Jupiter for Beginners


UWP: AF20546-8 Na Po
Type: Gas Giant
Size: Approximately 318 Earths by Mass
Gravity: 2.53 g
Surface Pressure: 20-200 kPascal (cloud layer)
Surface Composition: Liquid Metallic Hydrogen with Some Helium Atmosphere: Mostly Hydrogen (89%) and Helium (10%), with trace amounts of Ammonia, Ethane, Hydrogen Deuteride, Methane, and Water, as well as Ammonia, Ammonium Hydrosulfide, and Water Ices.
Cloud Layer Temperature: Around −125° C/-193° F.
Day: 9.9 Hours
Year: 11.86 Earth-Standard Years
Satellites: 63

The Cyclopean Giant

It is the largest planet in our solar system, so large that it is two and a half times the mass of all the other planets combined. The gas giant known as Jupiter has captured the imaginations of science fiction writers and explorers alike, with its massive satellites and giant red eye. It’s too bad for them that the reality turned out to be far less fascinating than they had hoped.

Jupiter is a gas giant that is composed primarily of hydrogen, with about a quarter of its mass also made up of helium. The atmosphere contains trace amounts of ammonia, carbon, ethane, hydrogen sulfide, methane, neon, oxygen, silicon-based compounds, sulfur, and water vapor. The planet is eternally covered with clouds that are made up of ammonia crystals, with lesser amounts of ammonium hydrosulfide.

Underneath the main cloud layer is a thin layer of water clouds, which produce lightning that is about a thousand times more powerful than any lightning on Earth. Together, the clouds are about 50 km/31 mi thick. Furthermore, wind speeds throughout the cloud layers reach up to 360 kmh/224 mph.

The atmosphere of Jupiter is further split into bands that occur at different latitudes of the planet, giving it its distinct look. However, it is at these borders where storms occur. The Great Red Spot of Jupiter is a storm that has existed since its discovery by astonomers in the 17th Century – most theorize it has existed for much longer than that. It has never, since it was first observed, shrunk in size or dissipated in any fashion. In 2000, another massive storm dubbed Red Spot Junior appeared in the southern hemisphere of the planet and has grown dramatically in size since then. It is likely to become a twin to the Great Red Spot within the next century.

The clouds are perhaps the most hospitable place on Jupiter. As one approaches the planetary core, temperature and pressure both increase steadily. While the clouds may be cold, the core is estimated to be 36,000° C/64,000° F – nearly six times the surface of the Sun – with pressures in the range of 3000-4500 GPa. Though many are extremely interested to find out what is down there, they cannot reach the core.

What is perhaps most interesting, and most dangerous, about the planet is its broad magnetic field. The four largest moons, the Galilean Moons of Callisto, Europa, Ganymede, and Io, all orbit within Jupiter’s magnetosphere. They are protected from the solar winds – but in turn subjected to intense radiation from the planet, in most cases. This magnetosphere is fourteen times stronger than the Earth’s, and the poles of the planet emit intense radio bursts that are more powerful than those of the Sun. Colonies within the magnetosphere must be shielded.

In concert with this is Jupiter’s gravity well, which draws in stellar debris as well as comets. Jupiter and its satellites receive the most comet hit of any planet in the solar system. There are those who believe that Jupiter is what protects the rest of the solar system from the bodies that float through from the Oort Cloud. The planet also boasts a small planetary ring composed of dust.

Type: Gas Giant
Size: Approximately 318 Earths by Mass
Jupiter is the first of the outer planets once one has left the orbit of Mars. Its distance from the Sun is about 5.2 times the distance from the Earth to the Sun. The chasm between Mars and Jupiter is vast.


The Jovian Gas Mines

Using the atmosphere to their advantage, two large gas mines float in the upper atmosphere of the planet. They scoop and process the gasses, sending it out to collection ships in giant containers. Both stations are operated by medium-term corporate government contractors, for use and distribution by the Unified World Council. Both are industrial facilities, with little reason for anyone not working there to visit – most workers live on Callisto and come in month-long shifts.


