The Earth itself was formed 4.54 billion years ago. And then between 40,000 and 1 billion years in the past, life sprang up on our young planet. But what befuddles researchers is all the stuff in between: What is the perfect life-creating recipe?

In other words, experts have thoughts and theories about how life started, but we’re still missing its coming-of-age montage. Fortunately, a recently discovered 550-million-year-old rock is helping the experts finally understand a little more about where we came from.

Charles Darwin believed life came from “warm little ponds.” Water-repelling particles formed a barrier around other random microscopic materials in the water, and with some time, poof, you’ve got yourself some high-quality life. For the last century, experts worked with this idea.

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Understanding how life began on Earth, the experts thought, starts with oxygen. Because all of Earth’s complex life requires the gas, scientists believed early organisms were created when oxygen levels rose in our atmosphere. They were wrong.

See, in past studies, scientists theorized that complex beings popped up about 700 or 800 million years ago. When things were more stable between ice ages, life would have had a much easier time evolving. But there was a conflict with this number.

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Ironically, the history of oxygen is much murkier. For the first two billion years on Earth, there was no oxygen on our little planet. And then 2.3 to 2.5 billion years ago, the gaseous element began to appear.

Studying fossilized coal deposits helped researchers realize that there wasn’t enough oxygen in the atmosphere for forest fires until 400 million years ago. This still leaves 2.1 billion years of low oxygen levels, but life still existing. 

During the 2.1 billion years, the oxygen levels in the air eventually reached such a level that it oxygenated the sea around 540 to 420 million years ago. Scientists discovered this by looking at iron levels in rocks. Not just any rocks, though.

These were created by undersea volcanoes. Millions of years earlier, when the rocks were still forming, ocean water ran through the components, leaving behind clues for researchers to interpret.

NOAA

By studying these traces, scientists discovered a time period for the oxygenation of the water. This further proved that life was developing on Earth without having a major need of oxygen. Scientific communities struggled to make sense of this.

Darwin’s thinking was flawed. Oxygen levels skyrocketed after life started and not before it arose. This means the element wasn’t as important of an ingredient for the life creation recipe. Experts weighed in.

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“This [suggests] the origination of early animals, which required O2 for their metabolisms, may have gone on in a world with an atmosphere that had relatively low oxygen levels compared to today,” said Daniel Stolper, Ph.D. (right), an assistant professor of Earth and planetary science at the University of California, Berkeley.

This information complicated things for the researchers who were convinced that oxygen equalled life. Learning new information can complicate your old beliefs and is entirely necessary for moving humanity forward as a species. So, oxygen was out.

Scientists couldn’t be kept down for long though. In 2017, they suggested a different life-arising theory — algae growth. Throughout evolution, it seems the two developments existed side-by-side in a symbiotic relationship.

Regardless, one issue soon became clear in the scientific community: reaching a consensus was going to be difficult. This was illustrated by just how many theories scientists were kicking around.

Lightning is another possible life-creating culprit. When electric sparks combine with an atmosphere filled with water, methane, ammonia, and hydrogen, they can made amino acids and sugars — two key building blocks of life.

Jerry Zimmer

Or, instead of being trapped by hydrophobic molecules, life ingredients may have had a serendipitous rendezvous on clay. Clay is porous and sticky, making it an easy spot for these ingredients to spend some time together.

Some researchers believe that deep sea vents are the key to life’s creation. These odd natural features spew molecules with hydrogen, which assists in critical reactions for mineral catalysts. Other theories are a little more… out there.

One proposed by the less-scientific community is that life didn’t begin on Earth. Aliens brought life here to influence evolution in some way. This could be done remotely with ultra-sophisticated ship tech.

Mark Garlick

Other species might not even need pilots to sail them across space. With advanced robotics and imaging systems, they could send ships out alone, wait for them to arrive at their intended destination and then deposit their DNA starter material.

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Another theory, very similar to this one, is that a meteor may have picked up some kind of alien genetic material and then crashed into Earth. Very similar, except done entirely through accident.

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Though we still don’t know truly know how life on Earth began, we do know this, according to Paul Niles, NASA planetary geologist: “[Life] “doesn’t need a nice atmosphere or temperate surface, but just rocks, heat, and water.”

NASA

The good news for scientists is that there’s no shortage of mysteries to be solved about life’s origins. Dominic Papineau, a geologist at the University College London, had his sights set on the other biggest question of all time.

Though many tried and failed before him, Dominic wondered if he could determine the origin of life on Earth. He looked to a peculiar region of his native Canada for that answer. In 2008, he planned a trip to the Nuvvuagittuq Supracrustal Belt.

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Scientists have previously investigated this site, which was a hotbed of volcanic activity long ago. But rather than search for fossils, Dominic was on the hunt for something on the smaller side, a subject you could only see through a microscope.

