Did you know that the moon is rusting? No, not rustic, rusting. Well, that sounds impossible because rust needs oxygen and the moon, well, it doesn’t have it. Or so we thought. Apparently, Earth is leaking its air and it’s marinating the moon. It might have been like that for billions of years. What does this mean and why do scientists say it’s great news for a future lunar base? Well, let’s find out. A few years ago, the Indian Space Research Organization sent a probe called Chandrayaan-1 to orbit the moon. Its mission was to take some nice pictures, but it also was carrying a NASA-built instrument designed to chemically map the surface. The readings came back showing something scientists didn’t expect on the moon, hematite. It’s an iron oxide or in plain words, rust.
It’s the same red rusty material that eats through your garden fence or forgotten bicycle chain. Finding rust on Earth is normal because our planet is wet and airy. You need a strict recipe to make it happen. You need iron, you need water, and you need oxygen. The moon already has the first ingredient for rust because its surface is rich in iron from billions of years of asteroid impacts. But the other two ingredients are missing. There is no atmosphere to provide oxygen and there is no liquid water gathering on the surface. But it goes beyond that. Space actually hates rust. The sun constantly blasts the moon with the solar wind, a stream of fast particles made mostly of hydrogen. Well, these particles tend to strip oxygen away from rocks instead of adding it. All of that makes it obvious why hematite doesn’t belong anywhere near our satellite.
But these results don’t lie. The presence of hematite means that somehow, despite the vacuum and the sun’s particle stream, the moon is getting a steady supply of oxygen. It’s not coming from deep space or the lunar core. Also, the rust isn’t spread evenly. The data showed that the hematite is more concentrated on the side of the moon that faces Earth. The far side is mostly clean. Now, the only oxidizer close enough to do the job is Earth. We learned at school that Earth’s atmosphere ends at the Kármán line, about 62 mi up. That’s where space officially begins, but that’s just the thick part. In reality, Earth is wrapped in a gigantic invisible cloud of hydrogen called the geocorona. It’s enormous, it glows in ultraviolet light, and it stretches almost 400,000 mi into space. That’s farther than the moon’s orbit.
This means that despite being very far away, the moon is still within the outer edges of Earth’s atmosphere. If you were standing on the moon looking back at Earth with a telescope that can see ultraviolet hydrogen, Earth wouldn’t look like a blue marble. It would look like it’s wearing a huge, fuzzy, glowing halo. Now, when we picture Earth and the moon, we imagine a huge, clean gap between them, two worlds separated by nothing. But that nothing isn’t actually empty. The two are already connected by gravity, tugging on each other nonstop. But there’s another kind of connection most people never think about. Earth is surrounded by an invisible force called a magnetic field. It’s created deep inside the planet and stretches far out into space. We don’t see it, but it’s the reason compasses work and the sun doesn’t strip our atmosphere away.
This magnetic field doesn’t just stop at Earth’s surface. It doesn’t sit there like a perfect bubble, either. The solar wind pushes on it nonstop, stretching it out behind Earth into a long magnetic tail that reaches hundreds of thousands of miles into space, like a tail trailing behind a moving comet. That tail is how Earth’s oxygen ends up on the moon. The sun slams into Earth’s upper atmosphere, knocking oxygen and nitrogen atoms loose and turning them into charged particles. Normally, they drift off into space, but because they’re charged, Earth’s magnetic field grabs them and sends them backward down the magnetic tail. Most of the time, the moon is off to the side doing its own thing. But once a month, right around the full moon, it slides straight into Earth’s magnetic ponytail.
Inside that tail, Earth blocks the harsh solar wind and gives the moon a few days of calm. But it’s still moving straight through particles leaking from Earth. Those particles collide with the surface and react with the iron in the soil. Repeat that long enough and it adds up. Earth loses tiny traces of its air and the moon quietly collects them using its weak gravity like a slow, patient net. It’s like driving behind a dirty truck. Dirt flies off of it, but you don’t really notice until it starts sticking to your windshield. The same thing happens on the moon, except, you know, no windshield. We actually have proof of this happening in real time. A Japanese probe called Kaguya was hanging out in lunar orbit and its sensors spiked when the moon passed through Earth’s magnetic tail. It detected a surge of high-energy oxygen ions.
