History of the Earth in English PakWap

 See this structure? Looks scary and devoid of any possibility of life. But this is our home, the Earth at the beginning of its existence, . billion years ago! And its formation and the formation of the Moon remains a mystery. But today, we will tell you about the theories that scientists suggested.

Real History of the Earth

 You will learn how planets so different from each other form from the same material; what planet crashed into the Earth in the past; how much water there is on our planet, and where it came from. And finally, we will tell you how old the oldest organism on Earth is. 

We prepared the story of our planet, from a clump of dust and gas a few miles in diameter to the appearance of life. +[INTRO] When the Sun was created, gasses and other materials around it started colliding with each other and forming small bodies, called planetesimals. 

And as the gravitational forces were growing, more material was pulled together and these seeds of planets grew larger until they became true planets. The solar system’s gas giants, Jupiter and Saturn, Uranus and Neptune, were born much earlier than the four known terrestrial planets Mercury, 

Venus, Earth, and Mars. [][] But how exactly was our home planet born? +[Earth birth] The Earth’s story started about . billion years ago in a disk-shaped cloud of dust and gas rotating around the early Sun. And we know it was that long ago because of the fossil record - 

one of the most simple methods to determine the age of our planet. [][][] Scientists were able to find zircon crystals that are roughly . billion years old! So far, these crystals are the oldest materials found on our planet. [] But how exactly our planet was formed remains a scientific mystery.

 However, there are two leading theories on planetary formation. The core accretion model is the first one and most widely accepted. About . billion years ago, there was a solar nebula consisting of spinning gas and dust particles from which our Sun was born. 

Brief History of the Earth

Then, as the remaining material of different sizes orbited our star at slightly different speeds, it started to collide and stick together. Under the effect of gravity, smaller particles grew into larger particles that ranged from miles to hundreds of miles in diameter.

 The solar wind would then sweep away lighter elements, such as hydrogen and helium so that just rocky materials would stay closer and turn into terrestrial worlds. The process continues until these space objects reach thousands of miles in diameter. But far away from the star,

 the Sun's constant stream of charged particles doesn’t have a very strong impact on lighter elements. As a result, these elements combine and transform into gas giants. [][] What's exciting is that NASA believes that if this is the way planetary formation works, 

small, rocky worlds like the Earth are a lot more common throughout the universe than gas giants. The thing with this theory is that it works well to explain the formation of terrestrial planets but has problems explaining the creation of giant worlds. 

This is because scientists believe the gas disk around our Sun only lasted about - million years. And simulations based on the core accretion model show such planets form longer than that. [][] However, the second theory or the disk instability model resolves this issue.

 This newer idea suggests that chunks of dust and gas clump together early in the existence of the solar system. And, over time, these chunks slowly turn into a giant planet. But the difference is that this way, planets can form much faster than those explained by the core accretion model. In fact,

Extra History of the Earth

 according to this theory, it could happen within as little as , years! A planetary formation this fast makes it possible for such worlds to trap the rapidly vanishing lighter gasses. [][] A recent study suggests that proto-Earth was formed within about million years.

 And, on a cosmic scale, it’s nothing. If we converted the solar system’s estimated . billion years of existence into a -hour period, these million years would be equal to just about . minutes. [] If scientists are right about this, water could be just a by-product of the formation of a planet similar to our home.

 This would mean that we're a lot more likely to discover the ingredients for life outside our solar system. [] And what about our satellite? What’s the story of the Moon? +[Moon formation] Astronomers have proposed many hypotheses for the origin of our satellite. And some of them are quite bizarre.

 [] The Fission theory suggests that the Moon was once a part of our planet! When the Earth was still a hot ball of spinning lava it may have ejected the material our satellite is made of now. While most scientists remain skeptical because of how fast our planet must have been spinning

 to make this happen, it would’ve been a breathtaking phenomenon to observe! [] The Capture theory is yet another interesting idea suggesting that the Moon could’ve been captured from a different part of the solar system. We already know that some worlds have gained their moons in such a way. Perhaps, before it was attracted by our planet’s gravitational pull, the Moon was orbiting Venus. Still, this wouldn’t answer the question of why the Earth and the Moon have almost identical oxygen and isotope ratios. But the next theory could!