His expedition wouldn’t revolve around any kind of “missing link,” as Dominic hoped to find an organism that appeared billions of years before humanoid life. Of course, such a simple and tiny thing would be unlikely to leave behind much evidence.

Nicki Swift

The Nuvvuagittuq Belt, located in the far regions of Quebec, stands out even to the untrained eye. Layered iron formations striped across the landscape, with quarter-sized swirls dotting certain rocks. Dominic and his UCL colleagues approached them, hammers in hand.

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These mineral sections set off an alarm in Dominic’s head. They resembled structures formed by microscopic creatures in underwater vents, so he couldn’t help but make a connection. The geologist excitedly smashed the specimen right off the cliff.

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Dominic’s team of geologists and researchers repeated that process dozens of times, as they amassed over one hundred pounds of rocks. However, they couldn’t tell whether or not these samples added up to anything just by looking at them.

Only close analysis could prove or refute Dominic’s theory. He took the rocks to the Carnegie Institute for Science in Washington D.C., where researchers sliced them into cross sections and took a look at their composition.

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The microscope revealed filaments running throughout the stone. Papineau and his colleagues felt almost certain that only organisms, not any kind of natural erosion, could have created such a pattern. But that wasn’t the most striking aspect.

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These remnants dated back sometime between 3.77 and 4.28 billion years ago. Assuming the geologists hadn’t made any errors, they realized they might have discovered proof of the earliest life on the planet.

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Papineau knew he had to tread lightly. There were plenty of scientists before him who made such a bold claim and, once proven wrong, found their careers and reputations in shambles. Still, he figured they had a strong case.

Dominic proposed that these microbes could’ve harvested nutrients from the iron and chemical reactions happening throughout the region. In a way, they could be very similar to the organisms found thriving in toxic deep-sea vents.

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And such ancient forms of life would have needed to be hardy and adaptable, too. Dominic’s testing dated them to the Hadean Eon, a time where the planet was filled with storms and eruptions — it was basically Mordor for billion years.

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Then, as environmental conditions became less hostile, these microbes could have slowly evolved into all manner of species. Dominic stood by his theory, though many in the geological community dismissed his claims.

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This was no surprise, remember, as there has always been disagreement about the origin of biological life. Charles Darwin speculated that a particular chemical reaction in a “warm little pond,” could’ve caused it. But many competing theories have popped up since.

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In the 1990s, paleobiologist J. William Schopf announced he’d discovered 3.5 billion year old bacteria in Australia. His peers, however, soon accused him of exaggerating his claims just so he could make history. And he wasn’t even the debate’s most controversial figure.

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Some thinkers believe that life traveled to Earth on a meteor, though most scientists hotly reject this explanation. In fact, back in the 1600s, a cosmologist named Giordano Bruno was burned at the stake for popularizing such a claim.

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With dissension on all sides, Dominic continues to examine his findings. He knows that their investigation affects far more than just a group of bickering biologists. It could mean everything for the future of humanity.

If life could exist in such harsh conditions on Earth, then it might not be so out of the question for organisms to exist on other planets. Dominic’s success could kick-start a search for life on Mars. Recently, scientists have looked into other outer space locales.

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In 2019, China made space history as the first nation to ever land a probe on the far side of the moon. The science community lauded the accomplishment, but it turned out the Chinese had another bombshell to drop.

NASA Space Flight

Wu Yanhua, the deputy director of the China National Space Administration, opened up about their big plan. Detailing the purpose of the Chang’e 4 Mission, he explained that his government was particularly interested about life on the moon.

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There weren’t any humans aboard the spacecraft, but the “scientific exploration phase” did concern every man, woman, and child on Earth. They sent several types of organisms up there — not just to survive, but to thrive.

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The animal kingdom was represented by a colony of fruit flies. Anyone who’s ever found these pests in their home knows how persistent they can be. Still, the more intriguing part of this experiment hinged on a very different creature.

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The CSNA shot all kinds of plants up to the moon, except not in mature form. Instead, they focused on various types of seeds, ranging from potato to cotton plants, with the bold objective of growing crops on the moon.

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This decision raised immediate comparisons to the sci-fi flick The Martian. In one memorable sequence, Matt Damon’s stranded astronaut character cultivated potatoes using his own excrement as fertilizer. Minus that gross ingredient, the Chinese had very similar aims.

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With pollution and climate change jeopardizing the sustainability of life on Earth, this trial could provide a viable alternative. If we could grow food on the moon, then it suddenly wouldn’t be too hard to imagine settling there.

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With the spacecraft hurtling toward the moon, the mission was officially underway. Of course, the CSNA didn’t just send a potted plant up into the airless vacuum of space. They had an arsenal of gadgets at their disposal.

