1. Introduction

Commonly known as the oldest branch of science, astronomy is the most unique field of research because of how much it affects us all. While chemistry is the study of manual changes and biology is the study of autonomous changes, astronomy is the study of change we cannot control. It is also the study of the implausible theories that eventually could be proven true. There are theories about how temperature affects the vibrations of the tiniest atoms, and there are theories held about supermassive suns which can make a yellow mainstream star seem like a dot.

For most people, astronomy represents a mysterious and exciting world which covers a vast time frame of history dating billions of years into the past and back to when planets were just atoms in the darkness of space. This course will focus on celestial bodies; this is the name we give to objects like stars, planets, moons, and asteroids. The reason we call objects “celestial” is because, to our ancestors, they appeared to reside in the distant heavens.

Note that this course includes examples both “in character” (that is, from the Star Wars universe) and “out of character” (from our own universe).

Planets are formed through accretion. As a star forms, dust, particles, and gas get pulled into the star’s core and form a disc called the solar nebula. The remnants start to orbit the star and slowly build into objects called planetesimals. Gravity pulls these planetesimals to one another, but sometimes they can get caught into bigger celestial bodies. A real life example would be one of the theories about the formation of Earth’s Moon. The theory is that during the Earth’s formation, an asteroid smashed into the proto-Earth, the excess dust and particles escaped and later collided and formed the Moon we see today. The same circumstances lead to asteroid belts such as the Kuiper Belt, but the two opposing gravity fields never let the asteroids accrete into larger bodies.

2. Planet Types

Gravity is the force of attraction between two bodies with mass. The greater the mass the greater the gravitational force. This factor explains why terrestrial planets have a tendency to be closer to the Star they orbit. Heavier elements are pulled closer to the star and the lighter elements are left farther away. All the heavier elements accrete into smaller rocky terrestrial planets while lighter elements accrete into larger gas giants. Planets are considered dead when their hot molten cores are cooled and solidified. The core drives change on the surface of a planet: if the core goes cold the surface will become stagnant and remain still. The core of a planet also affects the surface of the planet, through pulling and tugging tectonic plates are forced to collide and scrape against one another and subduction zones are created. This is where the thinner and less dense crusts collide against thicker land plates and sink underneath.

Gas planets are different from terrestrial planets because they have a surface that is made up swirling gases like hydrogen, helium and ice. Being so far away from their star the temperatures can get cold enough to cool the gas particles down into a liquid form, which remains calm below its boiling point.

One of the most well known gas planets is Bespin. Bespin is a gas giant that was mined for its Tibanna gas. Tibanna was a found in the atmosphere and cultivated in Cloud City. Taloraan, Kril’Dor, and Genarius were other gas giants that Tibanna was mined from. We know gas giants as being far away from the star they orbit and have frozen surfaces the gases move across, but there are different types of gas planets. Not all gas planets are "giants", smaller sized gas planets are called gas dwarfs. Gas planets that are close to the star they orbit are called hot gas giants/dwarfs. Hot gas planets will have a much more volatile atmosphere due to the gasses being heated. Remember, the hotter something is the more its particles vibrate, creating kinetic energy.

3. Orbits

The orbit of a planet is critical to the environment seen on the surface. The two key points in a planet’s orbit is perihelion and aphelion. A planet is closest to the star at perihelion and farthest at aphelion. The common misnomer is that when a planet is at aphelion the temperature is the coldest. While there is some truth to this statement the true deciding factor to a planet’s surface temperature is direct sunlight. A planet can experience its winter at perihelion if the planet’s tilt is away at that point. The axis of rotation of a planet can change over millions of years. If the planet has a moon, its tilt will be more stable. Some planets can change their tilt so extremely that the planet’s magnetic field causes the poles to flip. The axis of the planet can vary in degrees, from zero degrees where the star remains over the equator to 90 degrees where the star hovers over one of the poles. In addition to a planet’s tilt changing over time the position in orbit can change over time as well, along with the shape of the orbit itself. A planet’s orbit can fluctuate between being more and less elliptical. Remember, all of these changes happen on time scale of tens of thousands to hundreds of thousands of years and are called Milankovitch Cycles. Sometimes all of the extremes can happen at once. A planet can be tilted away, at aphelion, and with the most elliptical orbit causing devastating ice advancing and droughts.