Scientists call it the Earth wind. It acts like the solar wind, except instead of being hot particles from a star, it’s made from leftovers of our own atmosphere. And this suddenly makes the moon part of a much bigger story. Scientists think this kind of atmospheric escape can help explain what happened to planets like Mars. The red planet doesn’t have a global magnetic field today, but long ago, it probably did. When that shield failed, its atmosphere had a much easier time leaking away. Studying Earth and the moon is like watching a version of that process on replay, just in slow motion. And it’s not unique. Near the edge of the solar system, Pluto’s thin atmosphere is slowly being stolen by its moon, Charon. Ooh, larceny in space. Pluto’s gravity is so weak that its atmosphere stretches far into space.
When those gas particles drift close enough, Charon’s gravity simply grabs them. No magnetic field needed, just a leaky planet and a nearby moon pulling the material away. Now, when the Apollo astronauts brought lunar soil to Earth, it was already loaded with hydrogen from the solar wind. The sun sprays the lunar surface with hydrogen and over time, that hydrogen gets baked straight into the dust. That’s the H, but you still need the O2 to create water. The regolith may already contain trace amounts of oxygen locked into minerals and dust, not as ice, but as something that can potentially be processed. It would mean that regolith is not just a nuisance that destroys gear and rovers. For a future lunar base, even small amounts matter. Water is heavy. Launching it from Earth is a nightmare.
If the moon can supply even part of what astronauts need, it could make a difference. Now, another cool side effect of this discovery is that drilling into the moon could tell us more about Earth’s history. You see, our planet is terrible at keeping records. It’s like a giant recycling machine. It’s always changing. Tectonic plates grind the crust down and melt it into magma. Winds and rains erode rocks. The air that we breathe now is different from the one that was around 2 billion years ago. Now, we can guess what the ancient atmosphere was like, but we don’t have a physical sample. The moon is the complete opposite. It’s cold and static. When those Earth particles land on the moon, they get buried under dust and stay there. They’re trapped in the crystal lattice of the soil.
Think of the lunar surface like an ice core in Antarctica. The deeper we dig, the further back in time we go. If we drill a core sample on the moon, we might, theoretically, find layers of oxygen and nitrogen from 2 and 1/2 billion years ago. That is right around the Great Oxidation Event, when microbes first started pumping oxygen into our atmosphere. That could tell us something we don’t know. It could prove that life started earlier than we thought. It could show us exactly how a dead planet turns into a living one. That’s another answer you can give the next time somebody asks why we should go back to the moon. Also, to find the green cheese. Hey, just Google it. So, in the end, will the sun be to blame for destroying our planet? Or how about a huge meteorite? Or some kind of disease?
Probably not. It seems that life will disappear for a very unexpected reason. Humans, animals, insects, fish, and most microbes will be wiped off the face of the Earth because of oxygen or, more precisely, because of its absence. Recent research has shown that the number of freshwater reservoirs with very low or no oxygen levels in coastal areas is increasing worldwide. Over the past 65 years, four times more oxygen-deficient waters have appeared in the world’s oceans. What does it all mean? It’s likely that life on Earth will vanish much sooner than the sun’s energies dries up all the oceans. The end is likely to come in a little more than 1 billion years. But this doesn’t mean that the planet will disappear, too. The period when Earth is filled with oxygen will make up just about 20 to 30% of the total lifespan of the planet.
So, we’re just temporary guests here. Just think how long that is, 1 billion years. The first Homo sapiens appeared only about 300,000 years ago. That is the entire history of humanity occupies less than a half a million years. So, relax. A billion years won’t pass very fast. By that time, humans won’t be on Earth anymore. We might master space travel and find a new planet in the vast depths of space. But, why can we lose air? As the sun heats up, the planet gets warmer and warmer, and this heat breaks down carbon dioxide, the gas which is necessary for all plants to photosynthesize. Without carbon dioxide, they can’t produce oxygen. With a drop in carbon dioxide levels, the methane content will increase, and this gas is quite harmful to us. Now, this all sounds logical, but this is a secondary reason for the lack of oxygen.
