The planets in order from the Sun

The planets in order of distance, size, mass and more

Last Updated: January 23, 2023

Is the order of the planets in our solar system important? In a sense yes, because the solar system as we know it depends strongly on the gravitational influences that every planet exerts on one another.

The entire stability of our solar system is based on the current order and location of the planets. Jupiter (5th planet) is the planet that exerts the strongest gravitational influence on the solar system after the Sun. 

If this giant planet was placed at the outskirts of the system, say after Neptune (8th planet), the whole order of the planets would be affected as well as their distance from the Sun. Life might not have started on Earth and you would not be reading this article right now.

In this article, we will examine the order of the planets from the Sun and how to remember it. We will also rank them according to their size, mass, orbital period, and rotation period. Enjoy!

Table of Contents

What is the order of the planets from the sun?

Mercury is the first planet

Mercury is the first planet in our solar system. It is the closest planet to the Sun, located at an average distance of 36 million miles (58 million kilometres) from our star. Because this small planet is so close to the Sun’s harmful solar winds, it has the thinnest atmosphere of all planets.

picture of planet Mercury

Did you know that it’s the smallest planet in our solar system? It’s only about a third the size of Earth! But even though it’s small, it’s still pretty dense. That’s because it’s made mostly of heavy elements like iron and silicon.

Mercury also has some unique features, like its extremely long day and year. One day on Mercury (the time it takes for it to rotate once) is actually about 176 Earth days long! And one year on Mercury (the time it takes for it to orbit the Sun) is only about 88 Earth days. So if you were to live on Mercury, your birthday would come around more than three times a year!

Another interesting thing about Mercury is that it has a heavily cratered surface, much like the Moon. These craters were formed by comet and asteroid impacts that happened early in the solar system’s history. Some of the largest craters on Mercury are named after famous artists, such as the Salvador Dali crater.

Mercury also has a very thin atmosphere and no known magnetic field. It’s also the closest planet to the sun, and because of that, it experiences extreme temperature changes. The side facing the sun can reach up to 800 degrees Fahrenheit while the side facing away from the sun can drop to -290 degrees Fahrenheit.

Mercury is also one of the least explored planets in our solar system, with only two missions ever having been sent to study it. But NASA plans to send another mission in the near future to study Mercury’s geology and magnetic field in more detail.

Mercury Information & Facts

  • Discovery: The discovery of Venus is not attributed to any specific person. Mercury was known to ancient civilizations.
  • Name origin: Named after the Roman messenger god.
  • Type: Terrestrial/Rocky
  • Category: Inner/inferior planet
  • Diameter: 4,880 km (0.38 times that of Earth)
  • Mass: 3.285 x 10^23 kg (0.055 times that of Earth)
  • Average distance from the Sun: 57.734 million km (0.39 AU)
  • Orbital period (year): 87.97 Earth days
  • Orbital velocity: 47.87 km/s (29.78 miles/s)
  • Rotation period (day): 58.65 Earth days (synchronous rotation)
  • Surface gravity: 3.7 m/s² (0.38 g)
  • Surface temperature: -173 to 427 °C (-279 to 801 °F)
  • Atmosphere: Extremely thin, composed mainly of hydrogen, helium, oxygen, sodium, calcium, potassium and water vapor.
  • Surface features: Impact craters and basins, scarps, and ridges.
  • Number of natural satellites (moons): None
  • Ring System: None
  • Magnetic field: Weak, only 1% the strength of Earth’s
  • Surface pressure: Very low, about 1/100,000th of Earth’s at sea level.
  • Reflectivity (albedo): Low (about 0.12)
  • Exploratory missions: 3
  • How long does it take for sunlight to reach it: 3.2 minutes.
  • Stargazing observability: Easy
  • Planetary protection: Category 2
  • Habitability: Not currently habitable for known forms of life due to its proximity to the sun, lack of atmosphere, and extreme temperatures.
  • Potential for human colonization: Very low
  • Evidence of current life: None detected to this day.

Venus is the second planet

Venus is the second planet in our solar system. It is located at an average distance of 67 million miles (108 million kilometers) from our star. 

