What is a Gas Giant?

A Gas Giant is a large planet that is not primarily composed of rock or solid matter. These planets, often known as Jovian planets or giant planets, make up 1/2 of our solar system. In other words, Four of our eight planets are known as Gas Giants. Jupiter, Saturn, Uranus, and Neptune are all gas giants. Each is fairly massive with no solid surface, only a dense, hot atmosphere. They also have a large number of moons, and are surrounded by ring systems.

The name was created in 1952 by the science fiction writer James Blish, and used in the story of "Solar Plexus". It is also considered sort of a misnomer, as most of the components are above the critical point and therefore classification of liquid and gases are almost indistinguishable.

  • Critical Point: Also known as a critical state is a point under certain conditions that no phase boundaries exist.

Planets Within our Solar System

Jupiter -


("*" denotes uncertainties in research, in other words, scientific guesses)

Discovered: (2) Cosidered to have been discovered in prehistoric times and known then as the "Wandering Star." At this time however, the planet had not achieved its title as "planet," instead it was still considered a star. This changed around the 1500s when Nicolaus Copernicus arrived at the conclusion that it was indeed a planet. Alongside this, he found that the geocentric model was incorrect and offered a new idea, the heliocentric model which suggested the sun to be the center of our solar system. The first real observation of the planet however was made by Galileo, by use of his rudimentary refracting telescope.

Atmospheric Composition: (1)(4) 90% Hydrogen, and 10% Helium, (By number of atoms, 75% H , 25% He. There are also traces of methane, water, ammonia and "rock." There are a few other trace elements as well such as the gases nitrogen and sulfur, accompanied by small occurences of oxygen.

Core Composition:

Number of Moons:(3) Jupiter has 66 confirmed moons locked into its "gravity well." This gives it the title of planet with the largest number of moons ,with reasonably secure orbits within our solar system. The four most known moons however are the Galilean moons discovered in 1610 by Galileo Galilei. These moon are known as Io, Europa, Ganymede, and Callisto. These four moons are the largest objects orbiting Jupiter and make up 99.997 % of all mass orbiting the planet.

Surface Temp*: (5) The temperature in general on Jupiter is very weird as in reality the "surface" does not exist until you reach its core. At the rim of cloud cover which covers the planet are extremely cold temperatures around -150 degrees celcius. However as you inch into the planet, temperatures begin to change drastically around the "surface" as it is thought to be around 9,700 degrees celsius, this is quite the drastic change.

Core Temp*: (5) The core temperature of Jupiter is thought to be around 35,500 degrees C.

Number of Rings:(6a) 4 rings.


  • The Famous Red Spot is a slight oddity found on the planet Jupiter. Although it is an odity, it does share similarities to the other gas giants as all others have a similar spot. The spot is actually a giant storm where winds blow counter-clockwise at over 250 miles per hour. The diamter of this storm is about twice the size of earth, totaling in around 16,000 miles in diameter.

Saturn -


(! ~ Denotes contrasting research, felt it better off being blank, then being wrong.)

Discovered: (6)This fact, similar to Jupiter, is thought to be unknown as the observation of Saturn has been recorded since pre-historic times.

Atmospheric Composition: !!!!

Core Composition: !!!!!

Number of Moons: (8)(7) Saturn is thought to have 62 moons.

Surface Temp: (9) The surface temperature of Saturn is also a bit on the unsure side. Reasons for this lie on the fact that in reality Saturn has no real surface aside from it's metalic core. If however, you consider the dense layer of cloud/gas as a sort of "surface," then the temperature is thought to be around -140 degrees celcius.

Core Temp: (9) Core Temperature is thought to be around 11,700 degrees celcius.

Number of Rings: (10) Saturn is thought to have over 30 rings, though people still cannot say with certainty that more do not exist.

Oddities: (9)

  • Least Dense
  • Another interesting property of Saturn is its heat generation. At one bar, the temperature in Saturn is around 134 degrees Kelvin. This however contradicts the figures in which we have gathered from our equation for Thermal Equilibrium. With this equation, mathematicians have discerned that the "true heat" of Saturn should in fact be around the 80 degrees kelvin mark. This oddiity is explained by the fact that the gasses of Saturn are slowly dispersing from each other. With the lighter gasses rising up and the heavier falling, friction between the molecules tend to heat the gas therefore accounting for the miscalculation.

Uranus -

Discovered: (12) March 13, 1871 -- By William Herschel

Ig295 planets Uranus 02.jpg

Atmospheric Composition: (11) 83% Hydrogen, 15% Helium, and 2% Methane

Core Composition: (15) Molten Rock

Number of Moons: (13) Uranus has 27 known moons, all of which have been named after characters from the works of Shakespeare and Alexander Pope.

Surface Temp: (11)(15) -350 degrees fahrenheit is the mean temperature within the cloud layer surrounding the core of Uranus. In comparison to the other gas giants, Uranus is quite cold. This feature is explained by the fact that the core temperature is substantially lower than the others, resulting in a lower "surface temperature."

Core Temp: (15) 5000 Degrees Kelvin

Number of Rings: (12) 13 rings surround Uranus, the newest of which being discovered by hubble in 2005.

