‘Dark Oxygen’ mission takes aim at other worlds

Scientists who recently discovered that lumps of metal on the deep sea floor create oxygen have announced plans to study the deepest parts of Earth’s oceans to understand this strange phenomenon.

The researchers say their mission “could also change the way we look at the possibility of life on other planets.”

The initial discovery puzzled marine scientists. It was previously accepted that oxygen could only be produced by plants in sunlight – in a process called photosynthesis.

If oxygen – a vital component of life – is created by clumps of metal in the dark, researchers believe the process could occur on other planets, creating oxygen-rich environments where life could thrive.

“We are already in talks with NASA experts who believe that dark oxygen could reshape our understanding of how life can survive on other planets without direct sunlight,” said lead researcher Professor Andrew Sweetman. Could stay.

“We want to go in there and find out what’s really going on.”

The initial discovery created a global scientific controversy – there was Criticism of the findings Some from scientists and deep-sea mining companies who plan to harvest precious metals in ocean bodies.

If oxygen is produced at these extreme depths, in complete darkness, it raises questions about what life can survive and thrive on the ocean floor, and what impact mining activities might have on that marine life. .

This means that seabed mining companies and environmental organizations – some of which claimed the findings provide evidence that seabed mining plans should be halted – will be keeping a close eye on this new investigation.

The plan is to work in locations where the ocean floor is deeper than 10 km (6.2 mi), using remotely operated submersible equipment.

“We have instruments that can reach the deepest parts of the ocean,” Professor Sweetman said. “We are confident that we will find this occurring elsewhere as well, so we will begin to investigate what is causing it.”

Some of those experiments, in collaboration with NASA scientists, will aim to understand whether the same process could allow microbial life to flourish beneath the oceans on other planets and moons.

“If there’s oxygen there, there could be microbial life taking advantage of it,” Professor Sweetman said.

Preliminary, biologically surprising findings were published last year In the journal Nature GeoscienceThey came from several expeditions to an area of ​​the deep sea between Hawaii and Mexico, where Professor Sweetman and his colleagues sent sensors to a depth of about 5 km (3.1 mi) on the ocean floor.

That area is part of a vast swath of ocean floor covered with naturally occurring metal nodules, which form when metals dissolved in seawater collect on oyster fragments – or other debris. This is a process that takes millions of years.

The sensors deployed by the team repeatedly showed increasing oxygen levels.

“I ignored it,” Professor Sweetman told BBC News at the time, “because I was taught you only get oxygen through photosynthesis”.

Eventually, he and his colleagues stopped ignoring their readings and instead set out to understand what was going on. Experiments in their laboratory – with nodules that the team collected while submerged in beakers of seawater – led scientists to the conclusion that the metal nodules were creating oxygen from seawater. They found that the nodules generate electrical currents that can split (or electrolyze) seawater molecules into hydrogen and oxygen.

This was followed by a response from scientists and marine mining companies in the form of rebuttals posted online.

One of the critics, Michael Clarke of the Canadian deep-sea mining company Metals Company, told BBC News that the criticism focused on “the lack of scientific rigor in experimental design and data collection”. Originally, he and other critics claimed that no oxygen production occurred – only bubbles came out of the instrument during sample collection.

Professor Sweetman responded, “We have ruled out that possibility.” “But these (new) experiments will provide evidence.”

This may seem like a specific, technical argument, but multi-billion pound mining companies are already exploring the possibility of harvesting tons of these metals from the seabed.

The natural reserves they are targeting contain metals important for making batteries, and demand for those metals is growing rapidly as many economies move away from fossil fuels toward, for example, electric vehicles.

The race to extract those resources has raised concerns among environmental groups and researchers. There are more than 900 marine scientists from 44 countries signed a petition Highlighting environmental risks and calling for a moratorium on mining activity.

Speaking about his team’s latest research mission at a press conference on Friday, Professor Sweetman said: “Before doing anything, we need to understand – as best we can – the (deep sea) ecosystem.

“I think the right decision is to stop this before we decide whether it’s the right thing to do as a global society.”