Venus is unfortunately a little too close to the Sun for life to develop there. 

picture of planet Venus

Venus is often called Earth’s twin because it’s about the same size and mass as our planet. But that’s about where the similarities end! Venus has a thick, toxic atmosphere that’s mostly made up of carbon dioxide, with clouds of sulfuric acid. The atmosphere is so thick that it traps heat, making Venus the hottest planet in our solar system. The surface temperature can reach up to 864 degrees Fahrenheit, hot enough to melt lead!

One of the most interesting things about Venus is that it has extremely active volcanoes. Scientists believe that Venus has over a thousand active volcanoes, and some of them are much larger than any volcano on Earth. The largest volcano on Venus is called the Rhea Montes and it’s as tall as Mount Everest.

Venus also rotates very slowly on its axis, a day on Venus is longer than a year! It takes about 243 Earth days for Venus to rotate once on its axis, but only 225 Earth days to orbit the sun. A fun fact about this planet is that it rotates backwards compared to earth’s rotation… This means that the sun rises in the west and sets in the east on Venus.

Another interesting fact is that Venus is the brightest object in the sky after the Sun and the Moon, and it can often be seen with the naked eye. It’s also one of the most studied planets in our solar system, with several missions sent to study its atmosphere and surface.

Scientists believe that Venus may have had liquid water on its surface in the past, and it’s possible that it might still have microbial life in its clouds.

Venus Information & Facts

  • Discovery: The discovery of Venus is not attributed to any specific person because it has been known since ancient times and has been observed by many cultures throughout history.
  • Name origin: Roman goddess of love and beauty.
  • Type: Terrestrial/Rocky
  • Category: Inferior/Inner plannet
  • Diameter: 12,104 km (0.95 times that of Earth)
  • Mass: 4.87 × 10^24 kg (0.81 times that of Earth)
  • Average distance from the Sun: 108.8 million km (0.72 AU)
  • Orbital period (year): 224.7 Earth days
  • Orbital velocity: 35.02 km/s (21.75 miles/s)
  • Rotation period (day): 243 Earth days (retrograde rotation)
  • Surface gravity: 8.87 m/s² (0.904 g)
  • Surface temperature: average of 464 °C (867 °F)
  • Atmosphere: 96.5% carbon dioxide, 3.5% nitrogen, trace amounts of sulfur dioxide, argon, and water vapor
  • Surface features: Volcanoes, mountains, and impact craters
  • Number of natural satellites (moons): None
  • Ring System: None
  • Magnetic field: None
  • Surface pressure: 90 bar. About 90 times that of Earth’s atmosphere at sea level.
  • Reflectivity (albedo): High (about 0.75)
  • Exploratory missions: 46
  • How long does it take for sunlight to reach it: 6 minutes
  • Stargazing observability: Very easy
  • Planetary protection: Category 2
  • Habitability: Not currently habitable for known forms of life due to extremely high surface temperatures and a toxic atmosphere.
  • Potential for human colonization: Low.
  • Evidence of current life: None detected to this day.

Earth is the third planet

Earth is the third planet in our solar system. It is located at an average distance of 92.96 million miles (149.60 million km) from our star. Our beautiful planet is ideally placed inside the goldilock zone, making it the only planet of our solar system where intelligent life could thrive.

planet-earth

One of the most interesting things about Earth is its atmosphere. The atmosphere is made up of 78% nitrogen, 21% oxygen, and small amounts of other gases like argon and carbon dioxide. This mixture of gases is perfect for life, as it protects us from harmful radiation from the sun and helps regulate the temperature.

Earth also has a magnetic field that helps protect us from harmful solar radiation, and it’s responsible for the beautiful auroras that can be seen in the northern regions.

Earth’s surface is also very diverse and unique, it’s covered by 70% water and the remaining 30% is land, and it’s home to a wide variety of plants and animals. From the highest mountain to the deepest ocean trench, Earth has an incredible variety of environments that support an amazing diversity of life. But you should already know all of that since you live on this amazing planet!

