WhatsAppRedditShareEmailTweetPin0 Shares
The universe is full of paradoxes and contradictions. Most of us still cannot comprehend its infinite dimensions. But often, what seems impossible is explained by a lack of data—or faulty assumptions and models.
To prove it, here are eight incredibly ancient objects (from Earth to outer space) that once defied—and in some cases still defy—our understanding of cosmic timeline.
8. Impact craters two billion years old.
The oldest impact craters on Earth formed billions of years ago. But how is this possible? Given the enormous geological upheavals during this time, one might expect nothing to remain of them. Even the continents are no longer in their original positions and have not retained their original shape.
Yet, the Vredefort crater in South Africa remains recognizable despite its two billion-year age. This is partly due to its size. It is the largest impact structure on Earth, with a diameter reaching 300 kilometers in places. Furthermore, due to the scale of the impact, the crater was buried under a layer of ejecta, protecting the remaining portion from erosion.
Even older is the Yarrabubba impact structure, formed in Australia 2.23 billion years ago—the collision that helped end the Ice Age. Although it can now be identified primarily through mineral analysis, it continues to serve as a time capsule for scientists, providing information about Earth's early history.
7. Minerals older than the earth's crust.
As mentioned, the surface, or crust, of our planet has been continuously transformed over billions of years. Continental drift, which divided the supercontinent Pangea into the continents we inhabit today, is only part of the story. The Earth's crust was also formed by volcanic eruptions and asteroid impacts, particularly during the Hadean Eon, 4.6 to 4 billion years ago. During this period—which spanned the formation of the planet and the origin of life—Earth was a "fiery hell." "Under constant meteorite bombardment," it was "filled with volcanoes spewing lava onto the surface." As a result, there is no geological evidence; all the rocks were broken down and recycled again and again.
However, in 2001, researchers dated a zircon sample to 4.4 billion years ago—the period when the Hadean period was in full swing. These crystals, discovered in the Jack Hills region of Western Australia, not only survived the bombardment from space but also the intense heat and pressure of terrestrial reworking. But how? They are not as hard as diamonds, and their melting point is much lower (2500°C versus 4500°C).
In fact, the region where the zircons were discovered likely contains diamonds of a similar age, although the oldest ones found so far are only 4.25 billion years old. Therefore, older and rarer zircon crystals represent a more valuable time capsule. They give us insight into Earth's earliest history. We have learned, for example, that liquid water may have existed as early as 4.3 billion years ago. This may mean that the Hadean period was much colder and perhaps more hospitable to life than previously thought.
6. Prehistoric sunlight
Everyone knows that when we look at the stars, we look into the past. By the time the light reaching our eyes reaches ours, they have reached an age equal to the light-years the star is located. Therefore, when we look at our Sun's nearest neighbor, the Alpha Centauri system, located approximately four light-years away, we see what it looked like four years ago. That's when the light reaching our eyes first left the star's surface. Likewise, the yellow hypergiant Rho Cassiopeiae, the farthest visible star, located 8,150 light-years away, looks the same today as it did more than eight millennia ago—2,000 years before the first civilization arose on Earth.
How then is it that light from our Sun, whose distance is measured in light minutes, reaches us at the age of 10,000 years?
The answer has to do with the Sun's density. Even though photons travel at the speed of light, they take a very long time to leave the Sun. Starting from the core, they make a winding journey through 695,508 kilometers of dense solar material. Some reach the surface in 10,000 years, while the slowest can take 170,000 years—in that case, we see the light generated when humans first put on clothing. However, once photons reach the Sun's surface, they take only 8 minutes and 20 seconds to travel 150 million kilometers of open space and reach our eyes.
5. The Moon, which existed before its planet.
After Jupiter's Ganymede, Titan is the second-largest moon in the Solar System. In fact, it's larger than Mercury. Unlike most moons, it also has a substantial atmosphere—opaque, orange, and denser than Earth's. Its formation long remained a mystery. But it's now believed that Titan's nitrogen-rich atmosphere originated somewhere in the Oort Cloud—the icy outer shell of the Solar System. In other words, it didn't form, like Saturn's other moons, from rings around its planet.
As it turns out, analysis of the nitrogen isotope composition on Titan does indeed indicate that it is significantly older than Saturn, and perhaps even the Solar System. Researchers believe it has more in common with Oort cloud comets than with other moons or planets. This makes Titan the only known moon that predates the planet it orbits.