4. Planetary Atmospheres

Type I: Breathable - These atmospheres are breathable by most species found in the galaxy. Their compositions are primarily oxygen, nitrogen and hydrogen. Examples of planets that have Type I atmosphere are Alderaan, Coruscant, and Prakith. Granted, a species who have evolved to survive in a Type IV atmosphere will find Type I the most deadly.

Type II: Breath Mask Suggested - Dorin is example of a Type II atmosphere planet. To the Kel Dor their planet is breathable but to most the helium atmosphere is dangerous. Type II atmospheres are survivable for most species in the galaxy over short periods. Longer periods of exposure can cause harm or damage. It is not uncommon to find life on these planets, but life on these planets will have evolved to their specific environment. Sullust has two atmospheres; there is a Type II atmosphere on the surface but Type I underground. Other examples of planets that have a Type II atmosphere are Gorsh, Rordak and Torize.

Type III: Breath Mask Required - Type III atmospheres have a dangerously low level of oxygen, nitrogen and atmospheric pressure. The lack of breathable air makes these planets dangerous without life support equipment. Without a breath mask a visitor would be incapacitated and eventually die without help. Examples of planets that have a Type III atmosphere are Kessel and Korad.

Type IV: Environment Suit - Planets with Type IV atmospheres have a composition that consists of hazardous gases. These gases could be toxic, volatile, or no atmosphere at all. The chance of finding indigenous life on these planets is very rare, but not impossible. Exposure to these atmospheres without a suit will cause certain death. An example of this would be the planet Gand with its Ammonia based atmosphere. Similar to Sullust, Taloraan has a mixture of different atmospheres. At high altitudes Taloraan has a Type I atmosphere while at lower altitudes the atmosphere is a Type IV.

5. Planetary Environments

Terrestrial planets can be broken down into further subcategories based on their environments.

Agriworlds: These worlds are dedicated to the agricultural industry. Their exports will be various types of food including meats and produce. Examples of Agriworld planets would be Taanab, Broest, and Chandrila.

Aquatic: As the name implies Aquatic planets have their surfaces covered primarily in water. The inhabitants of these planets survive by either being able to breathe underwater, live in underwater cities, or cities on the surface. Examples of these planets would be Kamino, Mon Cala, and Ahch-To.

Arboreal: These planets are also known as Jungle planets. Their surfaces will be covered in dense foliage, rivers, and often have indigenous species that have high intellects. Kashyyyk, Takodana, and Dathomir are examples of Arboreal planets. Planets can share environments, for example Dathomir. On Dathomir there is "The Great Desert," but the majority of the planet is a thick dense jungle. The planet's classification stems from which environment is in the majority. That is why Dathomir is an Arboreal planet.

Desert: As the obvious name suggests, desert planets have sand covered surfaces. Examples of Desert planets would be Ryloth, Geonosis, and Tatooine. Inhabitants will be hardened by the harsh environment due to lack of water and extreme winds.

Arctic Tundra: Also known as Ice planets, Tundra planets have a frozen surface. Examples of planets with a Tundra environment are Hoth, Anteevy, and Ilum. These planets are the most uninhabited, but on planets such as Anteevy had Imperial officers living on the planet.

Swamp: Similar to Arboreal planets, Swamp planets have thick foliage. The differences come from the marshy surface below the foliage. Arboreal surfaces will be dry, while swamps will be a sea of wetlands and stagnant water. Examples would be Dagobah, Gentes, and Rishi.

Volcanic: These planets have a molten surface of lava that flow like rivers or have constant eruptions. Note, there is a difference between magma and lava. Magma is molten rock below the crust of a planet. The pressure below the surface traps gas molecules in the magma, and once on the surface the gas molecules can escape changing the chemical makeup between the two. Magma becomes lava. Examples of Volcanic planets are Mustafar, Sullust and Lola Sayu.

6. Conclusion

Planets are shaped by their orbit and location in a star system. Stars and planets might have similarities but no two are identical. We know the fuel the stars run on, differences between planetary surfaces, and differences between planet classifications. It is important to know the planet before it's too late to do anything about it. Once on the surface your fate might already be sealed without you even knowing it, but the same could be said about your enemy if you know how to use the battlefield as an additional weapon in your arsenal.

7. Dark Jedi Brotherhood Systems

Here are the Clans and their base planetary systems.Clan Plagueis uses The Anchorage as their headquarters. The Anchorage is a starbase currently located in the Sith controlled Esstran Sector.

