Les scientifiques ont récemment fait une découverte surprenante : une forme mystérieuse d'oxygène, qu'ils appellent l'oxygène "sombre", trouvée ici même sur Terre. Contrairement à l'oxygène que nous respirons, ce type ne se comporte pas comme les scientifiques l'avaient prévu, ce qui le rend plus difficile à détecter. On pense qu'il existe dans des conditions extrêmes, comme en profondeur sous terre ou dans des endroits soumis à une pression intense. Cette nouvelle découverte pourrait nous aider à mieux comprendre les couches profondes de la Terre et comment les éléments se comportent dans de tels environnements sévères. Certains pensent même qu'elle pourrait révéler de nouvelles pistes sur le comportement de l'oxygène sur d'autres planètes. C'est un rappel fascinant qu'il y a encore tant de choses que nous ignorons sur notre propre planète ! Animation créée par Sympa. ---------------------------------------------------------------------------------------- Musique par Epidemic Sound https://www.epidemicsound.com Pour ne rien perdre de Sympa, abonnez-vous!: https://goo.gl/6E4Xna ---------------------------------------------------------------------------------------- Nos réseaux sociaux : Facebook: https://www.facebook.com/sympasympacom/ Instagram: https://www.instagram.com/sympa.officiel/ Stock de fichiers (photos, vidéos et autres): https://www.depositphotos.com https://www.shutterstock.com https://www.eastnews.ru ---------------------------------------------------------------------------------------- Si tu en veux encore plus, fais un tour ici: http://sympa-sympa.com
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00:00When we venture into the glacial depths of the Pacific at 4,000 meters below the surface, a strange phenomenon occurs.
00:08Oxygen levels rise abruptly.
00:10This makes no sense because we are then plunged into a terrifying darkness.
00:15It was then that the researchers realized that they were confronted with a totally unprecedented discovery, dark oxygen.
00:22This particular type of oxygen, which forms in the cold abysses of the ocean,
00:27could shake our understanding of the origins of life on Earth.
00:30It could even bring us closer to the possibility of discovering life on distant planets.
00:35And this discovery was made by sheer chance.
00:38Our exploration begins in the Clarion-Clipperton area,
00:42a vast region of the Pacific that extends over a surface larger than that of Mexico.
00:46Reaching the depths of this place, we come across strange piles of the size of potatoes, scattered on the seabed.
00:54These formations are officially designated as polymetallic nodules.
00:58Although they may seem insignificant at first glance, these small structures actually contain hidden treasures.
01:06Over millions of years, metals dissolved in seawater slowly accumulate around tiny fragments of shells or debris,
01:13giving birth to these nodules.
01:14Inside, we find precious metals such as manganese, nickel, copper and cobalt,
01:21essential for the manufacture of the batteries of our mobile phones and electric vehicles.
01:26This is why the Clipperton fracture zone has become a high point of underwater mining.
01:32To date, 16 companies specializing in the exploitation of large funds
01:36have obtained permission to explore about 20% of its underwater surface.
01:41This rumble towards the depths aroused the curiosity of the researchers,
01:45eager to unravel the mysteries of the abyss.
01:48They therefore deployed the means to collect samples of sediment.
01:52And it was at this moment that things took a strange turn.
01:55The instruments began to reveal something unimaginable.
01:58Significant amounts of oxygen produced on the seabed, in total and absolute darkness.
02:04Wait a minute, this shouldn't happen.
02:08The more we go down into the ocean, the less oxygen we find in the water.
02:11At about 900 meters deep, there is almost no oxygen left,
02:15because the water is too far from the surface to allow any exchange with the atmosphere.
02:19To complicate things, oxygen is continuously consumed by living organisms in the deep,
02:25as well as by bacteria that decompose organic matter.
02:28Thus, the production of oxygen at this depth is supposed to be impossible.
02:33At first, the researchers did not believe it.
02:36They assumed that the sensors were defective.
02:39Because all the studies carried out in the marine depths
02:42had shown that oxygen consumption was never its production.
02:46However, the same results kept coming back.
02:49For 10 years, this mysterious oxygen continued to appear.
02:53They eventually came to the conclusion that their data could be correct.
02:58It turns out that these metallic nodules could actually generate oxygen by acting like batteries.
03:03When you immerse a battery in seawater,
03:06you can observe bubbles and hear a crackling,
03:09because the electric current decomposes seawater into oxygen and hydrogen,
03:13in a process called electrolysis.
03:16Thus, the theory advanced by the researchers suggested that these nodules
03:20performed the same function, but in the natural state.
03:23And they were right.
03:25The nodules were indeed charged electrically,
03:28with a voltage of about 0.95 volts.
03:31This level of energy is insufficient to dissociate seawater into hydrogen and oxygen.
03:36It would take about 1.5 volts,
03:39or the power of a AA battery.