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The seeds wouldn’t enter the moon soil directly, but rather germinate in a biosphere. Inside, it would receive temperature-controlled air and a steady supply of water. It was a slam-dunk plan — on paper at least.

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Once the probe completed its lunar landing, it deployed the biosphere. Cameras and scanners would monitor every development of the fly eggs and seeds, though some skeptics doubted they would make any strides.

Were they right? The non-plant life — the fruit fly eggs and a yeast colony — fizzed almost immediately. From there, the Chinese scientists put all their hopes in their space garden.

Over a week passed with no results. Given the ambitious nature of the plan, a failure to cultivate crops wouldn’t be a huge loss, but still a disappointment. One detail, however, caught the entire agency by surprise after nine days.

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Though they’d planned it all along, the CSNA scientists still felt like they’d been struck by lightning when they saw the little sprout. The cottonseed was growing! They shared the news with the world right away.

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Their success wasn’t limited to a single leaf either. Multiple cotton seedlings popped up out of the soil, becoming the first plants to grow (in a specially-designed box) on the moon.

Would China soon have enough cotton to make t-shirts for all their future moon colonists? They were ecstatic about their accomplishment and envisioned a monstrous amount of vegetation spreading across the satellite. However, they failed to foresee one complication.

The Dissolve

Even with the constant heat the biosphere provided, the temperature fluctuated wildly. The unrelenting cold of outer space proved to be a bigger problem than the CSNA realized. All of the cotton withered away.

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In the aftermath, the Chinese government diplomatically announced that this experiment had ended. The other objectives of Chang’e 4 went on. Still, experts around the world were energized by this fleeting success.

Simon Gilroy, a botanist at the University of Wisconsin-Madison, recognized the experiment as a key step in sustaining life on the moon. “It’s fantastic to be able to sort of say, yeah, it’s a first tiny step down that path,” he said.

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After all, no one expected a few cotton plants alone to make a lunar colony possible. But these sprouts represented one large step for mankind, and very well may have secured our future. The Earth is in more danger than most people realize.

Moon Bridge

We know NASA best for launching astronauts and satellites into orbit. So would it surprise you to learn that a team of their scientists is studying models of a doomsday-devastated New York City? This is no side project, either; they’re deadly serious.

The man behind this peculiar mission is Lindley Johnson. A 23-year veteran of the Air Force, he joined NASA’s ranks in 2003. Ever since, his mind has mostly been fixated on the end of the world.

Politico

But don’t worry — Lindley is no crackpot. He’s not urging on the apocalypse, but rather approaching it from an analytical standpoint. Lindley serves as NASA’s Planetary Defense Officer, so nobody is better equipped to take on doomsday than he.

While humanity does a pretty good job of endangering itself on a daily basis, Lindley doesn’t worry about terrestrial threats. He’s more concerned with space rocks. Granted, most meteorites that come down to Earth are pretty small, or even microscopic.

However, what if an asteroid — one multiple football fields in diameter — was hurtling toward our planet? Odds are pretty good that it would land in the middle of the ocean, but Lindley wants more than luck on his side.

That’s why his NASA team investigates (hypothetical) cases of giant asteroids hitting densely urban areas. Thousands of years typically pass between such catastrophic events, but Lindley intends to be ready at any point.

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After all, Earth’s geography proves just how destructive a collision can be. NASA certainly doesn’t wish to see Midtown Manhattan turned into a crater, but they are interested in exactly how far that damage would spread.

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Lindley’s team continually runs simulations to get a better idea of where asteroids are most likely to strike, plus what kind of damage we can expect. In some cases, a collision may be inevitable. But Earth isn’t totally helpless.

Purdue University

For years, Lindley and his colleagues were operating on a shoestring budget. Fortunately, a 2015 audit convinced Congress just how essential planetary defense could be. They immediately buffed up Lindley’s annual spending power from $5 million to $50 million.

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With more resources on his side than he ever imagined, Lindley has led the charge against galactic peril. His NASA team assembled an arsenal of data and cutting-edge technology to keep asteroids at bay.

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NASA keeps this fact on the down-low, but they’ve cataloged over 2,000 asteroids in our solar system capable of obliterating an entire continent. Blowing up such a massive rock might cause too much fallout, so Lindley has other tricks up his sleeve.

The most promising method to redirect an asteroid is through the use of kinetic impactors. These unmanned spacecraft would crash into an asteroid at high speed, thus deflecting it away from our planet. Think of it as a game of high-stakes billiards.

With all due respect to fans of Armageddon, Lindley doesn’t believe that landing on an asteroid would be the most effective solution. Still, NASA hasn’t taken that option off the table.

The Independent

Astronauts have trained for complex asteroid landings, though nobody has ever attempted the feat. NASA foresees this operation more as a way to collect mineral samples, but there’s always the chance they’ll go full Michael Bay in an emergency.