Earth Information & Facts

  • Discovery: since the birth of mankind.
  • Name origin: English word for the planet we live on.
  • Type: Terrestrial/Rocky
  • Category: Inner/Inferior planet
  • Diameter: 12,742 km
  • Mass: 5.97 x 10^24 kg
  • Average distance from the Sun: 147.19 million km (1 AU)
  • Orbital period (year): 365.25 Earth days
  • Orbital velocity: 29.78 km/s (18.5 miles/s)
  • Rotation period (day): 24 hours
  • Surface gravity: 9.8 m/s² (1 g)
  • Surface temperature: -89 to 35 °C (-128 to 95 °F)
  • Atmosphere: 78% Nitrogen, 21% Oxygen, and trace amounts of other gases
  • Surface features: Oceans, mountains, valleys, deserts, and polar ice caps.
  • Number of natural satellites (moons): 1
  • Ring System: None
  • Magnetic field: Yes
  • Surface pressure: 1013 hPa (at sea level)
  • Reflectivity (albedo): Moderate (about 0.31)
  • Exploratory missions: Many
  • How long does it take for sunlight to reach it: 8 minutes and 20 seconds.
  • Stargazing observability: Not applicable since we live on it.
  • Planetary protection: Category 1
  • Habitability: Currently habitable for known forms of life due to its atmosphere, liquid water, and moderate temperatures.
  • Potential for human colonization: Very high
  • Evidence of current life: Abundant

Mars is the fourth planet

Mars is the fourth planet in our solar system. It is located at an average distance of 142 million miles (228 million kilometers) from our star. Sadly, this means the red planet is too far away from the goldilocks zone which means that life was not able to flourish like it did on Earth.

picture of planet mars

Mars is a rocky planet, and it has a cold, thin atmosphere that’s mostly made up of carbon dioxide.

One of the coolest fact about Mars is that it has the largest volcano in the solar system, Olympus Mons. It’s three times taller than Mount Everest! Mars also has the largest canyon in the solar system, Valles Marineris, which is over 4,000 km (2,500 miles) long and 7 km (4 miles) deep.

Another interesting fact about Mars is that it has polar ice caps made of water and carbon dioxide. Scientists believe that liquid water might exist just below the surface in certain regions of Mars, which raises the possibility that the planet might have supported life in the past, or even still support microbial life.

Another interesting characteristic of the red planet is that it is home to the largest dust storms in the solar system, these storms can cover the entire planet and last for months! You might have seen an interpretation of what they might look like in the 2015 space movie “The Martian”.

Mars has been explored by several missions, including NASA’s robotic rovers and landers, which have discovered evidence of past water on Mars and have provided valuable information about its geology, atmosphere, and potential for life.

In the future, NASA and other space agencies plan to send more missions to Mars to continue the search for signs of life, and even eventually send humans to the planet

Mars Information & Facts

  • Discovery: Mars has been known since ancient times and has been observed by many cultures throughout history.
  • Name origin: Named after the Roman god of war
  • Type: Terrestrial/Rocky
  • Category: Inner/Inferior planet
  • Diameter: 6,779 km (0.53 times that of Earth)
  • Mass: 6.39 x 10^23 kg (0.107 times that of Earth)
  • Average distance from the Sun: 238.69 million km (1.52 AU)
  • Orbital period (year): 687 Earth days
  • Orbital velocity: 24.077 km/s (14.995 miles/s)
  • Rotation period (day): 24.6 Earth hours (1.03 Earth days)
  • Surface gravity: 3.721 m/s² (0.38 g)
  • Surface temperature: -87 to -5 °C (-125 to 23 °F)
  • Atmosphere: 96% carbon dioxide, 1.9% argon, 2.6% molecular nitrogen and trace amounts of oxygen, and carbon monoxide.
  • Surface features: Volcanoes, mountains, valleys, and impact craters
  • Number of natural satellites (moons): 2 (Phobos and Deimos)
  • Ring System: None
  • Magnetic field: None
  • Surface pressure: 6.518 millibars (0.6% of Earth’s at sea level)
  • Reflectivity (albedo): Low (about 0.16)
  • Exploratory missions: More than 50.
  • How long does it take for sunlight to reach it: 13.4 minutes
  • Stargazing observability: Very easy
  • Planetary protection: Category 3
  • Habitability: Not currently habitable for known forms of life, but has potential for future habitability through terraforming or the use of underground shelter.
  • Potential for human colonization: Moderate to high
  • Evidence of current life: None detected to this day.

Jupiter is the fifth planet

Jupiter is the fifth planet in our solar system. It is located at an average distance of 484 million miles (778 million kilometers) from our star. Jupiter is nicknamed the godfather of the solar system because its very strong gravitational influence attracts smaller objects such as asteroids towards the gas giant. Jupiter indirectly provides some protection to the 7 other planets, including the Earth, against asteroids.

