Name, Order, Features and Fun Facts

The Solar System is a planetary system consisting of the Sun at the center and the celestial bodies orbiting around it. The Solar System was formed from the collapse of a giant molecular cloud nearly 4.6 billion years ago. In the Solar System, there are a total of 8 planets, 5 dwarf planets, thousands of asteroids, comets and dust. In this article, we will learn about the names, order, characteristics and interesting things about the planets in the Solar System. Are you ready? Let’s get started!

Definition of planet

The International Astronomical Union (IAU) definition of a planet, adopted on August 24, 2006, includes the following three conditions:

• Orbit around a star.
• Has enough mass that its gravity causes it to form a sphere.
• Cleared the vicinity around its orbit.

The first condition excludes objects orbiting other stars, such as natural satellites and comets. The second condition excludes smaller objects, such as asteroids and comets. The third condition excludes even smaller objects, such as asteroids and comets, as well as gas giant planets, such as Jupiter and Saturn.

By this definition, the Solar System has eight planets:

• Mercury
• Venus
• Earth – along with its satellite the Moon
• Mars – along with its two moons, Deimos and Phobos
• Jupiter – with its 79 satellites
• Saturn – with its 82 satellites
• Uranus – with its 27 satellites
• Neptune – with its 14 moons

Jupiter and Mercury are opposite planets in mass. Jupiter is the largest planet in the Solar System, with a mass 318 times that of Earth. Mercury is the smallest planet in the Solar System, with a mass only 0.055 times that of Earth.

Pluto, once considered the ninth planet, is now classified as a dwarf planet. Dwarf planets are celestial bodies that have enough mass to form into a sphere, but not enough to clear out the neighborhood around their orbit.

The IAU definition has been widely accepted by astronomers, but there is still some controversy. Some scientists argue that the definition is too complicated and difficult to apply. Other scientists argue that the definition is not strict enough and can lead to incorrect classification of celestial objects.

Despite the controversy, the IAU definition is still the most commonly used today.

Number of planets in the solar system

The Solar System is a planetary system consisting of the Sun and the celestial bodies that orbit it. For centuries, astronomers believed that the Solar System contained nine planets, including Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. However, in 2006, the International Astronomical Union (IAU) adopted a new definition of a planet, according to which Pluto is no longer considered a planet and is now classified as a dwarf planet.

So, according to the IAU definition, the Solar System currently has 8 planets, including:

• Mercury
• Venus
• Earth
• Mars
• Jupiter
• Saturn
• Uranus
• Neptune

These planets are classified into two main groups:

• Terrestrial planets: Mercury, Venus, Earth, and Mars. These planets are composed mainly of rock and metal.
• Gas giant planets: Jupiter, Saturn, Uranus, and Neptune. These planets are composed mainly of gas and ice.

The number of planets in the Solar System is still a matter of debate. Some scientists believe that the IAU definition is too complicated and difficult to apply. Others believe that the definition is not strict enough and may lead to incorrect classification of celestial bodies.

In addition to the major planets, there are dwarf planets, which are spherical bodies that orbit the Sun but are not major planets because they cannot clear their orbital region of smaller objects. There are five dwarf planets recognized by the IAU: Ceres, Pluto, Haumea, Makemake and Eris. There are also many other unconfirmed dwarf planet candidates, such as Orcus, Quaoar, Sedna, Varuna and Vesta.

So, the number of planets in the Solar System could be eight, thirteen, or more, depending on how one defines a planet.

Order of Planets in the Solar System

According to the International Astronomical Union’s definition of a planet, in our solar system, there are eight major planets, in order from closest to farthest from the Sun: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune.

The order of the planets in the Solar System can be remembered with a simple verse, for example: “Water, Metal, Earth, Fire, Wood, Earth, Heavenly Sea” or “Water, Metal, Earth, Fire, Wood, Earth, Heavenly Sea”. These planets can be classified into two main groups: terrestrial planets and gas giants.

Terrestrial planets are small planets, composed mainly of rock and metal, and have few or no natural satellites. Terrestrial planets include Mercury, Venus, Earth, and Mars.

The gas giants are large planets composed primarily of gas, primarily helium and hydrogen, and have many natural satellites. The gas giants include Jupiter, Saturn, Uranus, and Neptune.

Interesting facts about the distance and order of planets in the solar system

• The distances between planets in the Solar System are very large. For example, the distance from Mercury to the Sun is about 58 million kilometers, while the distance from Neptune to the Sun is about 4.5 billion kilometers.
• The order of the planets in the Solar System is arranged from closest to farthest from the Sun. The planet closest to the Sun is Mercury, followed by Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune.
• Mercury is the smallest planet in the solar system, with a diameter only one-third that of Earth. Neptune is the largest planet in the solar system, with a diameter four times that of Earth.
• Mercury is the hottest planet in the solar system, with an average surface temperature of 427 degrees Celsius. Neptune is the coldest planet in the solar system, with an average surface temperature of only about -220 degrees Celsius.
• Jupiter is the planet with the strongest gravity in the Solar System. If a person stood on the surface of Jupiter, they would weigh 2.5 times more than they would on Earth.
• Saturn is a planet famous for its rings. Saturn’s rings are made up of billions of pieces of ice, rock, and dust.
• Uranus is a planet with an axis of rotation tilted at 98 degrees. This causes Uranus to have a season that lasts 21 Earth years.

