Rocky, icy or gaseous? Learn everything about the 8 planets of the Solar System

Our Solar system It is formed by eight planetsfour of them rocky, with solid surfaces — Mercury, Venus, Earth and Mars –, two gas giants — Jupiter and Saturn — and two ice giants — Uranus and Neptune.

In addition to these, thousands have been discovered and continue to be discovered every day outside our System, the so-called exoplanets. Learn more about each of the planets in the Solar System in order of proximity to the Sun below.

Mercury

It is the smallest planet in the Solar System — just a little larger than our Moon and about a third the size of Earth. Mercury is closest to the Sun, so much so that sunlight takes just 3.2 minutes to reach its surface.

During the day, its temperatures reach 430°C, but it is not considered the hottest in the Solar System, as it belongs to Venus. Due to its heat and solar radiation, Mercury is a planet to which organisms are unlikely to adapt.

Mercury’s craters are named after famous deceased artists, musicians, or authors. Some are: Bach, Beethoven, Cervantes, Hemingway, Michelangelo, Neruda, Picasso and the Brazilians [José de Alencar] It is [Tarsila do] Amaral.

Venus

Nicknamed Earth’s “evil twin”, similar in structure and size. Its diameter is 12,104 kilometers, while that of our planet is 12,756 kilometers.

Its atmosphere, however, is very different from our planet. It is so dense that it retains enough heat to melt lead on its surface — making it the hottest in the Solar System, second only to the Sun itself. Just about 50 kilometers above the surface is an environment that allows terrestrial life, with temperatures ranging from 30°C to 70°C.

The name Venus was a tribute to the ancient Roman goddess of love and beauty, known as Aphrodite to the ancient Greeks. The valleys, mountains and volcanoes on its surface are named after real and mythical women. An example is the crater called Sacagawea, named after the Native American woman who guided Lewis and Clark — the pair of explorers who led the first major exploratory expedition in North America — and a canyon called Diana in honor of the Roman goddess of hunting.

Earth

This is the only planet in our Solar System with liquid water, a substance that occupies 70% of its surface and allows the existence of life — the only one confirmed to date. It is estimated that its formation occurred 4.56 billion years ago and it is the only planet that has only one Moon.

The duration of its orbit around itself is 23.9 hours — one day — and around the Sun, 365.25 days — one year. The 0.25 that is “left over” is the reason for the existence of leap years, which serve to regulate the calendar. Sunlight takes approximately 8 minutes to reach the Earth’s surface.

The name of our planet is the only one that did not come from Greek or Roman. It is inspired by Old English and German, and means soil.

Mars

The planet is about half the size of Earth, making it the only one where humans have sent space vehicles to traverse the terrain. Mars has two moons in its orbit, Phobos and Deimos, and its rotation lasts 24.6 hours, a time similar to that of Earth.

There is water on Mars — which explains the efforts made to explore the planet —, however its atmosphere is so thin that the substance does not remain liquid for as long on the surface. Most are found below the polar regions and on some slopes and craters. Temperatures range from 20°C to -153°C and the rarefied atmosphere means heat escapes quickly.

The Romans named the planet Mars to honor their god of war, as the reddish color reminded them of blood, while the Greeks called it “the red one”. Today the nickname Red Planet continues, as the iron minerals in its atmosphere oxidize, giving the color to what we can see.

Mars has the largest volcano in the solar system, Olympus Mons, which is three times taller than Mount Everest, with a base the size of the state of Maranhão in Brazil.

Jupiter

This is the largest planet in our Solar System, a gas giant that was the first to be formed — from gases and dust left over from the formation of the Sun. It is 11 times larger than Earth and has a rotation of 10.5 hours, with the orbit around the Sun completed in 12 Earth years.

Jupiter does not have a rocky surface like Venus, Mars and Earth, and its pressure and the temperatures of its atmosphere are so extreme that if an aircraft tried to fly into the planet it would be crushed, melted and vaporized.

Its name is in honor of the king of the gods in Roman mythology, as it is the largest planet found in the Solar System. Jupiter has four large moons and countless smaller ones, 95 of which are recognized by the International Astronomical Union and named after mythological characters.

Saturn

The planet famous for its rings is nine times the size of Earth and was the furthest to be discovered with the naked eye from our surface. Its rotation takes 10.7 hours and its orbit around the Sun takes 29.4 Earth years.

Saturn was named after the Roman god of agriculture and wealth, father of Jupiter. Its rings are formed by pieces of comets, asteroids and moons that disintegrated before reaching the planet’s orbit. Some particles are pieces of ice, stones coated with other materials or dust — with sizes that can reach the size of mountains.

There are numerous moons orbiting Saturn, and as of June 2023, 146 have been recognized, with a queue awaiting official naming.

Uranus

Four times larger than Earth, the planet has a very cold climate and strong winds. Uranus was the first planet found using a telescope, discovered by astronomer William Herschel in 1781.

A day on Uranus takes about 17 hours and an orbit around the Sun takes 84 Earth years. The planet is made up solely of gases and has two sets of rings: an inner one, reddish in color, and the outer one, seen in bluish colors.

Its name came from the Greek god of the sky and its 28 moons are named after characters from the works of William Shakespeare and Alexander Pope. Two of them were named Oberon and Titania, inspired by the fairies from Shakespeare’s “A Midsummer Night’s Dream”, and Ariel and Umbriel, the sylphs from Pope’s “The Kidnapping of the Lock”.

Neptune

Also an ice giant, like Uranus, Neptune is the only planet in the Solar System that we cannot see with the naked eye due to its distance from Earth. It is 30 times further from the Sun than Earth, which contributes to its low temperatures.

Neptune is four times larger than Earth, has a 16-hour rotation and an orbit around the Sun of 165 Earth years. Most of the planet’s mass is made up of a dense fluid of materials such as water, methane and ammonia located above a small rocky core, making it the densest in our Solar System.

It was named after the Roman god of the sea, and its moons were named after several sea gods and nymphs from Greek mythology.