The real problem is something else entirely. As the sun becomes brighter, it will begin to heat rocks on Earth, such as granite and basalt. These rocks will start to break down faster. When they collapse, they take carbon dioxide from the air, which warms our planet. If there’s less carbon dioxide in the air, Earth should become colder. But, there’s a problem. The sun will shine more, and its heat will outweigh this cooling effect. So, even if rocks take away carbon dioxide, the sun will blaze so much that Earth will still become extremely hot. Next, when the sun shines more intensely, it, along with other natural factors, contributes to the breakdown of granite and basalt. These rocks mix with carbon dioxide and water to make carbonates, which go deep into the Earth.
This takes carbon dioxide out of the air, which means plants can’t make as much oxygen because they need carbon dioxide to do that. Besides, volcanoes release gases, which also reduce the amount of oxygen in the air. So, the sun, by destroying rocks, affects what happens inside Earth and controls how much oxygen there will be in the air. In about 1 billion years, the sun will become so bright that no rocks will be able to save Earth from its heat. And the escaping gases will halt photosynthesis and oxygen production. And then, our planet will return to the state it was in about 2. 4 billion years ago. To the time when the Great Oxidation Event began. And this event was much more important than, say, the first Olympic Games or the appearance of humans on the planet.
Billions of years ago, there was almost no oxygen on Earth. Instead, there was a soup of gases, such as nitrogen, ammonia, methane, carbon dioxide, and others. Yes, we have these gases in the atmosphere today, but there used to be a lot more of them in the past. It was difficult for any form of life to originate in such conditions. But, after some struggle, it succeeded. At first, Earth was inhabited by the simplest bacteria, including cyanobacteria. They learned how to make oxygen using sunlight, water, and carbon dioxide. These bacteria worked for millions and billions of years and made so much oxygen that it began to accumulate in the air. This is what we now call the Great Oxidation Event. It was like a great celebration of life because with oxygen, new living beings could appear.
But, by the way, cyanobacteria didn’t learn photosynthesis because they were like, “Oh, let’s make oxygen. It’s so cool. ” No, oxygen was just a byproduct. Cyanobacteria wanted only one thing, to get as much energy as possible. And for this, they learned photosynthesis. It helped them store energy using sunlight. They use special pigments to absorb light, and the result of this process was the release of oxygen. This had been going on for hundreds of millions of years, and then, at some point, they made too much oxygen. This oxygen started to spoil other gases that had been there before. For example, it ate a lot of methane. Because of this, Earth cooled down a bit, and the Ice Age began. But, that’s another story. In short, in a billion years, we risk going back to that difficult time.
But, let’s hope that we’ll manage to move to another planet on our spaceships or come up with some other solution. And what’ll happen to our home planet next? Will new life be able to originate there without so much oxygen? Well, it’s possible, but it’ll be much more difficult. This will require another source of energy besides the sun. It can be, for example, hydrothermal vents. And by the way, there are ecosystems on Earth that use this type of energy. You can find one of them in the Movile Cave in Romania. Imagine a place where there’s little oxygen. It’s dark. The sun’s rays don’t reach there. Over millions of years of evolution, a unique and slightly creepy life has developed in this cave. It was first discovered in 1986, and scientists are still exploring this place.
The entrance to the cave is just a small hole in the ground. A narrow tunnel goes deep underground. Inside the cave, the air is filled with hydrogen sulfide and carbon dioxide. And there’s half as much oxygen there as on the surface. A human can’t stay there without a special mask. But, for local forms of life, this is home, and they feel great there. There are several dozen species living in the cave, and many of them aren’t found anywhere else on Earth. Here, you can see strange little monsters, white snails, white spiders, centipedes with long whiskers, transparent shrimp, and even unknown species of leeches. Since there’s no light in the cave, all these creatures don’t need eyes. They’re blind. But, they have long, sensitive antennae and paws that allows them to navigate in the space.
They also have no colored pigment, so all these bugs and spiders are either white or transparent. But, if there’s so little oxygen there and nobody does photosynthesis, then how does all this life survive? It’s all thanks to the unique bacteria autotrophs. They absorb carbon dioxide and produce nutrients. These bacteria are food for other organisms, and those, in turn, become food for larger creatures. So, a whole food chain has been built in the cave, which provides all the inhabitants with food. Evolution has created a unique ecosystem that exists separately from the rest of the world. It’s like a small universe that has developed according to its own rules. However, this universe is not expanding because all living beings here can’t live away from hydrothermal vents and autotrophs. Otherwise, where would they get their energy from?
