives somewhere.

At Point Nemo, up is nearer than across. The emptiest spot on the ocean surface is regularly visited, in the loose sense of proximity, by the only humans who happen to be passing overhead at the right moment.

What gets sent there

That same emptiness has given Point Nemo a second identity. The region around it, formally the South Pacific Ocean Uninhabited Area and informally the spacecraft cemetery, has been used for controlled spacecraft disposal since 1971. According to figures compiled by the space-debris community, more than 260 spacecraft were brought down in the region since 1971. 

The logic behind the choice is straightforward. Stijn Lemmens, a space debris analyst at the European Space Agency, has described the site-selection process as a search to “look around the world for where nobody is living, where nobody is flying and where you have no boats”. There are a handful of places on Earth that fit. As Lemmens puts it, “Point Nemo is one of them.” It offers what he calls the “widest possible area” to land spacecraft safely.

The most consequential delivery may still be coming. The ISS, at roughly 420 tonnes, is expected to be guided into the wider South Pacific Ocean Uninhabited Area around Point Nemo at the end of its operational life, making it the largest human-made structure ever deliberately brought down from orbit.

The most isolated coordinate in the ocean is empty of people but no longer free of their leavings.