Oddities: (16)(15)

  • Uranus has an unusual tilt, this is likely caused by the fact that it's polar regions tend to take in more energy from the sun then at the equator. This would mean for this particular planet, the hottest locations would be at it's North and South poles.
  • Has a "Great Dark Spot," it as large as the diameter of earth, and is supposeably a storm system much like the Great Red Spot on Jupiter.

Neptune -


Discovered: (17) The planet was discovered in 1846. The credit of this discovery however is split between the two astromers John Couch Adams and Urbain Le Verrier.

Atmospheric Composition: (18) 80% Hydrogen, 19% Helium and methane. 1.5% CH4.

Core Composition: Mostly molten rock

Number of Moons: (19) Neptune has 13 known moons, the largest containing more than 99.5% of all mass in the orbit of Neptune.

Surface Temp: The surface of Neptune is more water than actual solid ground. However the “Surface” Temp is considered to be one of the coldest places in our solar system. Averaging at around -218 degrees celcius, the surface of Neptune is definitely a cold place.

Core Temp: The core of Neptune is around 7000 degrees Celsius, comparable to the temperature of the suns surface.

Number of Rings: Neptune has 5 rings, all of which are relatively small compared to those of Saturn.

Oddities: (18)(19)

  • The rings of Neptune have anomalies called the “Three Arcs of Neptune” , rings are unusually dense in certain areas.
  • Neptune, like its Jovian brothers, has yet another anomaly. Nesting within is the “Great Dark Spot.” This area is a depression in the atmosphere surrounded by high cirrus clouds. This spot seems to be unstable as it had disappeared from Hubble’s point of view, then was found again in Neptune’s northern hemisphere. The spot is thought to be traveling completely opposite of Neptune’s rotation at near supersonic speeds, or ten times the speed of a hurricane.
  • Fastest winds recorded in the solar system.
  • The planet itself has more water and rock than actual gas, so the title of Gas Giant is slightly misleading.

Giants from Beyond our Solar System

-- I provided this list to anyone interested in the topic of Gas Giants outside of our solarsystem. Not much information, at the moment, is known about these planets so to even make a full blown article seemed pointless at the time. Regardless, within the list, 11 and 10 are both gas giants and it seems pretty cool , though common sense denotes this to be obvious, that gas giants exist outside of our relatively small home.

Earth's Statistics - (Terra)


Discovered: (21) In today's world, the fact that our home, Earth, is known as a planet is pretty common place. This however was not always the case as it was not until the 16th century that Nicholas Copernicus shook the foundation of astronomy and shifted our point of view. It was from his ideas that the geocentric model was abolished and the heliocentric was established. From here, our home lost its title of "center of the universe," and gained the name of planet, one in which orbits our sun.

Atmospheric Composition: (22) Nitrogen (78%), Oxygen (20.9%), Argon (.9340%), Carbon Dioxide (.039445%), these are the elements that make up the largest percentile of our atmosphere. Alongside these are miniscule amounts of Neon, Helium, Methane, Krypton, Hydrogen, Nitrous Oxide, Carbon Monoxide, Xenon, Ozone, Nitrogen Dioxide, Iodine, Ammonia, and Water Vapor.

Core Composition: (23)(24) The core of earth is thought to be predominately Iron Metal. Aside fro mthis, we find that there is also a decent amount of Nickel (about 4%), alongside a light element which to this day is still under questioning. At the moment however, the argument is seemingly titlted in favor of the light element being Oxygen instead of Sulfur. In contrast, another source states that the core may consist of rare elements such as platinum and gold.

Number of Moons: Our planet has one moon, its name is Luna.

Surface Temp: (26) The average surface temperature of our planet is around 57.2 degrees Fahrenheit. This is attributed mainly to our atmosphere which acts of a makeshift blanket trapping heat beneath it. Without this "blanket," our average surface temp would be much higher and erratic weather / temperatures could be commonplace.

Core Temp: (24) The core temperature of our planet is thought to be around 5700 degrees kelvin, or roughly the same temeperature as the surface of our sun.

Number of Rings: (25) Some scientists believe that the earth could have possibly garnished rings at one point; although such a thing would have had to have occurred millions of years in our history. At this point, the earth has no rings surrounding it, however in the past humans have created an artificial ring. This artificial ring was created during a military experiment known as Project West Ford.



(1.) Basic Information - Jupiter

(2.) Discovery - Jupiter

(3.) Moons - Jupiter

(4.) Atmosphere - Jupiter

(5.) Temperature - Jupiter

(6a.) Rings - Jupiter

(6b.) Great Red Spot - Jupiter

(6c.) Discovery - Saturn

(7.) Basic Information - Saturn

(8.) Moons - Saturn

(9.) Atmosphere - Saturn

(10.) Rings - Saturn

(11.) Basic Information - Uranus

(12.) Rings - Uranus

(13.) Moons - Uranus

(14.) Temperature - Uranus

(15.) Atmosphere - Uranus

(16.) Core Temp - Uranus

(17.) Discovery - Neptune

(18.) Atmospheric Composition - Neptune

(19.) Moons - Neptune

(20.) Temperature - Neptune

(21.) Discovery - Earth

(22.) Atmosphere - Earth

(23.) Core Temperature - Earth

(24.) Core Composition - Earth

(25.) Rings - Earth

(26.) Surface Temperature - Earth

Joang94 13:39, March 19, 2012 (UTC)===