But, let’s imagine that the sun cools down, almost all the oxygen disappears, and the entire planet gets covered with hydrothermal vents. It’s dark, and the air is filled with methane, CO2, and other substances. And somehow, life begins. Even people appear at one point. What would they look like? Pale, thin, and blind creatures with very long arms that help them navigate in space. They have pets, large centipedes or cockroaches that move silently on the ground. People are also quiet because they don’t have lungs filled with air to scream. There’s silence in the world. People communicate through touch. No one travels. Everyone lives separately next to their hydrothermal source. The whole world has turned into a horror movie in a billion years. Hey, listen up. There’s a red alert. NASA supercomputers have calculated that there are only 2,021 years left until the end of the Earth.
Our planet is about to Oh, wait a minute. Oops, I’m sorry. I thought these zeros were a mistake. Well, the research actually says 1 million 2,021 years in the future. Woo, that’s a relief. Breathe normally. Still, this means that our planet officially has an expiration date. And no, this is not science fiction. It’s a very real study that shows how, why, and when life on Earth will end. So, thanks to NASA and Japan’s Toho University, we can now mark the calendar. It’ll happen in around a billion years. But, what about how and why? Well, even as recently as the early 20th century, scientists still didn’t know what powered the sun. One of the first big ideas was that the sun was basically a giant piece of charcoal, just a huge ball of fire burning some kind of fuel. But, that was easy to rule out.
At the rate the sun puts out energy, it would have burned through that kind of fuel in just a few thousand years. And even back then, geologists and paleontologists already agreed that Earth was at least 100 million years old, if not more. That meant the chemical burning couldn’t have possibly kept the sun shining for that long. So, scientists turned to another, more nerdy theory, gravitational contraction. This idea was that the sun shines because of its own weight. Its gravity pulls all the gas inward, squeezing itself tighter and tighter. It’s kind of like warming your hands by rubbing them together. We know that gas giants like Jupiter and Saturn are slightly contracting under their own weight and giving off more heat than they get from the sun.
So, yeah, gravitational contraction, also known as the Kelvin-Helmholtz mechanism, is very much real, but it’s not what powers the sun. When researchers did the math, it showed the sun could only shine like that for about 20 to 30 million years. Eventually, scientists learned that the real secret behind the sun’s power and longevity was something way more powerful, nuclear fusion. Now, deep inside the sun, it’s unbelievably hot. We’re talking 27 million degrees Fahrenheit, and it’s under crazy pressure because the sun is so big and heavy. All that heat and pressure squashes hydrogen atoms and forces them to stick together. When four hydrogen atoms get squished hard enough, they turn into something new, a helium atom. When that happens, a little bit of their mass turns into energy, and that’s what becomes sunlight and heat.
For centuries, people feared the sun would someday go cold, and that will happen eventually. About 5 billion years from now, our star will run out of hydrogen, and gravity will take over. But long before that, Earth will already be toast. According to a NASA life extinction prediction, our planet will become a scorched, uninhabitable rock, not because the sun will go out, but because it will burn too hot. It turns out that those old apocalyptic ideas were not completely off. The sun will destroy life on Earth, just not by going cold. But why? Well, it’s because with time, the sun is getting brighter, and I’m not talking about its mood. It releases more energy. It’s a slow, natural side effect of the nuclear fusion we just mentioned. Deep in the core, the sun has been fusing hydrogen into helium for billions of years.
But as more helium piles up, the core gets denser and hotter. Think of it like a pressure cooker. The more pressure builds up inside, the more heat rises from within. That extra heat speeds up fusion, which means more energy gets released, and the sun starts shining just a little bit brighter. It’s not dramatic. We won’t notice it in a lifetime, but the future proof Androids we’re going to build just might. With time, the extra heat adds up. The sun is already about 30% brighter than when the Earth was born. But life decline is going to happen much, much earlier, even before the given deadline. As the sun keeps cranking up the heat, Earth is going to sweat. The extra sunlight raises global temperatures to the point where the ocean surfaces hit around 117° Fahrenheit. That’s hot enough to mess with the planet’s entire climate system.
