A Brief History of the Formation of the Earth

Why do we live on Earth? The answer might be: "Because we are suitable for it." But wait a minute. We, advanced primates, did we chose this planet ourselves?
Blue Planet Earth

Our Blue Planet - shutterstock

Of course no!

We have evolved on Earth as the most advanced form of intelligence. The Earth has conditions that allow a life form to evolve. However, these conditions are not preconfigured. These conditions depend on the changing dynamics of the Earth which developed during Earth’s evolution in the Solar System and accordingly its changing physical constants.

We now have a great deal of knowledge about our Earth and its history, evolution, and development. There is a lot of information about the evolution of the Earth. In addition, our knowledge has shed light on important issues such as the evolution of life. Now, let’s start with the evolution of Earth and get to know the planet we live on.

Evolutionary History of the Earth

What comes to your mind when you hear the word “evolution”? Evolution, besides its biological meaning, is actually an astronomical and physical term. Many changes such as the energy circulation in the universe, transitions between matter and energy, expansion of the universe and systems that adapt to these changes, show us that another evolution continues in a universal sense. And the evolution of our planet is an important part of this constant evolution for us.

We can predict the formation of our Earth is closely related to the formation and evolution of the Sun. As a matter of fact, all sources refer to a cloud of gas and dust that is hot and spinning in order to explain the formation of any star or planet. But how can a spinning cloud turn into a solid planet or hot star?

According to a theory, these dust and gas clouds became increasingly dense as they spin around a center. The dust clouds which formed the Sun, have been able to initiate fusion reactions in the center of the Sun, because they were spinning with enough pressure. But the pressure of the dust clouds which formed the planets was not enough.

While the Earth was still hot and dynamic, it began to revolve around the Sun because of the pull of the Sun’s gravity. The Earth and the other planetary formations, which are increasingly colliding with other things, grew larger and larger and as a result, they all reached to their today’s sizes.

We don’t know exactly when the Earth was formed in these gas and dust clouds. But, the age of the oldest rock on Earth is 4.28 billion years. In addition, the oldest minerals discovered in Australia are zirconium minerals and they are 4.36 billion years old. Scientists think that the Earth is 4.5 to 4.6 billion years old.

When our Earth was first formed, its surface temperature was about 1100ºC at that time and there was no oxygen. There were only carbon dioxide, water vapor and nitrogen. Our newborn planet was boiling with liquid rocks. While various rock fragments fall in the form of meteors a young planet named Theia approached our Earth.

Theia - Earth Collision

Art by Dana Berry – Soruce: Robin Canup, Swri

Inevitably, a collision has occurred. Scientists call this collision Great Impact Hypothesis. Trillions of pieces of Earth and Theia after collision turn into the hot dust and rock ring surrounding our Earth with the effect of mass gravity. What do you think, what will this rock ring form? Yes, The Moon.

At that time, the Earth is full of hot rocks on the surface. 1 day is 6 hours. Because our Earth spins so fast. Although the days pass fast, our Earth changes slowly.

Let’s go forward millions of years. The remaining parts of the solar system are falling on our planet. This is a very long process. The fragments that fall in the Earth carry particles that resemble salt crystals.

These crystal-like particles carry water droplets to our planet. Each piece of meteor, contains unvaporized water because they were away from the Sun. But in small quantities. In addition, meteorites may also contain the elements necessary for life.

After 20 million years of meteor shower the Earth becomes abundant with water. Now, the Earth looks more familiar. But the air temperature is about 200ºC, and the winds blow even faster than the strongest hurricanes of today. The Earth is still a deadly place.

Because the Moon is close to the Earth, great tides occur. But over time the Moon begins to move away, the tides and sea waves decrease. The Earth slows down. Now, 3.8 billion years ago, the islands formed by water and rocks are scattered on the surface of the Earth.

The molten rock bursts through the crust of our Earth and ascends along the ocean. The sprayed lava cools, and volcanic islands are formed.

Yes, now our planet has water and land. This is very important for the evolution of the life. But the atmosphere is full of toxic and, the weather is very hot. The evolution of the life seems impossible yet. And what is this? A new attack: Meteor attack!

Meteor Shower

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3.8 billion years ago. This time the meteorites carry other materials along with water. Because most of the surface area is oceans, meteors usually fall into the oceans, and they release minerals. These minerals, composed of carbon and proteins, have reached the Earth from the depths of space. The oceanic minerals are encountering a very cold environment here, thousands of feet deep. Another surprise: Underwater volcanoes. They release hot liquids. Sea water leaks into the inner layer of the Earth, cracks the shell and collects minerals. The compound of minerals and meteorites is now a primordial soup.

Maybe after billions of attempts, collision took place between the right molecules and with the right energy. The first form of life on the Earth began.

3.5 billion years ago. Plant-like creatures are now available for observation. They have a very important feature: they can produce food with photosynthesis using rays from the Sun, and they release oxygen. Underwater stromatolites slowly fill the ocean with oxygen.

Even after 3 billion years from the formation of our planet, complex life forms are not found. A planet where plants, dinosaurs, and humans don’t exist. But the Earth has something that is not found on the other planets. Something that can change everything: plate tectonics. The rocks below the ocean floor are moved by the very hot core. The continents unite and leave. After a period of 400 million years, there is a super continent in the ocean: Rodinia.

Shallow waters are beginning to envelop Rodinia. The temperature is 85ºC at this stage. At this stage, our Earth is like the Mars of our day. We are looking for life. We can’t find. We need to go 750 million years forward. At this stage, the heat released from the depths of our Earth weakens the surface layer, and the Great Continent, Rodinia, begins broke it apart.

Strong geological activity reveals volcanoes, and they are pumping carbon dioxide into the atmosphere. Carbon dioxide is returned to the Earth as acid rain and is absorbed by rocks on Earth. Absorption of carbon dioxide into the Earth is very high. For this reason, there is now nothing to keep the sun’s lights and heat on earth. In a few thousand years, the temperature is -60ºC.

Snowball Earth

When Earth was a frozen snowball – Alamy

650 million years ago. The period that scientists call “Snowball Earth”. This period is thought to be the longest ice age that our Earth has ever experienced. The ice on the earth reflects more of the sun’s rays, so there is a faster spread of ice. Now an ice layer of 3000 meters in thickness. Look at this. Earth, which is a ball of fire once, is now a snowball!

Volcanoes have been erupting since the Earth began to cool down.

But because the surface has been covered with ice, there is nothing that can absorb the gas. So these gasses fill the atmosphere. Carbon dioxide keeps the sun’s rays in our Earth, allowing the temperature to rise again. Now, after 15 million years, the ice is starting to melt. As the ice melts, the Earth’s crust strata burst out, and new volcanoes appear from weak spots. Now the Earth is awakening. 600 million years ago, our atmosphere is now warmer. Days last 22 hours.

Before the Snowball Earth, we know that primitive bacteria evolved in the oceans. But of course, they couldn’t stand the ice process, which is 80 times more from the history of human.

540 million years ago, in the oxygen-filled ocean, primitive bacteria started to evolve again. Bacterial colonies and some primitive creatures can be observed on the ocean floor. At this very moment, our Earth is entering the most dynamic period of its history: the Cambrian Explosion.

The increased oxygen rate allows the evolution of more complex organisms: insects, lobster-like creatures, and even trilobites that are remote-related to scorpions.

Life in the ocean gets varied.