How was the earth created?

There are a couple of theories of planetary formation. The most commonly accepted one is that the same inter-stellar materials that coalesced into stars also formed the planets that orbit the stars.

Specific planetary rock/element ratios indicate that the planets are probably formed from other materials ejected from expiring stars (novas). These can become trapped in orbits around other stars, and then gravitationally accrete to form the larger bodies.

Moons are smaller bodies that are held by the planets in their own orbits.

The formation of Earth is a process that occurred approximately 4.5 billion years ago, stemming from the solar nebula, a giant, rotating cloud of gas and dust in space. This nebula collapsed under its own gravity, leading to the formation of the Sun at its center. Surrounding the young Sun, the remaining material began to flatten and form a protoplanetary disk.

Within this disk, particles of dust and rock collided and stuck together, gradually forming larger bodies called planetesimals. Over time, these planetesimals accreted into even larger bodies, eventually forming the early planets, including Earth.

Initially, Earth was molten due to frequent collisions with other bodies, which also contributed to its growth. This molten state allowed for the differentiation of the Earth's layers, with denser materials sinking to form the core and lighter materials forming the mantle and crust.

The Earth's early atmosphere likely formed from volcanic outgassing, releasing gases trapped within the Earth. Water vapor in this early atmosphere condensed to form the oceans, once the Earth had cooled enough for liquid water to exist.

This brief overview simplifies a complex process that involves numerous stages and influences, including the impact of large celestial bodies, which notably includes the giant impact hypothesis for the formation of the Moon. This theory suggests that a Mars-sized body collided with the early Earth, ejecting material that eventually coalesced to form the Moon, which also had significant effects on Earth's development.