Earth. Characteristics and simulations

15/04/2026

The online simulations of the Earth on this page will allow you to deepen your knowledge of our planet. We will discover its most outstanding features, its shape and size, its composition and its most outstanding motions

This Thematic Unit is part of our Earth Sciences collection

Core

Center of the Earth, made of iron and nickel, divided into outer and inner.

Earth

Third planet from the Solar System, the only one with confirmed life and surface liquid water.

Earth’s Crust

Outermost and thinnest layer of the Earth, composed of solid rocks.

Geoid

Theoretical shape of the Earth equivalent to the mean sea level extended through the continents.

Lunar Eclipse

Event where the Earth comes between the Sun and the Moon, casting its shadow on it.

Mantle

Intermediate layer of the Earth located between the crust and the core.

Nutation

Small periodic oscillation of the Earth’s axis combined with precession.

Penumbra

Region of partial shadow surrounding the umbra during an eclipse.

Precession

Slow and gradual change in the orientation of Earth’s rotational axis.

Rotation

Earth’s movement on its own axis that results in day and night.

Translation

Earth’s movement around the Sun that determines the length of the year.

Umbra

Darkest and central part of the shadow cast during an eclipse.

What is the Earth

Earth is our home, a beautiful and diverse planet. It is the third planet from the Sun in our solar system and is composed of a unique combination of elements and conditions that allow the existence of life as we know it.

Characteristics of the Earth

It is the densest and fifth largest of the eight planets in the solar system. It is also the largest of the four terrestrial or rocky planets. Earth is home to an astonishing diversity of ecosystems and living things, from microorganisms to animals and plants. In addition to terrestrial life, the oceans are home to a variety of marine creatures, from tiny fish to majestic whales and fascinating coral reefs.

Shape and size of the Earth

The shape of the Earth is described as a geoid, meaning that it has a shape similar to a sphere that is slightly flattened at the poles and widened at the equator. This is due to the effect of the Earth’s rotation, which generates a slight bulge at the equator due to centrifugal force. The equatorial radius is 6,378 kilometers (3,963 miles) while the polar radius is 6,357 kilometers (3,950 miles).

Composition of the Earth

The Earth’s surface is mostly (71%) covered by oceans of water. The remainder is made up of continents and islands. The Earth’s poles are mostly covered with solid ice. No other planet is known with this amount of liquid water, which is indispensable for any known type of life. The interior of the planet is geologically active, with a thick layer of relatively solid mantle, a liquid outer core that generates a magnetic field, and a solid inner core composed of about 88 % iron. The Earth is covered by a layer of air called the atmosphere, which protects and maintains conditions suitable for life. This atmosphere is composed mainly of nitrogen and oxygen.

Motions of the Earth

The Earth performs several motions, the most important of which are rotation and translation.

Rotational motion

The Earth rotates on its imaginary axis in a west-to-east motion. This complete rotational motion is carried out in approximately 24 hours, resulting in the succession of days and nights. The Earth’s rotation is responsible for the daily cycle of the sun and for the patterns of light and dark in different regions of the planet.

Translational motion

The Earth performs a translational motion around the Sun. It takes approximately 365.25 days (one year) to complete one orbit around the Sun. This translational motion is responsible for the seasons of the year. As the Earth moves around the Sun.

Other motions of the Earth

Other motions of the Earth are precession, nutation, Chandler’s wobble and perihelion precession.

These online simulations of the Earth help to improve our knowledge about our home in the universe – make the most of them!

Core

Center of the Earth, made of iron and nickel, divided into outer and inner.

Earth

Third planet from the Solar System, the only one with confirmed life and surface liquid water.

Earth’s Crust

Outermost and thinnest layer of the Earth, composed of solid rocks.

Geoid

Theoretical shape of the Earth equivalent to the mean sea level extended through the continents.

Lunar Eclipse

Event where the Earth comes between the Sun and the Moon, casting its shadow on it.

Mantle

Intermediate layer of the Earth located between the crust and the core.

Nutation

Small periodic oscillation of the Earth’s axis combined with precession.

Penumbra

Region of partial shadow surrounding the umbra during an eclipse.

Precession

Slow and gradual change in the orientation of Earth’s rotational axis.