Some other interesting facts:

• Jupiter could fit more than 1,300 Earths inside it.
• Saturn has 82 natural satellites, more than any other planet in the Solar System.
• Neptune has 14 natural satellites, the largest of which is Triton. Triton is Neptune’s largest natural satellite, with a diameter of 2,710 km (about 21% of Earth’s diameter). It is the seventh largest moon in the Solar System, and the only Neptune moon large enough to be in hydrostatic equilibrium.
• Pluto was once considered the ninth planet in the solar system, but is now classified as a dwarf planet.

Dwarf planets in the solar system

Dwarf planets are spherical bodies that orbit the Sun, but are not major planets, because they cannot clear their orbital region of smaller objects. Dwarf planets are smaller and less massive than major planets, and often have many natural satellites.

There are five dwarf planets recognized by the International Astronomical Union (IAU), namely: Ceres, Pluto, Haumea, Makemake and Eris. There are also many other unconfirmed dwarf planet candidates, such as Orcus, Quaoar, Sedna, Varuna and Vesta.

Characteristics of the planets

Planets in the solar system are large celestial bodies that orbit the Sun, the source of energy and light for the entire system. Planets can be classified according to various criteria, such as size, distance, composition, atmosphere, satellites, and life. Earth is the only planet in the solar system that has life because it has many favorable conditions for the development and maintenance of living organisms. Some important conditions are as follows:

• Earth is at the right distance from the Sun, not too close to melt or too far away to freeze. This distance ensures the right temperature for liquid water, a basic element for life.
• The Earth is protected from harmful solar radiation by a magnetic field and an ozone layer. The magnetic field prevents radiation particles from the sun and space from entering the atmosphere, while the ozone layer absorbs ultraviolet rays that can damage the DNA of living things.
• The Earth is kept warm by an insulating atmosphere, made up of gases such as nitrogen, oxygen, carbon dioxide, and water vapor. The atmosphere helps maintain a stable temperature at the surface, creates weather and climate phenomena, and provides oxygen for living things to breathe.
• The Earth has the right chemical composition for life, including water and carbon. Water is an important solvent for life’s chemical reactions, as well as a medium for aquatic organisms. Carbon is the basic element for organic compounds, such as sugars, proteins, lipids, and DNA, which are the structural and functional components of living things.

These are some of the reasons why Earth is the only planet in the solar system that has life. However, scientists are still studying the possibility of life on other planets, such as Mars, Mercury, or the satellites of the gas planets.

Here are some common characteristics of planets in the solar system:

Based on size, planets can be divided into two groups: terrestrial planets and gaseous planets. Terrestrial planets are those that are smaller, have solid surfaces, and have little or no atmosphere. Terrestrial planets include Mercury, Venus, Earth, and Mars. Gaseous planets are those that are larger, have irregular surfaces, and have dense atmospheres. Gaseous planets include Jupiter, Saturn, Uranus, and Neptune.

According to distance, the planets can be arranged in order from closest to farthest from the Sun as follows: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto. The distance of the planets from the Sun affects their temperature, brightness, and orbital period. The closer the planets are to the Sun, the hotter, brighter, and have shorter orbital periods. Conversely, the farther the planets are from the Sun, the colder, darker, and have longer orbital periods. In the solar system, the distance of the planets from the Sun is usually measured in astronomical units (AU). An astronomical unit is a unit of length, approximately equal to the average distance from the Earth to the Sun. If you want to know more details, you can refer to the article on how many kilometers is the distance from the Earth to the Sun?

Compositionally, planets can be distinguished by the ratio of chemical elements in their structure. Terrestrial planets are mainly made up of elements such as iron, magnesium, aluminum, silicon, oxygen, and carbon. Gaseous planets are mainly made up of elements such as hydrogen, helium, nitrogen, and methane. Planets can also have different components in their atmospheres, such as water, carbon dioxide, ozone, or ammonia.

According to their atmospheres , planets can be classified according to the thickness, compactness, and stability of the gases that surround them. Terrestrial planets have thin or no atmospheres, except Earth, which has a thick and stable atmosphere that supports life. Gaseous planets have very thick and compact atmospheres, which create unusual weather phenomena, such as storms, lightning, or polar circles. Planets can also have different atmospheric characteristics, such as color, temperature, pressure, or wind speed.

According to satellites , planets can be classified by the number, size, and shape of the smaller bodies that orbit them. Terrestrial planets have few or no satellites, except Earth, which has a natural satellite, the Moon. Gaseous planets have many satellites, ranging in size and shape from small rocks to dwarf planets such as Titan or Ganymede. Satellites can have different characteristics, such as surfaces, atmospheres, or life.

According to life, planets can be classified according to their ability to support the existence of living organisms. In the solar system, only Earth has life, due to favorable conditions such as temperature, atmosphere, water, and light. Other planets may not have life, due to unfavorable conditions such as temperature being too high or too low, atmosphere being too thick or too thin, water being too little or too much, and light being too bright or too dark. However, scientists are still studying the possibility of life on other planets, such as Mars, Mercury, or satellites of gaseous planets.

The planets in the Solar System have several characteristics in common, including:

• Orbit around the Sun: All planets revolve around the Sun in elliptical orbits.
• Gravity: The Sun’s gravitational pull keeps the planets in their orbits.
• Hard surface: Planets have hard surfaces, made of rock, metal, or ice.
• Atmosphere: Some planets have atmospheres, consisting of gases, water vapor, and dust.

In addition, the planets in the Solar System also have some different characteristics, such as:

• Size: Planets vary in size, from the smallest Mercury to the largest Jupiter.
• Mass: The planets range in mass from the smallest Mercury to the largest Jupiter.
• Temperature: The surface temperatures of the planets vary, from the hottest Mercury to the coldest Neptune.
• Composition: The composition of the planets varies, from Mercury and Venus being mostly rocky to Jupiter and Saturn being mostly gaseous.

Classification of planets

In the solar system, there are eight major recognized planets, namely Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. These planets can be divided into two main groups, the terrestrial planets and the gaseous planets.

Terrestrial planets are smaller planets with solid surfaces and little or no atmosphere. The four closest planets to the Sun are Mercury, Venus, Earth, and Mars. Terrestrial planets are made up primarily of the elements iron, magnesium, aluminum, silicon, oxygen, and carbon. Terrestrial planets have few or no satellites, except Earth, which has one natural satellite, the Moon. Of the terrestrial planets, only Earth is habitable, due to its favorable conditions such as temperature, atmosphere, water, and light.

Gas planets are larger, have less defined surfaces, and have dense atmospheres. The four planets furthest from the Sun are Jupiter, Saturn, Uranus, and Neptune. Gas planets are made up primarily of elements such as hydrogen, helium, nitrogen, and methane. Gas planets have many moons, ranging in size and shape from small rocks to dwarf planets such as Titan and Ganymede. Gas planets may be inhospitable to life, due to unfavorable conditions such as temperatures that are too high or too low, atmospheres that are too thick or too thin, water that is too little or too much, and light that is too bright or too dark.

This is a way of classifying the planets in the solar system into two main groups, the terrestrial planets and the gaseous planets. In addition, the planets in the solar system can also be classified based on other characteristics, such as:

• Size: Planets vary in size, from the smallest Mercury to the largest Jupiter.
• Mass: The planets range in mass from the smallest Mercury to the largest Jupiter.
• Temperature: The surface temperatures of the planets vary, from the hottest Mercury to the coldest Neptune.
• Composition: The composition of the planets varies, from Mercury and Venus being mostly rocky to Jupiter and Saturn being mostly gaseous.

The planets in our solar system are diverse and rich celestial bodies, with many features and mysteries yet to be discovered. Classifying the planets in our solar system is a way to help us better understand these celestial bodies and how they formed and evolved.

The planets in the Solar System can be classified in many different ways, based on their characteristics. One common classification is into two main groups:

• Terrestrial planets: Terrestrial planets are located in the inner part of the Solar System and include Mercury, Venus, Earth, and Mars. These planets have solid surfaces, made up mainly of rock and metal.
• Gas Giant Planets: The gas giant planets are located in the outer part of the Solar System and include Jupiter, Saturn, Uranus, and Neptune. These planets have surfaces that are mostly gas and liquid.

Another classification is based on their ability to clear their orbital neighborhood. According to the definition adopted by the International Astronomical Union (IAU) on August 24, 2006, a planet is a celestial body that is massive enough to have formed into a sphere, and has cleared its orbital neighborhood. According to this definition, Pluto, once considered the ninth planet in the Solar System, is now classified as a dwarf planet.

Some interesting facts about the planets in the Solar System

• Mercury: The Hottest and Fastest Planet
• Venus: The Most Earth-Like and Brightest Planet
• Earth: The Only Planet With Life and Liquid Water
• Mars: The Red Planet and the Possibility of Life
• Jupiter: The Largest Planet and Has the Most Satellites
• Saturn: The Planet With The Most Beautiful Rings and Strongest Winds
• Uranus: The Most Inclined and Coldest Planet
• Neptune: The Bluest and Farthest Planet