Jupiter soundscape

Jupiter is the largest planet in our Solar System, it’s a gas giant and it’s known for its giant red spot, which is a giant storm that’s been raging for hundreds of years. It’s also known for its many moons, including the four largest moons in the solar system, called the Galilean moons, named after Galileo Galilei who discovered them in 1610: Io, Europa, Ganymede, and Callisto.

Many amateur stargazers enjoy observing Jupiter through backyard telescopes due to its unique and striking appearance, which is made up of various layers and swirling patterns.

Jupiter is not only a favorite among amateur stargazers but also among the scientific community. It has been the subject of many missions and studies, with many spacecraft sent to observe and analyze the gas giant. Scientists currently believe that one of Jupiter’s moons, Europa, may potentially host life within its underground ocean.

Despite the fact that Jupiter’s surface is not suitable for human colonization, it still holds a great deal of interest and potential for scientific discoveries and exploration.

Jupiter Information & Facts

  • Discovery: Jupiter has been known since ancient times and has been observed by many cultures throughout history.
  • Name origin: Named after the king of the Roman gods.
  • Type: Gas giant.
  • Category: Outer/Superior planet.
  • Diameter: 139,822 km (11.2 times that of Earth).
  • Mass: 1.898 x 10^27 kg (317.83 times that of Earth).
  • Average distance from the Sun: 740 million km (5.20 AU).
  • Orbital period (year): 11.86 Earth years.
  • Orbital velocity: 13.06 km/s (8.1 miles/s).
  • Rotation period (day): 9 hours and 56 minutes.
  • Surface gravity: 24.79 m/s² (2.53 g)
  • Surface temperature: -145 °C (-234 °F)
  • Atmosphere: 89% hydrogen, 11% helium, trace amounts of methane, ammonia, water vapor, and other elements.
  • Surface features: Cloud bands, storms and the Great Red Spot (a giant storm).
  • Number of natural satellites (moons): 84.
  • Ring System: Yes (4 main rings).
  • Magnetic field: Yes (14 times stronger than Earth’s).
  • Surface pressure: Unknown (too deep to measure).
  • Reflectivity (albedo): Moderate (about 0.52).
  • Exploratory missions: 9.
  • How long does it take for sunlight to reach it: 43 minutes.
  • Stargazing observability: Very easy.
  • Planetary protection: Category II.
  • Habitability: Not currently habitable for known forms of life due to the lack of solid surface, high pressure, and extremely low temperatures.
  • Potential for human colonization: None,
  • Evidence of current life: None detected to this day.

Saturn is the sixth planet

Saturn is the sixth planet in our solar system. It is located at an average distance of 886 million miles (1.4 billion kilometers) from our star. It is believed that Saturn’s gravitational influence on Jupiter once slowed down the gas giant enough to prevent it from moving towards the interior of the solar system, where the rocky planets are.

a picture of planet Saturn

Saturn is mostly known for its beautiful rings, which are made up of ice and rock particles. Saturn is primarily composed of hydrogen and helium, and has a low density, meaning that it would float if placed in water.

Saturn currently holds the title of the planet with the most moons, one of them being Titan, which is the second-largest moon in the solar system. This wonderful Saturnian moon has a thick atmosphere and lakes of liquid methane on its surface. 

The planet’s atmosphere is also known for its strong winds and storms, including the Great White Oval, a giant storm that occurs periodically every few years.

The wind speeds on Saturn can reach as high as 1,800 km/h, which is equivalent to around 1,118 miles per hour. To compare, the speed of sound is approximately 767 miles per hour (1234 km/h) at sea level on Earth. Mind blown!

Thanks to the Cassini probe, we have been able to collect stunning images of this majestic planet over the last decade. 

The next scheduled mission to Saturn will explore Titan! The NASA mission Dragonfly is scheduled to launch in 2027, it is a drone-like craft called a quadcopter that will attempt to seek signs of life within the moon’s atmosphere and surface.