Rotation

Earth’s movement on its own axis that results in day and night.

Translation

Earth’s movement around the Sun that determines the length of the year.

Umbra

Darkest and central part of the shadow cast during an eclipse.

Explore the exciting STEM world with our free, online, simulations and accompanying companion courses! With them you’ll be able to experience and learn hands-on. Take this opportunity to immerse yourself in virtual experiences while advancing your education – awaken your scientific curiosity and discover all that the STEM world has to offer!

Simulations of the Earth

Eratosthenes
Foucault
Eclipses

Calculating the circumference of the Earth by Eratosthenes

The first person to measure the size of the Earth was Eratosthenes, an ancient Greek scientist about 2,000 years ago. From basic geometry and the shadow of a tower he calculated the circumference of the Earth to be about 46,000 km. This value is slightly larger than the value measured today of about 40,000 km.

Foucault’s pendulum

Foucault’s pendulum is a device invented by the French scientist Leon Foucault to test the Earth’s rotation.

Eclipses

An eclipse is the phenomenon by which one object occults another or enters into its shadow. A solar eclipse is the phenomenon of the moon covering the sun. A lunar eclipse occurs when the moon enters the earth’s shadow..

Giants of science

“If I have seen further, it is by standing on the shoulders of giants”

Isaac Newton

Edwin Powell Hubble

1889

–

1953

Edwin Hubble demonstrated the expansion of the universe and classified galaxies, establishing the foundations of modern observational cosmology

“Equipped with his five senses, man explores the universe”

Nicolaus Copernicus

1473

–

1543

Nicolaus Copernicus revolutionized astronomy by placing the Sun at the center of the planetary system; he provided precise mathematical observations.

“The Sun, not the Earth, is the center of our planetary system”

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Giants of science

“If I have seen further, it is by standing on the shoulders of giants”

Isaac Newton

1643

–

1727

Isaac Newton formulated the law of universal gravitation and the three laws of motion, founding classical mechanics.

“If I have seen further, it is by standing on the shoulders of giants”

Johannes Kepler

1571

–

1630

Kepler formulated the three laws of planetary motion, establishing elliptical orbits and the relationship between planetary period and distance from the Sun

“The heavens teach the geometry that nature follows”

Become a giant

Your path to becoming a giant of knowledge begins with these top free courses

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The Radio Sky II: Observational Radio Astronomy

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The Radio Sky I: Science and Observations

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Our Place in the Universe

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Our Global Ocean – An Introduction Course

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Sensing Planet Earth – Water and Ice

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The History of Ancient Environments, Climate, and Life

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Sensing Planet Earth – From Core to Outer Space

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Test your knowledge

What is the Earth and what are its main characteristics?

The Earth is the third planet from the Sun and has an almost spherical shape, slightly flattened at the poles. Its surface is covered by continents and oceans, and it is surrounded by an atmosphere that allows life and regulates temperature. Its size and composition make liquid water possible and create stable conditions for living beings, making it a unique planet within the solar system.

What are the movements of the Earth and how do they affect daily life?

The Earth mainly has two movements: rotation on its axis, which lasts approximately 24 hours and causes the cycle of day and night, and revolution around the Sun, which lasts one year and results in the seasons. The tilt of the Earth’s axis means that different hemispheres receive varying amounts of sunlight throughout the year, producing changes in light and temperature that affect natural cycles and daily life.

How is it that we don’t feel the Earth spinning even though we have day and night every day?

Even though we don’t directly feel the Earth’s rotation, we experience sunrise and sunset every day because of this constant movement. It’s interesting to realize that we are in continuous motion and that our entire experience of day and night depends on a spin we can’t sense.

Why do the seasons change if the distance to the Sun doesn’t vary much?

The seasons change because of the tilt of the Earth’s axis, not the distance to the Sun. This tilt makes different parts of the planet receive more or less sunlight at different times of the year, creating summer, winter, spring, and autumn, even though the distance to the Sun remains almost constant.

Does it make sense that the Earth has more movements besides rotation and revolution?

Yes, because in addition to rotation and revolution, the Earth has other subtler movements that affect its orientation and position over long periods. These movements are not noticeable in daily life, but they show that the planet’s dynamics are more complex than they appear at first glance.