4. A cosmic megastructure whose age is almost equal to the age of the Universe.
Cosmic megastructures, from voids to superclusters, are the largest known structures in the Universe. Examples include the Giant Arc (a 3.3 billion-light-year-long chain of galaxies), the Great Ring (a 4 billion-light-year-long circle of galaxies), and the Great Wall of Hercules and Corona Borealis (a 10 billion-light-year-long cluster of galaxies formed by gamma-ray bursts). There is also the Bootes Void, or Great Nothing—a spherical space, mostly empty and starless, with a diameter of 330 million light-years. Each of these defies our models of the cosmos. For example, the Bootes Void should be full of thousands of galaxies, not just its modest 60. And the rest defy the cosmological principle, which limits their possible size to just 1.2 billion light-years.
However, these megastructures are unlikely to have formed by chance, suggesting that the problem lies with our laws and theories, not with the Universe as a whole.
But there's one megastructure that defies more fundamental phenomena. The Hyperion Supercluster is incredibly huge for its age. Galaxies must first form, grow, and collide with each other before clusters can merge into superclusters—and all of this takes many billions of years. Yet Hyperion formed less than two billion years after the universe began. Viewed from a distance of 12 billion light-years (as it appeared 12 billion years ago), Hyperion is 200 million light-years in diameter and 500 million light-years long. That's twice the width of our own Milky Way Galaxy and 5,000 times its mass—not bad for a structure that appeared in the blink of an eye.
3. Matter that is older than the Universe.
Although invisible, dark matter is thought to make up 851 TP3T of the universe. Essentially, it's the glue that holds everything together. We don't know what it is, but we know it exists; without it, we wouldn't have galaxies. Their rotational speeds would have torn them apart billions of years ago.
We can also observe the gravitational influence of dark matter by examining its outer edge, where, despite their relative distance, stars orbit the core at the same speed as stars further away. This isn't what we would expect if the galaxy's gravity came primarily from its constituent stars, which are most densely packed at the core. So, given its importance, it's surprising that we know so little about it. We don't even know how old it is—but some believe it's older than the universe itself.
First, modern theories suggest that the Big Bang, which gave rise to the material universe, occurred after a period of inflation—the inflation of quantum forces, which in a tiny fraction of a second expanded nothingness to unimaginable proportions. Dark matter is believed to have emerged from this process, followed much later by ordinary matter and radiation, formed by the decay of quantum forces.
Another reason to believe dark matter is older than the universe is that it appears to have existed forever. Researchers looking for evidence of its destruction through interactions with ordinary matter or radiation have found none, suggesting either that it is too elementary to decay into anything else or that it does not interact efficiently enough to decay. In any case, given that we have not observed signs of dark matter dying, its lifetime is estimated to be at least one hundred quadrillion years—almost 10 million times longer than the current lifetime of the universe.
2. A star that is older than the Universe.
The star HD140283, located in the constellation Libra at a distance of 190.1 light-years from Earth, is the oldest star in the universe. Nicknamed Methuselah (after the oldest person in the Bible), it was originally estimated to be 16 billion years old. However, this is 2.2 billion years older than the age of the universe. Scientists were puzzled.
Although later studies, conducted 13 years after the star's discovery in 2000, dated its birth to 14.5 billion years ago, and then to 14.3 billion, this still didn't make sense to astronomers. After all, the universe is thought to be only 13.8 billion years old, based on analysis of the cosmic microwave background. How could a star be older?
Another eight years passed, during which scientists puzzled over the star's age, until in 2021 the age of the star was revised to 12 billion years. But this still didn't resolve the paradox, as some now argued that the universe is younger than we thought. New measurements of cosmic radiation lowered the possible age of the universe to 11.4 billion years—600 million years younger than the conservatively estimated age of Methuselah.
One explanation for this paradox involves temporary changes in dark energy, which influence the rate of acceleration of the universe's expansion. Whatever the cause, one thing is clear: resolving the Methuselah paradox is key to our understanding of the cosmos.
1. Black holes are older than the Universe.
Primordial black holes may be as old as the universe itself, dating back to the Big Bang 13.8 billion years ago. And some, according to theorists who support the Big Bounce theory, may be even older. Essentially, the Big Bounce theory proposes that our universe arose from the collapse of a previous universe. Of course, all traces of that universe would be destroyed—except, perhaps, black holes.
We know, for example, that supermassive black holes (with masses ranging from 1 million to 10 billion times that of our Sun) existed much earlier than their sizes would suggest. There simply wasn't enough time for the birth and death of the first stars, or for the remaining black holes (with masses only a few times that of the Sun) to reach supermassive size.
It is also believed that during the collapse preceding the Big Bounce, black holes would not have merged with the densely packed matter, but would have remained separated as bubbles—albeit much smaller than they actually were. Therefore, some believe that the incredibly supermassive black holes in our universe could have originated from black holes in a pre-existing universe.
Other articles that may interest you