Type: Galilean Moon – Callisto
Size: Approximately 0.018 Earths by Mass
Gravity: 0.126 g
Surface Pressure: Negligible
Surface Composition: Silicate Rock with Water Ice
Atmosphere: Thin, Carbon Dioxide and Molecular Oxygen
Surface Temperature: Around −140° C/-230° F.
Day: 16.7 Days

The outermost of the Galilean Moons, Callisto is less influenced by Jupiter’s powerful magnetosphere than its siblings. The low radiation has made it one of the most ideal of the Jovian moons for colonization. It is the second largest Galilean Moon and the third largest moon in the solar system.

Callisto’s most distinct features are the numerous and massive impact craters that cover the surface. It appears that many of the stellar bodies lured in by Jupiter’s magnetosphere have found their way to Callisto.

The craters are from 5 km/3 mi to 100 km/62 mi in diameter, all with frosty peaks. There is no tectonic movement on Callisto, so dark plains cover the rest of the surface of the moon. The surface is part silicate rock, but mostly ice made up of water and carbon dioxide. The moon has an extremely thin atmosphere of carbon dioxide and molecular oxygen.

Beneath the surface of Callisto, more than 100 km/63 mi down, is a subsurface water ocean. This ocean is heated by radioactive material, rather than other sources, making it far less likely for life. The only colony on Callisto is named Ursa, with a population of around 80,000. It is unique among the Galilean colonies in that the city is on the surface, within a giant crater, protected by a giant dome. Since Callisto is in syncronous orbit with Jupiter, the same side faces the planet at all time – this is the side of the moon on which Ursa lies. The colony is where many of those working on other Galilean Moons live, and it is best described as a bedroom community.


Type: Galilean Moon – Europa
Size: Approximately 0.008 Earths by Mass
Gravity: 0.134 g
Surface Pressure: Negligible
Surface Composition: Silicate Rock Covered With
Water Ice
Atmosphere: Tenuous, Molecular Oxygen
Surface Temperature: Around −160° C/-260° F.
Day: 3.55 Days

The Artemis Project had already begun work on a plan to colonize Europa as far back as the 20th century, so it’s no wonder that it was the first Galilean Moon to be colonized. It is the sixth moon of Jupiter and also the sixth largest moon in the solar system.

The moon is made up of silicate rock, covered with smooth surface ice. It is one of the smoothest surfaces in the solar system. However, the surface of Europa has some very distinct features. Lineae are dark streams that run across the entire planet and can be up to 20 km/12 mi across. Some believe they are from eruptions of warm ice from below, while other believe they occur due to Jupiter’s gravitation pull. Lenticulae are domes, pits, and smooth dark spots on the crust, where warm ice breaks through the surface to make uneven patches.

However, what is most interesting about Europa is its giant underground saltwater ocean, kept warm by the magnetic influence of Jupiter. Scientists previously believed that this ocean was deep underground, when in fact it was only a few kilometers (about a mile) under the icy crust. It has conditions that resemble the deep oceans of Earth, complete with its own life and ecosphere – the first extra-terrestrial life discovered in the history of man. The lifeforms survive by chemosynthesis, similar to the black smoker environments of Earth’s seas. There is a vibrant ecosystem here, the subject of much attention.

There are three medium-sized scientific colonies on Europa – Minos, Rhadamanthus, and Sarpedon – each with a population hovering around 7000. Eachis embedded within the icy crust, about a third of the way between the surface and the ocean. Rhadamanthus and Sarpedon are both dedicated to the exploration of the alien ocean, while Minos processes all other scientific forays for the rest of Jupiter.

The colonies are shielded against the daily radiation dose of 540 rem – enough to cause serious fatal illness. Like the other Galilean Moons, Europa is locked in rotation, leaving Rhadamanthus with a view of only the stars.


