Planets of the Solar System

15/04/2026

The solar system planetary simulations online on this page will allow you to deepen your knowledge about the planetary system in which the Earth is located. You will learn about the inner and outer planets and you will visualize the characteristics of the motion of some of them.

This Thematic Unit is part of our Earth Sciences collection

Albedo

Proportion of sunlight that a planetary surface reflects back into space.

Earth

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

Eccentricity

Measure of how much a planet’s orbit deviates from being a perfect circle.

Jupiter

The largest planet in the Solar System, a gas giant composed mainly of hydrogen and helium.

Mars

Fourth planet, called the Red Planet due to the iron oxide on its surface.

Neptune

The planet farthest from the Sun, an ice giant with the strongest winds in the Solar System.

Orbital Period

Time it takes for a planet to complete one full revolution around the Sun.

Rotation Period

Time it takes for a planet to rotate once on its own axis.

Saturn

Gas giant famous for its extensive and bright ring system.

Uranus

Ice giant with a highly tilted rotation axis, almost parallel to its orbit.

Venus

Second planet in the Solar System, known for its dense carbon dioxide atmosphere and high temperatures.

The planets of the solar system

The solar system is a planetary system composed of eight main planets: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. Each planet has unique characteristics that distinguish them and make them fascinating.

Inner planets of the solar system

The inner planets of the solar system, also known as terrestrial or rocky planets, are the planets that are closest to the Sun. They have a rocky composition and are relatively small in size compared to the outer planets.

Mercury. It is the closest planet to the Sun and also the smallest. It has a rocky surface and is riddled with craters caused by asteroid and comet impacts.

Venus. It is known as Earth’s “sister planet” because of its similar size, but it is extremely inhospitable. Its dense atmosphere is composed mainly of carbon dioxide and has a scorching surface temperature.

Earth. It is our home and the only planet known so far to have life. It has a great diversity of landscapes, from mountains and oceans to deserts and jungles.

Mars. Also called the “red planet,” it has captured our imagination because of its similarity to Earth and the possibility of having harbored life in the past.

Outer planets of the solar system

The outer planets of the solar system, also known as giant or gas planets, are farther from the Sun and have distinctive characteristics compared to the inner planets.

Jupiter. It is the giant of the solar system and the largest planet. It is composed mainly of gas and has an impressive storm called the Great Red Spot.

Saturn. It is famous for its beautiful rings, which are composed of ice and rock particles.

Uranus and Neptune. They are gas giants with turbulent atmospheres and have distinctive features, such as the strongest winds in the solar system on Neptune.

Galilean satellites and other objects in the solar system

In addition to these planets, the solar system also harbors other fascinating objects.

The Galilean satellites, discovered by Galileo Galilei in 1610, are the four largest satellites of Jupiter: Io, Europa, Ganymede and Callisto. These celestial bodies stand out for their unique characteristics and their relevance in astronomy. Io is the most volcanically active object in the solar system, with more than 400 active volcanoes. Europa, with its icy surface, is a prime candidate for the search for extraterrestrial life due to the possibility of having a subsurface ocean. Ganymede is the largest satellite in the solar system, even larger than the planet Mercury, and has its own magnetic field. Callisto, on the other hand, presents a surface full of craters and it is believed that it could also have an ocean under its crust.

Pluto, although no longer officially considered a planet, is an icy dwarf object orbiting beyond Neptune. There are also asteroids, comets, and small bodies known as dwarf planets, such as Ceres and Eris, scattered throughout the solar system.

Exploring the planets of the solar system

These planets and celestial objects have been explored in detail by space missions, such as those of NASA, ESA and other international space agencies. As we continue to research and learn about the solar system, more secrets and wonders are revealed that allow us to better understand our place in the universe.

Albedo

Proportion of sunlight that a planetary surface reflects back into space.

Earth

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

Eccentricity

Measure of how much a planet’s orbit deviates from being a perfect circle.

Jupiter

The largest planet in the Solar System, a gas giant composed mainly of hydrogen and helium.

