The universe is infinite and constantly evolving. And how exactly did the familiar Earth and its solar system form?

The Earth and its solar system are the products of a complex and captivating cosmic evolution over billions of years. The dominant theory of the formation of the Earth and the solar system is the nebular hypothesis.

According to this hypothesis, about 4.6 billion years ago, a giant molecular cloud, known as the solar nebula, began to collapse under its gravity.

The collapse led to the formation of a spinning disk, with most of the matter collecting at the centre, forming the proto-sun or the young Sun.

Within the rotating disk of the solar nebula, tiny dust particles and gas began to collide and clump together through accretion.

These accumulations of matter, known as planetesimals, then collided and fused, gradually growing into protoplanets.

Over time, this process led to the formation of numerous protoplanets, including our Earth.

As the protoplanet that would become Earth continued to grow, gravitational forces and increased pressures caused it to differentiate into distinct layers.

Heavier elements sank toward the centre, forming a dense metallic core, while lighter elements rose to the surface, creating the crust. Between the core and crust, a layer known as the mantle formed, consisting of less dense rocks and minerals.

During the early stages of Earth's formation, a period known as the Late Heavy Bombardment occurred.

Intense and frequent impacts by asteroids, comets, and celestial bodies characterized this phase. These impacts delivered additional matter to the growing Earth and facilitated the distribution of water and organic compounds, providing the building blocks for life.

Another significant event in Earth's formation was the creation of the Moon.

According to the leading hypothesis, a Mars-sized object known as Theia collided with the young Earth approximately 4.5 billion years ago. This colossal impact resulted in the ejection of debris into space, which eventually merged to form the Moon.

This theory helps explain the similarities between the composition of Earth's mantle and Moon rocks obtained from lunar missions.

The solar system's formation involved a complex interplay of gravitational interactions between the planets. Over time, this led to a phenomenon known as planetary migration, where planets moved and settled into their present orbits.

Interactions with the remaining gas and planetesimals in the solar nebula facilitated this migration. Eventually, a stable configuration was achieved, resulting in the characteristic organization of our solar system.