Saturn Information & Facts

  • Discovery: Saturn has been known since ancient times and has been observed by many cultures throughout history.
  • Name origin: Named after the Roman god of agriculture, and wealth.
  • Type: Gas giant.
  • Category: Outer/Superior planet.
  • Diameter: 116,460 km (9.14 times that of Earth)
  • Mass: 5.68 x 10^26 kg (95.16 times that of Earth)
  • Average distance from the Sun: 1.4 billion km (9.58 AU)
  • Orbital period (year): 29.46 Earth years
  • Orbital velocity: 9.69 km/s (6.0 miles/s)
  • Rotation period (day): 10 hours, 39 minutes, and 24 seconds
  • Surface gravity: 10.44 m/s² (1.07 g)
  • Surface temperature: -139 °C (-218 °F)
  • Atmosphere: 75% hydrogen, 24% helium, 1% methane, ammonia, water vapor, and other elements.
  • Surface features: Cloud bands, storms, hexagonal jet stream, and hexagonal cloud pattern around the north pole of the planet.
  • Number of natural satellites (moons): 83.
  • Ring System: Yes (7 main rings).
  • Magnetic field: Yes (578 times stronger than Earth’s).
  • Surface pressure: Unknown (too deep to measure).
  • Reflectivity (albedo): Moderate (about 0.34).
  • Exploratory missions: 5.
  • How long does it take for sunlight to reach it: 80 minutes.
  • Stargazing observability: Very easy.
  • Planetary protection: Category II
  • Habitability: Not currently habitable for known forms of life due to the lack of solid surface, high pressure, and extremely low temperatures.
  • Potential for human colonization: None
  • Evidence of current life: None detected to this day.

Uranus is the seventh planet

Uranus is the seventh planet in our solar system. It is located at an average distance of 1.8 billion miles (2.9 billion kilometers) from our star. The distant gas giant has a ring system just like Saturn. It is so far away that it’s a real challenge for any stargazers to observe Uranus through a telescope.

uranus

Uranus is a pretty unique planet in our solar system. For one thing, it’s the third largest planet, but it’s also the coldest. Its atmosphere is made mostly of methane, which gives it a blue-green color when sunlight reflects off of it.

Another interesting thing about Uranus is that it’s tilted on its side. The axial tilt is about 98 degrees. This means that its poles are nearly in the plane of its orbit, so its seasons are extreme. Scientists think that a massive collision with another object in its early history might have caused this. 

Uranus has 27 known moons, the most notable of which is Miranda, which has some of the most diverse terrain of any object in the Solar System. It also has 13 known rings and two sets of faint rings were discovered in recent years. 

Even though it’s not the most well-known planet, Uranus still has a lot of interesting things to offer for scientists.

Uranus Information & Facts

  • Discovery: Uranus was discovered by William Herschel in 1781.
  • Name origin: Named after the ancient Greek deity of the sky, Uranus.
  • Type: Gas giant.
  • Category: Outer/Superior planet.
  • Diameter: 50,724 km (4.0 times that of Earth).
  • Mass: 8.681 x 10^25 kg (14.536 times that of Earth).
  • Average distance from the Sun: 2.9 billion km (19.18 AU).
  • Orbital period (year): 84 Earth years.
  • Orbital velocity: 6.81 km/s (4.25 miles/s).
  • Rotation period (day): 17 hours and 14 minutes (Retrograde rotation).
  • Surface gravity: 8.87 m/s².
  • Surface temperature: -197 °C (-322 °F).
  • Atmosphere: 83% hydrogen, 15% helium, 2% methane, and trace amounts of other gases.
  • Surface features: Cloud bands, and storms.
  • Number of natural satellites (moons): 27.
  • Ring System: Yes (13 known rings).
  • Magnetic field: Yes (5% the strength of Earth’s).
  • Surface pressure: Unknown (too deep to measure).
  • Reflectivity (albedo): Moderate (about 0.58)
  • Exploratory missions: 1 (Voyager 2 in 1986)
  • How long does it take for sunlight to reach it: 2 hours and 40 minutes
  • Stargazing observability: Hard.
  • Planetary protection: Category II.
  • Habitability: Not currently habitable for known forms of life due to the lack of solid surface, high pressure, and extremely low temperatures.
  • Potential for human colonization: None.
  • Evidence of current life: None detected to this day.

Neptune is the eighth planet

Neptune is the eight planet in our solar system. It is located at an average distance of 2.8 billion miles (4.5 billion kilometers) from our star. The blue gas giant is the farthest and coldest planet in the solar system.

a picture of planet Neptune

It’s a really cold planet, with average temperatures around -200 degrees Celsius. It’s also incredibly windy, with winds reaching up to 2,100 kilometers per hour (the fastest winds in the solar system).