Mars

Fourth planet, called the Red Planet due to the iron oxide on its surface.

Neptune

The planet farthest from the Sun, an ice giant with the strongest winds in the Solar System.

Orbital Period

Time it takes for a planet to complete one full revolution around the Sun.

Rotation Period

Time it takes for a planet to rotate once on its own axis.

Saturn

Gas giant famous for its extensive and bright ring system.

Uranus

Ice giant with a highly tilted rotation axis, almost parallel to its orbit.

Venus

Second planet in the Solar System, known for its dense carbon dioxide atmosphere and high temperatures.

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 planets of the solar system

Inner
Venus
Mars
Júpiter

Inner planets of the solar system

In this first one of the online solar system planet simulations, you can see the motion of Mercury, Venus and the Earth along their orbits around the Sun. Observe how, due to their different translation speeds, the distances between the planets and the angular position of Mercury and Venus with respect to the Earth change.

Apparent motion of Venus

In this animation you can see the apparent motion of Venus as seen from the Earth.

Apparent motion of Mars

See what the motion of Mars is like with respect to the Earth and how it approaches or moves away, due to the different translation velocities of Mars and the Earth.

Galilean moons

In this last of the online solar system planet simulations, the motion of the Galilean moons, the four largest of those orbiting Jupiter: Io, Europa, Ganymede and Callisto, is depicted.

Giants of science

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

Isaac Newton

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”

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”

Become a giant

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Giants of science

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

Isaac Newton

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”

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”

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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Introduction to Deep Earth Science

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The History of Ancient Environments, Climate, and Life

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Test your knowledge

What criteria are used to classify the planets of the solar system, and what does this classification reveal about their origin and composition?

The planets of the solar system are mainly classified into inner or rocky planets—Mercury, Venus, Earth and Mars—and outer or giant planets—Jupiter, Saturn, Uranus and Neptune. This division reflects clear differences in composition, size and distance from the Sun. The inner planets are small, dense and made of solid materials such as iron and silicates, while the outer planets are much larger and composed mostly of gases or ices. This classification reveals that the solar system formed from a protoplanetary disk where temperature decreased with distance from the Sun: close to it, only heavy materials could condense, whereas farther away, lighter gases and volatile compounds accumulated. The current distribution of planets is therefore not random but a direct consequence of the physical conditions present during the formation of the solar system.

How does each planet contribute to our overall understanding of the solar system’s dynamics and evolution?

Each planet provides essential clues about the history and evolution of the solar system. Rocky planets help us study processes such as atmospheric formation, geological activity and the presence of water in the past. Mars, for example, offers evidence of ancient climates and potentially habitable conditions. Gas giants like Jupiter and Saturn reveal how mass was distributed in the early solar system and how their strong gravity shaped the movement of asteroids and comets. Uranus and Neptune, classified as ice giants, show the role of compounds such as methane and ammonia in colder regions far from the Sun. Together, the planets act as layers of information that allow scientists to reconstruct how the solar system formed, how it changed over time and why its components are arranged as they are today.

Why are the planets so far apart from each other?

Because the solar system formed from a cloud of gas and dust that spread out as it rotated around the Sun. Planets formed only in regions where enough material gathered, leaving huge gaps between them. Later, the gravity of the giant planets pushed many objects outward, increasing the distances even more. Their spacing isn’t random—it reflects how matter was distributed when the solar system was born.

Why do some planets have rings while others don’t?

Rings are made of ice, dust and rock fragments trapped by a planet’s gravity. Gas giants like Saturn or Jupiter have much more mass, so they can hold large amounts of material around them. Rocky planets are too small to maintain such structures. It’s not that they couldn’t have rings, but they don’t have enough gravitational pull to keep them stable.

Why don’t planets crash into each other if they’re all moving?

Because each planet follows a stable orbit around the Sun. These orbits are well separated and don’t cross. The Sun’s gravity keeps every planet in its path, preventing them from drifting too close to one another. Even though they move very fast, they do so in an orderly and predictable way, which is why collisions don’t happen.