03:41However, when these nodules regroup,
03:44much higher tensions can be observed,
03:47enough to trigger the reaction and produce oxygen.
03:50Thus, these nodules were able to generate electric currents
03:55powerful enough to decompose seawater molecules
03:58and produce oxygen,
04:00even in the total absence of light.
04:02This discovery is fascinating,
04:04because it questions our understanding of the production of oxygen.
04:08Until now, we had always believed that oxygen was generated by photosynthesis,
04:13this process by which plants and algae transform sunlight into energy
04:18and release oxygen.
04:20But in this totally dark marine environment,
04:23oxygen was produced only by electrolysis.
04:26No sunlight was necessary.
04:28This is why we began to call it dark oxygen.
04:32This discovery encourages us to reconsider how life could have emerged on Earth
04:37more than 3 billion years ago.
04:39Think about it.
04:40Plants need oxygen to live,
04:43but they are also the producers of it.
04:45So where did the first oxygen come from?
04:49This complex dilemma is like the puzzle of the hen and the egg.
04:53But it could be that there is now an answer,
04:56knowing that oxygen can be produced without using sunlight or photosynthesis.
05:02It is conceivable that a mysterious source of oxygen existed at that time,
05:06thus allowing breathing life forms to evolve
05:10even before photosynthesis was established.
05:13Dark oxygen does not only modify our understanding of the terrestrial past,
05:17but it also opens up new perspectives on life elsewhere in the universe.
05:22If this phenomenon occurs on our planet,
05:24it is plausible that it also occurs on other celestial bodies.
05:28Let's take as an example the moon Enceladus of Saturn
05:31and the moon Europe of Jupiter.
05:34Both seem to shelter liquid and saline oceans,
05:37concealed under thick layers of ice.
05:40Could dark oxygen also generate environments rich in oxygen in these oceans?
05:45The repercussions of this discovery go far beyond our solar system.
05:50It pushes us to reconsider the way we define habitats suitable for life.
05:55In our explorations of exoplanets orbiting distant stars,
05:59understanding the production of oxygen in the dark
06:02could help us locate places where life could exist
06:05in very different conditions from those on Earth.
06:08Instead of limiting ourselves to the search for planets bathed in sunlight,
06:12scientists could have to explore signs of chemical reactions
06:16likely to promote life even in total darkness.
06:20These news are exciting,
06:22but let's not forget the starting point of our story.
06:25High-sea mining.
06:28This is how this process usually takes place.
06:31Companies deploy a remote-controlled submarine vehicle,
06:35similar to a tractor, to move along the ocean floor.
06:39This vehicle collects the metallic nodules and sediments,
06:43then sucks them through a pipe to a surface vessel.
06:47Once the nodules are collected,
06:49the crew sends the residual sediment into the ocean at an intermediate depth,
06:53where it ends up being deposited again on the seabed.
06:56So, is mining in deep water beneficial or harmful?
07:01It's hard to tell.
07:03On the one hand, we have discovered a massive and promising metal deposit
07:07essential to the manufacture of new ecological technologies
07:11such as solar panels and electric vehicles.
07:14With a demand for these critical materials,
07:16which could rise to 600% in the next decades,
07:20mining in the high seas could prove to be decisive.
07:24Some research even suggests that this activity could be less harmful
07:29than conventional mining.
07:31As it takes place far from the coast,
07:34it could help preserve forests and avoid pollution from fresh water sources.
07:39In addition, the fact that these minerals are difficult to access
07:42could facilitate the monitoring of this activity,
07:45thus allowing to maintain control and regulate the process.
07:49However, there is also a growing concern
07:52that the search for precious minerals in the ocean
07:56could disrupt the production process of this dark oxygen.
07:59These metal-rich nodules are not just inactive,
08:03they play a role in the chemical processes that influence our planet.
08:07Indeed, they could be essential to many things,
08:10from nutrient cycles to the emergence of new forms of life.
08:13Scientists therefore fear that mining
08:16will damage marine life and habitats that depend on dark oxygen.
08:21Despite its isolated location and its extreme conditions,
08:24the Clareon-Clipperton area houses an amazingly varied and mysterious range
08:29of large-bottom creatures,
08:31ranging from sea anemones to spectral whites,
08:33and sea cucumbers from a deep violet to small marine isopods,
08:37cousins far from the Cloportes.
08:40However, our knowledge of these inhabitants of the depths remains limited.
08:44It is estimated that 90% of the species living in the deep waters of this area
08:49are still unknown to science.
08:51We know that they exist, but they have not yet received official names,
08:55and their classification remains impossible.
08:58Like these strange creatures, evolving in total darkness,
09:02remaining largely unknown,
09:04it is difficult to determine whether they or their habitats would really be threatened
09:08if mining in the high seas continued without a break.
09:12What specialists find is the need to study more,
09:17to collect more data, and to acquire a deeper understanding.