One of the most interesting things about Neptune is that it has a giant storm called the Great Dark Spot, which is similar to Jupiter’s Great Red Spot. 

It also has 14 known moons, the largest of which is Triton, which is a really unique moon because it orbits in the opposite direction of Neptune’s rotation. Triton is also the only large moon in the solar system with a retrograde orbit. 

Finally, a cool fact about Neptune is that it was the first planet to be discovered through mathematical predictions rather than through observation. It was discovered by Urbain Le Verrier, John Couch Adams and Johann Galle in 1846.

Neptune Information & Facts

  • Discovery: Neptune was first observed by Galileo Galilei in 1613, but was not recognized as a planet until 1846, when it was independently discovered by Johann Galle and Urbain Le Verrier.
  • Name origin: Named after the Roman god of the sea.
  • Type: Ice giant.
  • Category: Outer/Superior planet.
  • Diameter: 49,244 km (3.88 times that of Earth).
  • Mass: 1.024 x 10^26 kg (17.15 times that of Earth).
  • Average distance from the Sun: 4.5 billion km (30.07 AU).
  • Orbital period (year): 164.8 Earth years.
  • Orbital velocity: 5.43 km/s (3.36 miles/s).
  • Rotation period (day): 16 hours and 6.7 minutes (retrograde rotation).
  • Surface gravity: 11.15 m/s² (1.14 g).
  • Surface temperature: -201 °C (-330 °F).
  • Atmosphere: 80% hydrogen, 19% helium, 1.5% methane and trace amounts of other elements.
  • Surface features: Blue coloration caused by methane in the atmosphere, white clouds, and dark spots (similar to Jupiter’s Great Red Spot).
  • Number of natural satellites (moons): 14.
  • Ring System: Yes (5 known rings).
  • Magnetic field: Yes (27 times stronger than Earth’s).
  • Surface pressure: Unknown (too deep to measure).
  • Reflectivity (albedo): Moderate (about 0.41)
  • Exploratory missions: 1 (Voyager 2).
  • How long does it take for sunlight to reach it: 4 hours.
  • Stargazing observability: Very difficult.
  • Planetary protection: Category II.
  • Habitability: Not currently habitable for known forms of life due to the lack of a solid surface, extremely cold temperatures, and high pressure.
  • Potential for human colonization: None.
  • Evidence of current life: None detected to this day.

Recap: The planets in order of distance from the Sun

  1. Mercury – 36 million miles (58 million kilometres)
  2. Venus – 67 million miles (108 million kilometers)
  3. Earth – 92.96 million miles (149.60 million km)
  4. Mars – 142 million miles (228 million kilometers)
  5. Jupiter – 484 million miles (778 million kilometers)
  6. Saturn – 886 million miles (1.4 billion kilometers)
  7. Uranus – 1.8 billion miles (2.9 billion kilometers)
  8. Neptune – 2.8 billion miles (4.5 billion kilometers)
The planets in order from the Sun

How to memorize the order of the planets?

The easiest way to remember the order of the 8 planets is to use a mnemonic device. It’s simply a memorable sentence where the first letter of each word is the same first letter in the planet’s name. 

The most popular mnemonic device is: My Very Educated Mother Just Served Us Noodles.

The first letter of each word is M V E M J S U N which recalls the planet’s name: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune.

The planets in order of size (from largest to smallest)

The largest planets, rightly called the gas giants, are located on the outskirt of the solar system while the smallest, the rocky planets, are located in the inner region.

  1. Jupiter is first, with a diameter of 88,846 miles (142,800 km)
  2. Saturn is second, with a diameter of 74,900 miles (120,660 km)
  3. Uranus is third, with a diameter of 31,763 miles (51,118 km)
  4. Neptune is fourth, with a diameter of 30,779 miles (49,528 km)
  5. Earth is fifth, with a diameter of 7,926 miles (12,756 km)
  6. Venus is sixth, with a diameter of 7,521 miles (12,104 km)
  7. Mars is seventh, with a diameter of 4,222 miles (6787 km)
  8. Mercury is eighth, with a diameter of 3,031 miles (4879.4 km)

Memorization tip

If you want to remember the planets in order of size, from largest to smallest, you can use the following acrostic: Janet Saw Unicorns Negotiate Eagerly Versus Magical Mermaids.