Water vapor begins to rise from the oceans and accumulate in the upper atmosphere. This causes even more heat to be trapped, creating a thick, humid layer around Earth. Scientists refer to this ongoing cycle as the moist greenhouse effect. The rising temperatures aren’t just drying out our planet, they’re also harming plants. Plants rely on carbon dioxide from the air to grow and thrive. However, as Earth warms up, certain natural processes can take too much carbon dioxide out of the atmosphere. When that happens, there won’t be enough CO2 left for plants to survive. Forests will disappear first, then grasslands, bushes, and even the toughest plants that usually handle extreme heat. This all will lead to oxygen collapse because plants and CO2 are crucial for photosynthesis.
In simple terms, this is how plants use sunlight, along with water and carbon dioxide, to create their own energy and produce oxygen as a waste product. Right now, oxygen makes up about 21% of Earth’s atmosphere. But once it drops below even 1%, complex life as we know it will most likely disappear. Earth’s biosphere will shrink to just a few microbes and extremophiles hiding deep underground. But even they won’t last long. It’s worth noting that scientists ran two versions of the simulation, one with life like we have today, and one with none at all. Surprisingly, both worlds lost their oxygen at about the same time, around 1 billion years from now. That means plant life and photosynthesis do help, but they’re not the main thing keeping oxygen in the atmosphere.
It’s actually a long-term chemical battle between volcanic gases and rocks that gradually soak up oxygen like a sponge. And even after most life is gone, the heat will keep going, causing oceans to boil. Not all at once, but slowly and steadily, the oceans will begin to evaporate into the atmosphere. But that vapor won’t just come back down as rain like it does now. Why? The atmosphere will be too hot and thick for that. Instead, sunlight will start breaking the water apart, and hydrogen will escape into space permanently. Once it’s gone, it’s gone for good. Basically, instead of raining back down, Earth’s water will slowly leak into space until there’s nothing left. Even before the last puddles vanish, life under the sea will be long gone. Once the balance of temperature and oxygen is lost, not even the hardiest ocean life can hold on.
In the end, Earth will become something we can barely recognize, a dry, lifeless rock. There will be no water, no oxygen, and no life left. The oceans will be gone. The atmosphere will be thin and toxic. Even the most resilient microbes will have disappeared. However, the sun will still shine in the sky. Earth will keep orbiting just like always. It’ll still be a planet, just without life. But long before that cosmic finale, Earth will already be uninhabitable, which raises the big question. So, what could future humans do about all this? Well, escaping sun radiation and extinction might end up being humanity’s biggest engineering challenge yet. Maybe we’ll build massive space colonies and leap from planet to planet, staying just ahead of the sun’s deadly heat.
Even if we terraform Mars, making it more Earth-like so we can inhabit it, it’ll still be cooking in the same solar oven, just on a lower shelf. Or maybe we’ll live in giant rotating space habitats like O’Neill cylinders, floating mini worlds with gravity and recycled air, water, and energy to support long-term survival. Those could drift farther and farther from the sun as things heat up. Or who knows? Maybe we’ll upload our minds to the cosmic cloud or hop into a higher dimension and watch the universe like it’s, you know, Netflix. Okay, this is definitely too nerdy, and we’re going deep into sci-fi territory. But whatever the solution may be, humankind has a long time ahead to figure out how to survive the eventual end of Earth and life, or maybe even preserve it in whatever form it takes. So, listen up.
One day, our sun will cool down and turn into a white dwarf. But this is not the worst thing for Earth. Before the star cools down, it will grow to an incredible size and arrange Ragnarok for us. Now, in case you don’t know, Ragnarok is the fire apocalypse from Norse mythology. So, our star will burn down absolutely everything on our planet. But hey, don’t worry, there’s good news. This one day will come in 5 to 7 billion years. The bad news, though, is that almost all complex life on Earth will become extinct much sooner, maybe in a quarter of a billion years. But there’s a small chance that our planet will be ruled by octopuses. Yeah, I know, this is too much news for the first few seconds. So, let me break it all down for you one thing at a time.
