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Glau is the seventh planet from Verda and the largest world in the Verda System, as well as possibly in the entire Verda Stellar Neighborhood. As of 150 AC, it and its 494 moons are home to one of the largest concentrations of population in the entire Vernarcan Federation, due in part to the sheer number of places to put things. The largest of its moons are planetary-scale, and make up the vast majority of mass orbiting the planet. Glau's inner orbits are occupied by a uniquely impressive ring system, extending almost seven planetary radii above the clouds and shepherded by a massive number of asteroids within various gaps. Were it not for this ring system, most of the major moons would be rendered completely uninhabitable by the radiation belts which they dampen.

Glau is the third brightest natural object in the night sky of Teralla, following Esera and the star Audras, and has been observed since prehistoric times. For other civilizations in the Vernarca Nebula Seed Cluster, the effect of Glau's huge bulk was historically the first indication of any planets in orbit around Verda.

The six largest of Glau's numerous moons, in order of distance, are Eoros, Deion, Marthys, Liratan, Tarsis (with its large submoon Koro), and Velar, the last of which orbits over seven million kilometers from its parent. Liratan and Tarsis are both larger than the planet Praxis.

Physical Characteristics

Glau is widely known as being the largest planet currently known in the local stellar neighborhood. It is extremely close to being a brown dwarf, at ten standard jovian masses. A gas giant of this size is not believed to have been formed via core-accretion, but instead formed via a disk instability event, likely further out in the system than its present position. This hypothesis explains the oversized gap between Glau and Nayeren, the next planet in the system. Because of this, it likely does not have a rocky core, although rocky debris captured later in formation may have drifted to the center and formed one.

Composition

The composition of Glau is roughly 74% hydrogen and 26% helium by mass, with the upper atmosphere having much more hydrogen than the average in the planet due to helium's greater atomic weight. The atmospheric proportions of hydrogen and helium are close to the theoretical composition of the primordial solar nebula. Neon in the upper atmosphere consists of approximately 40 parts per million by mass, which is about a fifth as abundant as within Verda. Glau's helium abundance is about 95% that of the Sun due once again to the differing atomic weights making helium more common in the inner disc near the sun.

Size and mass

Glau is approximately nine times larger than Teralla, but has almost three thousand times its mass, around 9.5 times larger than every other planet in the entire Verda System combined. It is so massive that its barycenter with Verda itself lies over nine solar radii from the star's center. Glau's enormous size is often used as a measuring stick among the Ervo Sector powers to measure such things as brown dwarfs and small stars.

Despite its hydrogen/helium-dominated composition, Glau is still the densest planet in the Verda System through the power of gravitational compression. As planets increase in mass, somewhere past 2 Jovian masses they stop increasing in size and stay at around 1 Jovian radius until they start being a star. Thus, Glau has an unheard-of density of over 13 g/cm³, and any rotational oblateness is near-completely counteracted by this fact. Were Glau to increase in mass further, it would merely increase in density until it started glowing from the brief spark deuterium fusion that would eventually ignite.

Glau radiates much more heat from its surface than it receives from Verda. This is likely due to its density once again, as a lot more of the planet's primordial heat remains within the planet. At the time of its formation, Glau may have been much larger than it is today.

Internal structure

Prior to the space age, most scientists theorized that Glau coalesced around a large icy protoplanet, pulling in everything in the original disk of material nearby. This would lead to the presence of a supermassive core of up to 25 times the mass of Teralla. However, after exploration of the planet began, the complete absence of such a core was quickly noticed, so this theory was discarded.

The actual composition of Glau consists of denser and denser fluid, predominantly molecular and metallic hydrogen, increasing in pressure towards the center of the planet. There exists a diffuse "core", if one could call it that, of roughly twenty-five terrestrial masses, which mixes into the metallic hydrogen layer above it. This core was likely introduced by the impact of several smaller worlds, possibly including jovian planets in a similar size range to Jevethra.

Outside the layer of metallic hydrogen lies a transparent interior atmosphere of hydrogen. At this depth, the pressure and temperature are above molecular hydrogen's critical pressure of 1.3 MPa and critical temperature of 33 K (−240.2 °C; −400.3 °F). In this state, there are no distinct liquid and gas phases, making the hydrogen lie in a supercritical fluid state. The hydrogen and helium gas extending downward from the cloud layer gradually transitions to a liquid in deeper layers, possibly resembling something akin to an ocean of liquid hydrogen and other supercritical fluids. As depth increases, the hydrogen gradually becomes hotter and denser. Abundance of helium and neon are depleted in the upper atmosphere by precipitation of rain-like droplets of these elements through the lower atmospheric layers.

Temperature and pressure within Glau's structure steadily increase towards the core, as the enormous heat from planetary formation can only escape via convection. At a "surface" level where the pressure is 1 atm, the average temperature is roughly 380 K, as the planet is not old enough and too massive for its formation heat to escape properly by this time. The region where supercritical hydrogen changes gradually from a molecular fluid to a metallic fluid spans pressure ranges of 50–400 GPa with temperatures of 5,000–8,400 K respectively. Glau's diluted core is expected to be roughly 60,000 K.

Magnetosphere

Glau's magnetic field is the strongest of any planet in the Verda System, and among the largest in the entire Verda Stellar Neighborhood. It has a dipole moment of 14.794 gauss, tilted at an angle of 7.7 degrees off of the planet's rotational axis. The surface strength of the magnetic field varies from 6 gauss all the way up to 40 gauss in some places.

This powerful magnetic field is likely generated by eddy currents in the extremely dense inner layer of conductive metallic hydrogen. At 150 Glau radii from the planet, the magnetosphere's interaction with Verda's solar wind generates a bow shock, which can in rare cases become visible in the presence of a large enough solar flare. The solar wind interacts with the magnetosheath which lies beyond the edge of the field, elongating its shape on the far side of the planet and generating an impressive "tail" which stretches almost to the orbit of Nayeren. The largest moons of Glau all orbit within the magnetosphere, protecting them from the solar wind.

Glau's large ring system plays a unique role in the structure of the magnetic field. The metals found within its disk help magnify the size of the field, extending it well beyond Velar, but also diffusing the radiation belts that would have formed in the presence of things like the volcanoes of Eoros.

Atmosphere

Despite its awesome size, Glau has a relatively normal atmosphere for a jovian planet. Primarily composed of hydrogen and helium, it also contains smaller quantities of methane, ammonia, and water vapor present as trace gases. Active internal heating drives strong winds on the "surface" of the planet, as well as many storm systems. Glau's atmosphere extends to a depth of roughly 2,000 kilometers below the cloudtops before it stops being reasonably called an atmosphere.

Cloud layers

Glau's "surface" is perpetually covered in clouds of ammonia crystals analogous to the water-based clouds on Teralla and other M-class planets, which may contain ammonium hydrosulfide as well. These clouds are located in the tropopause layer of the planetary atmosphere, and form clearly visible bands at various latitudes, known as lighter-hued zones and darker-hued belts. These conflicting regions of wind direction and speed interact, causing great levels of turbulence and storms at their edges. Wind speeds of upwards of 350 meters per second are common in zonal jet streams, the fastest winds in the Verda System. The zones have been observed to vary in width, colour and intensity over long enough lengths of time, but they have remained stable enough for scientists to name them.

This cloud layer is approximately 40 kilometers deep and consists of a thin, clearer deck and a lower, thicker deck of ammonia crystal clouds. A thin layer of water-ice clouds underlies the ammonia clouds, initially evidenced by flashes of lightning detected in Glau's atmosphere, which generate thunderstorms in a similar way to terrestrial worlds, driven by heat rising from the interior. These discharges of electricity are over three thousand times as powerful as those seen on Teralla. Shallow lightning also originates from ammonia-water clouds high in the atmosphere, which can be clearly visible from space in ideal conditions.

The various brown colors in Glau's atmosphere are caused by the changing color of upwelling compounds after they are exposed to Verda's rays at the top of the atmosphere. These compounds are composed of a variety of phosphorous and sulfur molecules, as well as hydrocarbons. These colorful compounds then mix with the warmer clouds of the deck. The light-coloured zones between them are then formed when rising convection cells cause the ammonia they carry to crystallize and hide the chromophores from view.

Glau's low axial tilt ensures that the polar regions always receive much less solar radiation from Verda than the equatorial region does. The planet's enormous ring system is also large enough to put one half of the planet in shadow for parts of the year, which can be seen to have a bluish hue as equinox approaches. Convection within the interior of the planet as well as the leftover heat from formation ensure that cloud temperatures are similar across the planet.

Vortices

A notable feature of Glau's "surface" is a collection of persistent anticyclonic storms found at the boundaries between zones and belts. These storms have existed in various combinations for the planet's entire history of observation. These storms are visible through basic inner-system telescopes, and can be used to easily track the rotation of the planet. The maximum altitudes of these storms can be up to eleven kilometers above the surrounding cloudtops, and shadows cast upon them by the storm clouds can be seen from orbit. While any individual storm is unlikely to last longer than 20 years or so before it merges or splits apart or something, this formation is a permanent fixture of the planet and will likely remain visible for the foreseeable future.

Around the polar regions of the planet, there lie several tightly packed polar cyclone groups, with 11 on the north pole and 12 on the south pole. These regions are also where the normal belt/zone system ceases to be useful, with the atmosphere becoming a twisted mix of stormy weather.

In 489 BC, an enormous "cold spot" was discovered in Glau's thermosphere at its north pole, measuring around 29,000 km across, 13,000 km north to south, and almost 180 K colder than surrounding material. While the spot changes shape and intensity over time, it has maintained its existence, if not its position in the atmosphere, for almost 650 years since its discovery. Unlike the anticyclonic storms of the temperate zones and the polar cyclone clusters, the cold spot does not correspond to a visible cloud formation. This feature may be formed by interactions between charged particles expelled from Eoros' twisted surface and Glau's powerful magnetic field, resulting in a redistribution of temperature in the upper atmosphere.

Rings

Alongside its bulk and population, Glau is possibly best known for its vast ring system, making it instantly recognizable even through the smallest telescope. These rings extend from 7,860 to 489,377 km above the planetary surface around the equator and average approximately thirty meters in thickness. They are composed predominantly of water ice, with the inner reaches having a substantially greater quantity of silicates and metals which have a noticeable effect on the range of the planet's magnetic field. Trace amounts of tholin impurities and carbon dust are also present. Most particles which make up the rings are specks of dust, but some can range upwards of ten meters. While other gas giants in the Verda System do have ring systems, Glau's is by far the largest and most visible.

It is unclear how old the ring system is. Some believe that it formed alongside the planet from the initial solar nebula 1.9 billion years ago, or during the great heavy bombardment 100 million years later, and has remained in place ever since due to the planet's huge gravity preventing its coalescence. The other side of the debate purports that the system was formed from the destruction of a large moon, possibly several, much more recently around 250 million years ago.

Beyond the rings at a distance of 19 million kilometers lies the sparse Pisa ring. As it originates from dust expelled from the large minor moon Pisa, it is tilted at an angle of roughly 31 degrees and orbits in a retrograde fashion like its origin.

Several moons of Glau, including Amol, Thipi, and Metolo, act as shepherd moons across the ring system to confine the particles in their orbits and prevent them from spreading out. Taan and Ela cause weak, linear density waves in the ring particles near them, as well as carving gaps in the immediate vicinity of their orbits.

Orbit and Rotation

With an average distance of 4.198 AU, Glau's orbit marks the boundary between the inner and outer zones of the Verda System. It is beyond the habitable zone for water and near the inner edge of the temperate zone for several liquid hydrocarbons as evinced by Liratan. With an average orbital velocity of 14.17 km/s, it takes Glau roughly 8.87 years to complete one orbit around Verda. Glau's elliptical orbit is inclined by 3.6º from Teralla's, the reference frame for orbits around Verda. Glau is also notably the only planet to have its barycenter with Verda lie well outside the surface of the star, at over nine solar radii from Verda's center.

Glau's visible features rotate at different rates depending on latitude, and multiple rotation periods have been assigned to various regions as is often done with gas giants. On average, however, the planet rotates once ever 14.179 hours. The planet's axial tilt is approximately 19.7 degrees, substantially higher than that of Jevethra, causing significant seasons over the planet's orbit which are exacerbated by the enormous shadow of the planet's rings.

History

Formation

Initially forming from a spiral density wave in the nascent Verda System, Glau was the first planet to form around Verda. It's starting position was well past its current orbit at the frost line, and there were likely several more gas giants between it and the proto-terrestrial planets. As it migrated inward, these other gas giants were quickly devoured, bringing its mass to its present value of 10.07 Jovian masses.

By this time, a thick disk of planetesimals had coalesced around the planet, which formed upwards of five generations of moons before the precursors of the current set of seven froze out with the ignition of Verda and dissolution of the gas disk. The dust and tumbling rocks left behind were either mopped up by the nine moons or (possibly) formed the initial material for the ring system if that hypothesis is correct.

The count of moons dropped from nine to seven as three closely orbiting moons impacted upon each other, forming Tarsis. Tarsis was large enough to collect a thick atmosphere even when it was hot from formation, lending it a unique environment which persists to this day. The moon of Koro was uniquely captured into orbit, pulling Tarsis' orbit outwards by several thousand kilometers. Eoros, Deion, and Marthys settled into a 5:4:3 resonance around this time as well. Tarsis's migration also led to Velar's expulsion from the inner system, and Velar settled among the inner reaches of the growing collection of captured asteroids.

Age of the Kesstra

Initial Exploration

V'Straki Incident

Joint Colonization

Modern History

Moons

Glau has 494 known natural satellites, and there are likely more miniscule rocks that remain undiscovered. Of these, 461 are less than 10 km in diameter. The six largest moons are, in order of decreasing size, Tarsis, Liratan, Marthys, Eoros, Velar, and Deion. These moons, particularly the four largest, are clearly visible from the inner system with simple binoculars.

Tarsis

First sighted eons before any other moon of Glau, Tarsis is large enough, distant enough, and bright enough that a well-trained eye can see it from Teralla as a pinprick following Glau. Several bored astronomers wrote down a string of stars in the sky as being near Glau on such and such a day, but it wasn't until 890 BC when astronomer Gil Renae connected these observations and realized that they were the same object.

Only a couple dozen kilometers under the size of Esera, Tarsis is a moon of a size that would be unable to form around any smaller planet. Its thick atmosphere is also unique, with its heavier compounds operating under a completely different scale height than its thin hydrogen envelope. Tarsis is also unique in the Verda System for its possession of a submoon, Koro.

Isvoian Moons

The moons discovered by Tarco Isvoy – Eoros, Deion, Marthys, