There are eight major classified planets in the solar system. In order of distance from the sun, they are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. Pluto is a ninth Dwarf Planet.
Each planet has its own unique features, from Mercury’s miniature size to Neptune’s giant storms.
The planets also vary widely in their potential for life. While some, like Venus, are incredibly hostile to life as we know it, others, like Earth, are teeming with life.
The solar system also contains a number of smaller bodies, including asteroids, comets, and meteoroids.
Some of them, like comets, which are made of volatile ices. Others, like meteoroids, are pieces of rock that have broken off of larger bodies like asteroids or planets.
However, these are not considered to be planets. The International Astronomical Union (IAU) is the organization responsible for classifying objects in the solar system.
The (IAU) currently defines a planet as a celestial body that orbits the sun, is massive enough to be spherical in shape, and has a gravitational field which has an orbit that is clear of any similar sized objects.
Many people ask the question whether or not Pluto is considered a planet.
In a related post, we have that question covered in detail where we cover the most common questions about Pluto.
For quick reference, the eight planets in the solar system plus Pluto (A Dwarf Planet) are as follows (in order of distance from the sun):
- Mercury
- Venus
- Earth
- Mars
- Jupiter
- Saturn
- Uranus
- Neptune
- Pluto
An easy way to remember the planet names is achieved by using a mnemonic sentence.
Here’s what it looks like: My Very Earnest Mother Just Served Us Nine Pancakes! ⏩⏬
- My = Mercury
- Very = Venus
- Earnest = Earth
- Mother = Mars
- Just = Jupiter
- Served = Saturn
- Us = Uranus
- Nine = Neptune
- Pancakes = Pluto – Reclassified in 2006 as a Dwarf Planet.
What are the Planets in the Solar System?
Lets take an interesting further look at the 9 planets in the solar system as they appear in order of distance from the Sun. ⏩⏬
1.) Mercury: The smallest and innermost planet
Mercury is the smallest planet and is closest to the sun. Mercury is only slightly larger than Earth’s moon. It has a very thin atmosphere and is covered in craters. It has no moons.
2.) Venus: The second planet from the sun in our solar system
Venus is the second planet from the sun. It is similar in size to Earth and has a thick atmosphere.
However, Venus is much hotter than Earth due to its proximity to the sun and its thick atmosphere. Venus has no moons.
As the second planet from the sun. It is sometimes called the Earth’s twin because it is similar in size.
However, Venus has a very different climate. It has very hot temperatures and sulphuric acidic rain. However, despite being very corrosive, this acidic rain never reaches the surface. Venus also has very active volcanoes.
3.) Earth: The third planet from the sun
Earth is the third planet from the sun. It is the only planet known to support life. The Earth has one moon.
It is the largest of the terrestrial planets (or the 4 innermost planets: Earth, Mars, Venus and Mercury) and has one moon. Earth has a thin atmosphere and is covered in oceans of water.
4.) Mars: The fourth planet from the sun
Mars is smaller than Earth and has a very thin atmosphere. It is covered in red dust and has mountains and canyons.
Mars is the fourth planet from the sun. It is red because of all the iron oxide on its surface. Mars has two moons, Phobos and Deimos.
5.) Jupiter: The fifth planet from the sun in our solar system
Jupiter is the largest planet in the solar system. It has a thick atmosphere and is mostly made of gas. It also has many moons.
Jupiter is the fifth planet from the sun. Jupiter is huge! It is twice as big as all of the other planets combined! Jupiter also has a faint ring system.
Jupiter is a gas giant with many moons. Jupiter’s largest moon, Io, has active volcanoes.
6.) Saturn: The sixth planet from the sun
Saturn is the sixth planet from the sun. Like Jupiter, it has a ring system that can be seen from Earth with a telescope. Saturn’s rings are made of ice and rock particles.
Saturn is similar to Jupiter but smaller. It has a thick atmosphere and is mostly made of gas. It also has many moons and rings made of ice.
Saturn is the sixth planet from the sun. It is a gas giant with many moons. Saturn’s largest moon, Titan, has an atmosphere similar to that of Earth’s early atmosphere.
7.) Uranus: The seventh planet from the sun in our solar system
Uranus is much smaller than Jupiter and Saturn. It has a thin atmosphere and is mostly made of gas. It also has many moons.
Uranus is seventh planet from the sun. Uranus was discovered in 1781 by William Herschel.
Uranus is the seventh planet from the sun. It is a gas giant with many moons. Uranus has two sets of rings around it made up of small rocks and dust particles.
It was originally thought to be a star because it appears blue-green in color. Uranus has 27 moons, more than any other planet in our solar system!
8.) Neptune: The eighth planet from the sun
Neptune is the eighth and final planet from the sun. It is a gas giant with many moons.
Neptune has an active weather system with large storms that can be seen from Earth with a telescope
Neptune is similar to Uranus but smaller. It has a thin atmosphere and is mostly made of gas.
Neptune was discovered in 1846 by Johann Galle. Its atmosphere contains methane gas, which makes it appear blue in color
9.) Pluto – A beloved dwarf planet
Pluto is a small, rocky world orbiting in the outer reaches of the solar system. It’s about half the size of Earth’s moon and has only a fraction of the Earth’s mass.
Pluto was discovered in 1930 by American astronomer Clyde Tombaugh and was originally considered to be the ninth major planet from the sun.
But after further study, scientists now believe that Pluto is more similar in size and composition to other objects orbiting in the Kuiper Belt, a region of space beyond Neptune.
In 2006, Pluto was officially re-classified as a “dwarf planet.”
It has a rocky surface with icy plains, and has 5 moons orbiting it.
FREQUENTLY ASKED QUESTIONS
Q: What are the dwarf planets in our solar system?
A: Dwarf planets are celestial bodies that orbit the Sun and are spherical in shape but do not clear their orbital path of other debris. The recognized dwarf planets in our solar system include Pluto, Eris, Haumea, Makemake, and Ceres. Unlike the eight major planets, these objects are part of a category that acknowledges their inability to clear their orbits due to their smaller size.
Q: What is the order of the planets from the Sun?
A: The order of the planets in our solar system, starting from the closest to the Sun, is: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. This sequence reflects the increasing distance each planet has from the Sun. If we include dwarf planets like Pluto, it would come after Neptune, though it is no longer classified as a major planet.
Q: Why do some planets have rings?
A: Planetary rings are primarily composed of dust, rock, and ice particles that orbit around a planet in a flat, disc-like structure. Gas giants like Jupiter, Saturn, Uranus, and Neptune have rings due to their strong gravitational pull, which captures debris from space. Saturn’s rings are the most prominent and visible, but all four of these gas giants possess ring systems to varying extents.
Q: How do planets form?
A: Planets form from the accretion of dust and gas in a protoplanetary disk surrounding a young star. Over time, particles within this disk collide and stick together, gradually building up to form larger bodies called planetesimals. Through continuous accumulation and collision, these planetesimals grow into planets. This process can take millions of years, with gravity playing a key role in drawing material together.
Q: What is the hottest planet in our solar system?
A: The hottest planet in our solar system is Venus. Despite not being the closest planet to the Sun (Mercury holds that title), Venus experiences extreme temperatures due to its thick atmosphere composed mostly of carbon dioxide. This atmosphere creates a greenhouse effect that traps heat, causing surface temperatures to soar above 900°F (475°C), making Venus even hotter than Mercury.
Q: What are the gas giants in our solar system?
A: The gas giants in our solar system are Jupiter, Saturn, Uranus, and Neptune. These planets are called gas giants because they are composed mainly of hydrogen and helium, and lack a solid surface like the terrestrial planets. Jupiter and Saturn are primarily made of gas, while Uranus and Neptune also contain heavier elements and ices, leading to their classification as “ice giants.”
Q: How do you remember the planets in order?
A: A popular mnemonic to remember the order of the planets from the Sun is: “My Very Educated Mother Just Served Us Noodles.” Each word’s first letter corresponds to the first letter of each planet: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. This mnemonic makes it easier to recall the sequence quickly.
Q: What are the terrestrial planets?
A: The terrestrial planets in our solar system are Mercury, Venus, Earth, and Mars. These planets are characterized by their solid, rocky surfaces and are the closest planets to the Sun. Unlike the gas giants, terrestrial planets have a well-defined surface with mountains, valleys, and in some cases, active volcanoes. Earth is the largest of these planets.
Q: Who discovered Pluto?
A: Pluto was discovered by Clyde Tombaugh in 1930. Tombaugh, an American astronomer, found Pluto while working at the Lowell Observatory in Flagstaff, Arizona. His discovery was a result of painstaking work observing and comparing photographs of the night sky, looking for a moving object that would indicate a planet beyond Neptune.
Q: Why is Earth the only planet with life?
A: Earth is the only planet known to support life due to its unique combination of factors. It has a breathable atmosphere rich in oxygen, a protective magnetic field, liquid water, and a stable climate. These conditions create an environment where diverse forms of life can thrive. Other planets either lack these elements or have extreme conditions that are hostile to life as we know it.
Q: How are planets different from stars?
A: Planets and stars differ in several key ways. Stars, like our Sun, are massive celestial bodies that generate light and heat through nuclear fusion in their cores. Planets, on the other hand, do not produce their own light; they reflect the light of a star. Planets also orbit stars, whereas stars are the central objects in their systems, often with planets, moons, and other objects orbiting them.
Q: What is the smallest planet in our solar system?
A: The smallest planet in our solar system is Mercury. It has a diameter of about 3,031 miles (4,880 kilometers), making it slightly larger than Earth’s Moon. Despite its small size, Mercury has a significant gravitational pull and experiences extreme temperatures due to its proximity to the Sun.
Q: Why are there so many planets?
A: The number of planets in a solar system depends on the conditions during the formation of that system. In our solar system, a mix of dust, gas, and other materials in the protoplanetary disk coalesced into planets. The diversity in planet types, from rocky to gaseous, is a result of varying distances from the Sun and the different materials available in those regions during formation.
Q: What defines a planet?
A: A planet is defined by three criteria: it must orbit the Sun, have sufficient mass to assume a nearly round shape, and have cleared its orbital path of other debris. This definition was established by the International Astronomical Union (IAU) in 2006, which led to Pluto being reclassified as a dwarf planet because it does not meet the third criterion.
Q: What is the coldest planet in our solar system?
A: The coldest planet in our solar system is Uranus. Despite being further from the Sun, Neptune has a warmer atmosphere than Uranus. Uranus experiences temperatures as low as -371°F (-224°C). This extreme cold is due to its lack of internal heat and its distance from the Sun.
Q: Why are some planets considered dwarf planets?
A: Dwarf planets are celestial bodies that share many characteristics with planets but do not meet all the criteria required to be classified as a full planet. The primary reason for this classification is that dwarf planets, such as Pluto and Eris, have not cleared their orbits of other debris. This means they share their orbital space with other objects of similar size.
Q: Which is the largest planet in our solar system?
A: The largest planet in our solar system is Jupiter. It has a diameter of about 86,881 miles (139,822 kilometers), making it over 11 times wider than Earth. Jupiter’s massive size also makes it incredibly dense and gravitationally dominant, capable of influencing the orbits of other objects in the solar system.
Q: What is a solar system?
A: A solar system is a collection of celestial bodies, including planets, moons, asteroids, comets, and other objects that orbit a star. In our case, the Sun is the central star, and all the planets and other bodies orbit around it due to its gravitational pull. Solar systems are common in the universe, with billions of stars hosting their own systems.
Q: Are there lots of solar systems in the galaxy?
A: Yes, there are billions of solar systems in our galaxy, the Milky Way. Each star in the galaxy is likely to have its own solar system, similar to how our Sun has its own set of planets and other celestial objects. The diversity and number of these systems suggest that planets are common throughout the galaxy.
Q: What are exoplanets?
A: Exoplanets are planets that orbit stars outside of our solar system. These planets are located in distant solar systems, and thousands have been discovered by astronomers using telescopes and other instruments. Some exoplanets are similar to Earth and are of great interest in the search for potential extraterrestrial life.
Q: What is the Kuiper Belt?
A: The Kuiper Belt is a region of the solar system beyond the orbit of Neptune, populated with many small, icy bodies and dwarf planets like Pluto. This belt is similar to the asteroid belt but much larger and farther from the Sun. Objects in the Kuiper Belt are remnants from the solar system’s formation, offering clues about its early history.
Q: Which planet has the most moons?
A: Jupiter has the most moons in our solar system, with 95 confirmed moons as of 2023. These moons vary in size and composition, with Ganymede being the largest moon in the solar system. Saturn also has a significant number of moons, many of which are still being studied and discovered.
Q: Do all planets have moons?
A: Not all planets in our solar system have moons. While most of the planets have at least one moon, Mercury and Venus are the exceptions; neither of them has any natural satellites. The other planets have varying numbers of moons, with Jupiter and Saturn having the most.
Q: How long is a day on Jupiter?
A: A day on Jupiter is incredibly short, lasting only about 10 hours. This is because Jupiter rotates very quickly on its axis, completing one rotation in less than half the time it takes Earth. Despite its rapid rotation, Jupiter’s massive size makes its days relatively short compared to Earth.
Q: What is the Great Red Spot on Jupiter?
A: The Great Red Spot is a massive storm on Jupiter, larger than the entire Earth. This storm has been raging for at least 350 years, and possibly much longer. It is characterized by its reddish color and oval shape and is located in Jupiter’s southern hemisphere. The storm is a high-pressure region with wind speeds that can exceed 400 miles per hour.
Q: Why do some planets have atmospheres?
A: Atmospheres form around planets due to their gravitational pull, which holds onto gases that were present during the planet’s formation or were captured from the surrounding space. The composition of these atmospheres depends on the planet’s size, temperature, and location in the solar system. Planets like Earth and Venus have thick atmospheres, while smaller planets like Mercury have little to no atmosphere due to weaker gravity.
Summary
There are nine planets in the solar system. In order of distance from the sun, they are: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto.
Mercury is the closest planet to the sun, and it is also the smallest planet in the solar system.
Venus is the second planet from the sun, and it is the hottest planet in the solar system.
Earth is the third planet from the sun, and it is the only planet on which humans live.
Mars is the fourth planet from the sun, and it is known as the “red planet” because of its red soil. Jupiter is the fifth planet from the sun, and it is the largest planet in the solar system.
Saturn is the sixth planet from the sun, and it is known for its beautiful rings.
Uranus is the seventh planet from the sun in our solar system and it is often referred to as the “ice giant” because of its cold temperatures.
Neptune is the eighth planet from the sun, and it is known for its strong winds.