Antei - Brotherhood Citadel: Noted as the first planet from the sun of the Antei system, Antei is an arid planet currently comprised totally of deserts, mountains and the relics of history and the Brotherhood. Antei has a fairly balanced day and year cycle, it takes 24 hours to turn on its axis and 365 days to orbit the sun. Because of its bountiful mountain ranges, quarries are dotted across the surfaces to mine Cortosis and Electrum. The only major import when this planet was used, is the high desire for edible cargo and soluble fluids. Most recently the surface of the planet has experienced super-massive shockwaves of heat and sound, causing buildings to be raised and the sands glassed. We would now rate this planet as Type IV due to the unknown dangers presented through the Force.

Judecca - Seat of Clan Scholae Palatinae: As the second planet from the sun in the Cocytus system, Judecca is a symbol of a surplus of life and a strong molten core. Jungles blanket the surface of every continent and mountains are pushed into the skies, causing certain patches of jungles to be isolated and grow independently. Judecca is slightly smaller than a preferred planet size, and this speeds the day cycle to 27 hours and the orbit of the sun to 344 days. The most important exports of the planet is artefacts, exotic items and education of history. It is clear a lot of civilisations when colonising this planet lose their connection to others off-planet. This isolates their temples and operational bases, the jungle grows over them and explorers come along to find them preserved. Judecca is a type I planet.

Karufr - Seat of Clan Taldryan: Fourth planet from the orbit of the Kr’Tal sun, Karufr is a perfect planet to habituate and colonise, with a terrestrial surface and vast oceans. The molten core makes three very large continents to form and lush forests to grow. As one of the smaller Clan planets, its day cycle is a quick 21 hours but the yearly orbit has extended to 389 days. The unusual orbit is caused by its distance from the sun, and its small gravitational pull. It is vital to note that the oceans on this planet are perfectly habitable for many species like Nautolans and Mon Calamari. Karufr is a type I planet.

Kiast - Seat of Clan Odan-Urr: Nestled as the second planet from the Kiast system binary suns, Kiast is also a peculiar gas giant. Not too hot nor too cold. This planet is also another unusual orbiter, as its day cycle is lengthened into 24 hours, and its yearly orbit an extended 426 days. One theory suggests that when created, the binary subdwarf system it formed in, developed Kiast under high gravitational pressure from its parent stars into a small, but an active tectonic planet. Its revolution is an imperfect ellipse, rather than a circle, which creates a very unique effect on the planet surface. Its proximity to the binary star, coupled with its irregular orbital path, has a straining effect on its tectonics as the planet is constantly pulled and pushed against the gravitational forces of the stars. Formed to hold both Type I and Type IV atmospheres, its surface it covered in a thick concoction of Helium, Hydrogen and Tibanna Gas. The denizens use hovering cities above the clouds to live.

Selen - Seat of Clan Arcona: Sitting in the outer orbit of the Dajorra sun, Selen is a sparse planet covered with giant oceans and scattered with small and lush islands. The planet is gigantic compared to other Clan planets, with a calm 28 hour day cycle and a sluggish 454 year orbit, the distance from the sun creates a slow orbit for the moon as well. Due to the nature of the Selenians being social hermits, they refuse help from others, exporting only weapons and credits. Selen is a type I planet.

Sepros - Seat of Clan Naga Sadow: Known as an oddity in the Brotherhood, Sepros is a twin planet located fourth from the Orian sun. Many scientists believed that Gamuslag was the moon of Sepros, yet they found the two shared a central mass and share the year orbit of 470 days. Due to their close proximity Sepros has a 36 hour day cycle, despite being slightly smaller than the average habitable planet diameter. Sepros has no exports or imports since all of the minerals ran dry millennia before. Sepros is a type I planet.

Yridia II - Seat of Clan Tarentum: Noted as the only aquatic planet represented by a Clan, Yridia II is the second planet from Yridiae. It is a very unique planet because less than 1% of the surface are islands above sea level; these are used for farming. History indicates the planet used to have continents when it was much cooler, however due to the growth of the sun, the polar ice caps melted and submerged much of the land. With a large diameter, is it logical for the planet to have a 27 hour day cycle and the yearly orbit stays at around 344 days. A large majority of the population are aquatic races and use their abilities to live underwater and farm food there, while terrestrial races farm on the islands. This is a type I planet.