The planets in order by size

The planets in order of mass (from heaviest to lightest)

The mass of a planet will dictate the amount of gravity it will produce. Gas giants are the heaviest planets and therefore have the most gravitational influence on the rest of the solar system. The mass of our planet is the reason why you are not floating away! Fun fact: your weight would be completely different on every planet in the solar system! 

    1. Jupiter: 1.8986 x 1027 kilograms
    2. Saturn: 5.6846 x 1026 kilograms
    3. Neptune: 10.243 x 1025 kilograms
    4. Uranus:  8.6810 x 1025 kilograms
    5. Earth: 5.9736 x 1024 kilograms
    6. Venus: 4.8685 x 1024 kilograms
    7. Mars: 6.4185 x 1023 kilograms
    8. Mercury: 3.3022 x 1023 kilograms

Memorization tip

If you want to remember the planets in order of mass, from heaviest to lightest, you can use the following acrostic: John Said NUnique  Eco Vegetables Made Margin.

In what order did the planets form in our Solar System?

The order of planet formation in the Solar System is still a topic of ongoing research and debate among scientists. However, the current leading theory is that the Solar System was formed through a process known as the “nebular hypothesis.” According to this theory, the Solar System formed from the collapse of a cloud of dust and gas called the solar nebula.

As the cloud collapsed, it began to spin faster and flatten into a disk shape. In the center of the disk, the Sun formed. The densest regions of the disk began to clump together to form the inner planets: Mercury, Venus, Earth, and Mars.

Farther out, in the colder regions of the disk, ices and gases such as water, methane and ammonia began to condense. These materials eventually formed into the outer planets: Jupiter, Saturn, Uranus, and Neptune. 

The current models also show that a significant number of small bodies such as asteroids and comets also formed from the same cloud.

It is important to note that this is a simplified version of the theory and many details of the process are still being studied and refined.

What caused the planets to be in that exact order?

The solar system began as a giant cloud of gas and dust where, at one point, gravity gathered enough matter to create the Sun, while the planets formed from the remnants of dust and gas left over after the Sun formed.

There are many theories as to why the planets are in this particular order, but none are 100% confirmed. It is thought that the solar winds may have pushed most of the gases further into the solar system where the gas giant formed, leaving behind mostly rock and dust that led to the formation of the rocky planet. This would explain why the inner solar system is populated only by rocky planets while the outer solar system is populated only by gas giants.

It’s important to note that the exact order and position of the planets might have changed during the early days of the solar system, due to gravitational interactions between the newly formed planets, which caused some of the planets to migrate to their current position.

To date, we do not know exactly why the planets are in this precise order, but we can imagine that it is mostly due to a long list of random factors that happened during the formation of the solar system, gravitational influences, impacts with other celestial bodies, etc.

The planets in order of orbital period around the Sun (from shortest to longest)

The orbital period is the time it takes for a given celestial object to complete a full orbit around another celestial object. In our case, we are looking at the orbital period of the planets around the Sun. No surprise here, the further a planet is from the Sun, the longer its orbital period will be.

  1. Mercury: 87.97 days (about 3 months)
  2. Venus: 224.70 days (about 7 months)
  3. Earth: 365.26 days (12 months)
  4. Mars: 686.98 days (about 2 years)
  5. Jupiter: 4,332.82 days (about 12 years)
  6. Saturn: 10,755.70 days (about 29.5 years)
  7. Uranus: 30,687.15 days (about 84 years)
  8. Neptune: 60,190.03 days (about 165 years)
The planets in order by orbital period around the Sun

The planets in order of rotation period around their axis (from shortest to longest)

The rotation period of a celestial object is the time it takes said object to complete a full revolution around its axis. For the 8 planets of our solar system, this indicates the length of their days. 

  1. Earth: 24 hours 
  2. Mars: 25 hours 
  3. Jupiter: 10 hours
  4. Saturn: 11 hours 
  5. Uranus: 17 hours 
  6. Neptune: 16 hours
  7. Mercury: 1,408 hours (58.6 days)
  8. Venus: 5,832 hours (243 days)
Tom Urbain

 I’ve been fascinated by space and astronomy from a very young age. When I’m not watching space-themed documentaries, movies or TV series, I spend most of my free time in my backyard admiring the planets and galaxies with my telescope.

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