Origin of Planets

There are many unanswered questions in the universe. One of the most debated is the origin of planets. How did they form? What were the conditions like at that time? Is there life elsewhere in the universe? Scientists have been trying to answer these questions for centuries, and while we have made some progress, there is still much left to learn. In this blog post, we will explore the origins of planets and discuss what scientists know so far. 

Formation of the solar system

The solar system is formed when a huge cloud of dust and gas collapses under its own gravity. As the cloud collapses, it starts to spin faster and flatten into a disk. The disk has two parts: the inner part, where the sun and planets form, and the outer part, which is made up of leftover dust and gas.

As the disk flattens, it gets hotter in the middle where the sun is forming. The dust and gas start to clump together to form the planets. The inner part of the disk is too hot for water vapour, so the planets that form there are rocky: Venus, Earth, Mercury and Mars. The outer part of the disk is cooler, so the planets that form there are gassy: Jupiter, Saturn, Uranus, and Neptune. Pluto is a special case: it’s made of ice and rocks and is in the middle of the disk.

How did the earth form?

The planet, the earth, is made up of mainly four layers: the crust (first layer), the mantle (second layer), the outer core (third layer), and the inner core (fourth layer). All the layers have different compositions and play a unique role in the formation of the earth.

The crust is the outermost layer of the earth and is made up of solid rock. The mantle is the layer which is below the crust and is made up of hot, molten rock. The third layer i.e, the outer core layer is below the mantle and is made up of a liquid metal. The inner core is the layer below the outer core and is made up of solid metal.`

The earth formed about four and a half billion years ago when a cloud of gas and dust in the universe collapsed to form the sun. The earth formed from the leftover material that didn’t form the sun. This material was pulled together by gravity to form the earth.

As the earth formed, it was very hot and had no solid surface. The earth cooled over time and the solid crust formed. The first life on earth appeared in the oceans about three and a half billion years ago.

What happened during the earth’s dark age? (the first 500 million years)

It is said that during the formation of the earth, a planet called Mars collided with it. The impact of the collision caused the earth’s mantle to liquefy and form a magma ocean. The heat from the magma ocean vaporised the earth’s atmosphere. Over time, the earth cooled and the magma ocean solidified to form the crust.

The first 500 million years of earth’s history is called the Hadean aeon. It is named after Hades, the Greek god of the underworld because it was a time when the earth was a hot and hostile place. The surface of the earth was constantly bombarded by meteorites and comets.

Size and Distance of the planet earth

Earth is the biggest terrestrial planet and is also the fifth-biggest planet in the solar system. It has a diameter of 12,756 kilometres. Mercury is the closest to the sun, and it is the smallest planet. It has a diameter of just 4879 kilometres.

The earth is also the third farthest planet from the sun. It is 150 million kilometres from the sun, whereas Neptune is the farthest at just over four and a half billion kilometres away.

Orbit and Rotation of earth

Earth, orbits the sun and completes one rotation on its axis in 365.242 days or one sidereal year. This time period can be further divided into:

-A solar day is the length of time that the planet earth takes to complete one rotation with regard to the sun. It is defined as the time interval between two successive phases of the sun across the meridian of a place and is equal to 24 hours.

-A sidereal day is the time taken by the earth to complete one rotation on its axis with regard to the stars.

-A lunar day is the time taken by the earth to cover one rotation on its axis with regard to the moon.

Conclusion

In short, planets are born from the gravitational collapse of a molecular cloud. This process begins with the formation of clumps within the cloud. These clumps grow in size as they pull in more and more material from their surroundings. Eventually, the clumps become so large that they can no longer support their own weight and collapse under their own gravity. The collapsing clump forms a disk around its centre, which gradually becomes cleared of gas and dust until only a small central core remains. This core will eventually become the planet we see today. While there is still much to learn about planetary formation, this latest study provides us with a comprehensive guide to how planets are born.