NASA has a selection of hypothetical fixes to choose from, though they’re also ramping up their asteroid prevention in more concrete ways. For instance, they’ve installed more orbital telescopes to monitor any life-threatening space rocks in the solar system.

Harvard University

The capability to spot catastrophe coming could be the most important factor in the end. Most deflection techniques require months or years to mobilize, so a few days notice won’t help at all. The good news is that NASA isn’t alone in this fight.

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Lindley’s team ran exercises with FEMA — the Federal Emergency Management Agency — to prepare for collateral damage from a collision. “They are a great way for us to learn how to work together and meet each other’s needs,” Lindley explained.

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In 2019, Lindley also organized a conference with the European Space Agency and the International Asteroid Warning Network. Working together, they’ll have eyes on the sky all over the world.

While it seems unlikely that we’ll have to deal with an impending apocalypse, civilization is better prepared than ever. That news will only disappoint doomsday preppers, who may very well have stocked up their bunkers for nothing.

In spite of the life-or-death consequences of his job, Lindley says he sleeps just fine at night. It’s just another day at NASA. Besides, Lindley can name plenty of colleagues who have responsibilities that might be even more trying than his own.

Futurism

Lindley likely couldn’t handle George Aldrich’s job. When George’s teacher told him to “shoot for the stars” as a child, he took that advice pretty literally. Fast forward several decades, and he’s caught way more than just a whiff of success at NASA.

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Growing up in New Mexico, George watched his dad fly up the Navy ranks and join the coveted Blue Angels. He always dreamed of reaching such soaring heights, and so he looked for a heroic job as soon as he finished high school.

George started a bit smaller. He volunteered for the local fire department, and his recent chemistry and mathematics experience piqued the interest of the chief. He signed up George for a special task on the force.

While he didn’t extinguish many infernos, George stood out on the department’s odor panel. By training his sense of smell, he could sense problems like gas leaks before they had a chance to ignite. Soon, George realized he was meant for bigger and better things.

In 1974, his chief recommended that George take his talents to the next level. NASA had a firm presence in the area, so perhaps, George figured, he could secure a position there. At the same time, not just anybody could waltz in and apply to be an astronaut.

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After the Apollo 1 disaster — in which a technical function aboard a shuttle killed all three crew members aboard — NASA was taking safety seriously. They needed staff who could prevent disasters most people would never see coming.

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After sending in his application, George had to take a strenuous exam to see if he was made of the right stuff. Hours later, he set his pencil down and headed home, waiting for a phone call that would make or break his dreams.

Then the good news came in: NASA told George to report to the White Sands Test Facility immediately, where he would begin his new role as a Chemical Specialist. But what exactly did that mean?

Well, if you asked George about his job, he would describe himself as a “Nasalnaut” or the “Chief Sniffer.” That’s because his real responsibilities boil down to smelling anything that NASA sends into space.

NASA

Odd as it sounds, George’s role makes sense. Astronauts go into space for long periods of time, stuck in close quarters, breathing in recirculated air. The last thing command wants is any harmful odors or substances traveling along with them, smelling up the shuttle.

NASA / Don Pettit

That’s precisely where George and his team come in. They personally inspect the smell of every piece of cargo and gear to make sure everything is ship-shape. Of course, nobody has been sniffing for longer than George.

He holds the NASA record for the most official sniffs, with his number approaching one thousand. Naturally, George’s system is more nuanced than just judging a scent as good or bad.

The odor panel blindly scrutinizes each object, so their everyday conceptions about the items won’t cloud their judgment. From there, the sniffers rank everything on a scale from 0-4. If something scores higher than 2.5, they suggest leaving it on Earth.

Between tests, George might cleanse his palate, so to speak, using a trick developed by perfumers. He simply resets his nostrils by smelling the back of his own hand, which is sometimes called “going home.” And his work has likely saved lives.

A manned space mission involves so many complex chemical reactions, that NASA cannot risk any toxic materials sneaking aboard. The astronauts themselves may not be able to detect it, so they require an expert nose to do it for them — and more.

Much of the time, the most problematic materials aren’t what you would expect. George has found that old-fashioned camera film, for example, can be surprisingly toxic. Meanwhile, other items can just get downright disgusting.

Something as basic as velcro can stink up an entire space shuttle. George once determined that while separate velcro straps have no real odor, together they can produce an unbearably pungent smell. But not every scent can be swept away.

George says that when it comes down to it, humans really stink, and there’s not much NASA can do about it. Because of basic functions like sweating and going to the bathroom, astronauts need to learn to live with a little odor.

After 44 years, George is still going strong. He estimates that he’s only ever missed two tests — due to sickness — over his entire career. You could say he wrote the book on odor testing, and he’s definitely smelled that book as well.

NASA