Type: Galilean Moon – Ganymede
Size: Approximately 0.025 Earths by Mass
Gravity: 0.146 g
Surface Pressure: Negligible
Surface Composition: Silicate Rock Covered With
Water Ice, Small Percentage of Ammonia Ice
Atmosphere: Thin, Oxygen with Small Amounts of Atomic Hydrogen
Surface Temperature: Around −200° C/-300° F.
Day: 7.15 Days

Ganymede, like Callisto, receives low doses of radiation (only 8 rem), making it the second-most ideal Galilean Moon for colonization. It is the largest moon in the solar system, bigger in diameter though not more massive, than Mercury. It is the third Galilean moon of Jupiter.

The surface of Ganymede is composed of silicate rock, with a water ice crust. It is hardly smooth, with about a third of the planet covered in impact crater and the rest covered in grooves and ridges. There is a thin oxygen atmosphere with minor quantities of atomic hydrogen. Furthermore, it is the only satellite in the solar system that has its own magnetosphere.

It is suspected that there is a saltwater ocean nearly 200 km/124 mi beneath the surface, but scientists are too wrapped up with Europa to have explored it yet.

Ganymede has only one colony on its surface, named Troy, with 40,000 inhabitants. However, that number does not adequately reflect the number of people on the moon at any given time, for Troy’s primary trade is tourism and entertainment. It is, for lack of a better analogy, the Las Vegas of the outer planets. Visitors can enjoy the casinos, shows, and restaurants of Troy, as well as low-gravity skiing, snowboarding, and the like. The corporations that own the casinos here go through great effort to make Troy a draw. The colony has been placed so as to face it’s parent Jupiter, in a stunning view.


Type: Galilean Moon – Io
Size: Approximately 0.015 Earths by Mass
Gravity: 0.183 g
Surface Pressure: Negligible
Surface Composition: Silicate Rock with Sulfur and
Sulfur Dioxide Frost
Atmosphere: Patchy, about 90% Sulfur Dioxide
Surface Temperature: Around −160° C/-260° F.
Day: 42.5 Hours

Io is the innermost of the four Galilean moons, the fourth largest moon in the solar system. What is distinct about Io is its geological activity – it is the most active object in our solar system. There are two primary features, including mountains and volcanoes.

The surface of Io is composed primarily of silicate rock, with extensive plains coated in sulfur and sulphur dioxide frost. This covers the surface in shades of black, green, red, white, and yellow. From these plains rise more than 100 mountains, some of which are taller than Mt. Everest. They average 6 km/4 mi in height, reaching up to 10 km/11 mi. They are all tectonic structures, not volcanic, so they are stable – except for the occasional earthquake.

The volcanoes are reserved for the paterae, resembling terrestrial calderas, which dot the surface. There are more than 400 active volcanoes on Io, some producing plumes of sulfurous spray more than 500 km/311 mi high. These produce lava flows across the surface, some more than 500 km/311 miles in length.

Io, however, receives the greatest radiation of any Galilean Moon – a daily does of 3600 rem, enough to kill a person outright. This radiation constantly strips the planet of atmosphere. It’s a miracle anyone comes here at all.

However, subterranean shielded bunkers provide staging ground for those who wish to come and climb the majestic mountains of Io in a low gravity environment. It is the destination of the rich, thrillseekers, and those who already dwell in Jupiter’s orbit.

Life on Jupiter

Because of Ganymede and the traffic it brings, Jupiter doesn’t feel as far out as the other outer planets, though the colonies have their difficulties. It’s proximity to Saturn guarantees regular shipments of fresh food as well. Enclosed environments provide more than adequate shelters, and shielded vacc suits allow the intrepid to go outside. However, all the colonies face the problems associated with low gravity.

To stay healthy, colonists visit giant gravity spinners, huge structures that allow them to work out at 1G. Though all the colonies are under the aegis of the Unified World Council, they have their own unique flavors. Ursa is a quiet place. It provides everything that scientists, miners, and administrators need to survive in a modicum of comfort.

Minos, Rhadamanthus, and Sarpedon all have an atmosphere of explorationand excitement, populated only by those qualified enough to be there. Troy is a party place,where there are always new people to meet and fun things to do. Io is a place where only the daring go, holding some amazing experiences that cannot be had anywhere else in the solar system.

Jupiter for Beginners

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