Formation of the Earth and Moon

Formation of the Earth and Moon

This animation demonstrates how the Earth and the Moon were formed.

Geography

Keywords

Earth, Moon, formation of the Earth, formation of the Moon, Solar System, proto-Earth, Theia, planet, protoplanet, rocky planet, terrestrial planet, Earth globe, astronomy, astrophysics, geography, physics, physical

Related items

Scenes

The formation of the Earth is related to the formation of the Solar System. The gases forming the Solar System started gradually shrinking. Increasingly more matter gathered in the center while temperature was constantly increasing. The Sun formed from this condensed molecular cloud of dust. Due to rapid rotation, the rest of the cloud scattered and flattened into an orbiting protoplanetary disk around the Sun. The dust in the protoplanetary disk stuck together electrostatically, and when they reached kilometers in size, they began to collapse under their own gravity, forming protoplanets. This is also how Earth was formed 4.6 billion years ago.

Around 170 million years after the formation of the Earth, a young planet known as Theia struck the Earth’s still soft crust. Theia was demolished after the collision and its matter merged with Earth. Earth’s mass therefore increased, effectively reaching its current mass. The impact created a large debris ring around Earth.

The Moon formed out of this debris ring. After the dissolution of the ring, the Moon became a hot glowing celestial body orbiting 25,000 kilometers (15,530 miles) above the Earth’s surface. During this period, the Moon still had volcanoes, lava flows and its own magnetic field.

The tidal phenomenon occurring between Earth and the Moon led to various changes. Firstly, the Moon became tidally locked with Earth, meaning it takes just as long to rotate around its own axis as it does to revolve around Earth. Secondly, the Moon gradually receded from Earth, cooled down and then became geologically inactive.

Currently, the average distance of the Moon from Earth is 384,000 kilometers (238,600 miles). Even to this day, it is receding from Earth (3.8 cm or 1.5 in annually). As a result, it takes the Moon increasingly more time to revolve around Earth, however, due to tidal locking, the period it takes to rotate around its own axis is also increasing. The tidal phenomenon also affects Earth; Earth’s rotation period is decreasing, meaning the length of the Earth’s day is slowly increasing.

Definitions:

Planet: an astronomical object orbiting a star (e.g. the Sun) that is not massive enough to cause thermonuclear fusion (therefore it is not luminous), but massive enough to be rounded by its own gravity.

Star: a luminous sphere of plasma, shining due to the various fusion reactions that take place inside its core.

Solar System: the Sun dominates the Solar System gravitationally. The system is a sphere approximately 2 light-years in radius. Numerous small bodies orbit the center of it, the Sun.

Narration

The formation of the Earth is related to the formation of the Solar System. The gases that form the Solar System gradually started shrinking. Increasingly more matter gathered in the center while temperature was constantly increasing. The Sun formed from this condensed molecular cloud of dust. Due to rapid rotation, the rest of the cloud scattered and flattened into an orbiting protoplanetary disk around the Sun. The particles of dust in the protoplanetary disk stuck together electrostatically, and when these clumps of dust reached kilometers in size, they began to collapse under their own gravity, forming protoplanets. This is also how the Earth formed 4.6 billion years ago.

Around 170 million years after the formation of the Earth, a young planet known as Theia struck the Earth’s still soft crust. Theia was demolished after the collision and it merged with the Earth. The Earth’s mass therefore increased, effectively reaching its current mass. The impact created a large ring of debris around the Earth, which later formed into the Moon.

After the dissolution of the ring, the Moon became a glowing hot celestial body orbiting 25,000 kilometers (15,530 miles) above the Earth. During this period, the Moon still had volcanoes, lava flows and its own magnetic field.

The tidal phenomenon that occurs between the Earth and the Moon led to various changes. Firstly, the Moon became tidally locked with the Earth, meaning it takes the Moon just as long to rotate around its own axis as it does to revolve around the Earth. Secondly, the Moon gradually receded from the Earth, cooled down and then became geologically inactive.

Currently, the average distance of the Moon from the Earth is 384,000 kilometers (238,600 miles). Even to this day, it is receding from the Earth (3.8 cm or 1.5 in a year). As a result, it takes the Moon increasingly more time to revolve around the Earth; however, due to tidal locking, the period it takes to rotate around its own axis is also increasing. The tidal phenomenon also affects the Earth; the Earth’s rotation period is decreasing, meaning the length of the Earth’s day is slowly increasing.

Related items

Change of seasons (basic)

Due to the Earth´s tilted axis, the angle of the Sun's rays at given latitudes is continuously changing during the year.

Change of seasons (intermediate)

Due to the Earth´s tilted axis, the angle of the Sun's rays at given latitudes continuously changes during the year.

Comets

Comets are spectacular celestial bodies orbiting the Sun.

Continental drift on a geological timescale

The Earth's continents have been in constant motion during the history of the planet.

Continents and oceans

Dry land on the surface of Earth is divided into continents which are separated by oceans.

Earth

The Earth is a rocky planet with a solid crust and oxygen in its atmosphere.

Interesting astronomy facts

This animation presents some interesting facts in the field of astronomy.

Lunar eclipse

Lunar eclipses occur when the Moon passes through the shadow cone of Earth

Moon landing: July 20, 1969

Neil Armstrong, one of the crew members of Apollo 11 was the first man to set foot on the Moon.

Moon radar experiment (Zoltán Bay, 1946)

In 1946 a Hungarian scientist was the first person to detect radar echoes from the Moon.

Phases of the Moon

During its orbit around the Earth, the visibility of the Moon's illuminated part constantly changes.

Solar eclipse

When the Sun, Earth, and the Moon are arranged in a straight line, the Moon can partially or completely obscure the Sun.

Structure of Earth (elementary)

The Earth is composed of several spherical layers.

Structure of the Earth (intermediate)

The Earth is composed of several spherical layers.

The Dawn mission

Studying Ceres and Vesta will help us learn more about the early history of the Solar System and how rocky planets are formed.

The Earth’s magnetic field

The Earth’s magnetic North and South poles are located near the geographic North and South poles.

The Moon

The Moon is the Earth's only natural satellite

The Sun

The diameter of the Sun is about 109 times that of the Earth. Most of its mass consists of hydrogen.

Tide

The rise and drop of sea levels caused by the gravitational force of the Moon.

Timeline spiral

Place historical events on the time spiral.

Apollo 15 mission (Lunar Rover)

The animation shows the two-seater Lunar Rover used in the Apollo 15 mission

Added to your cart.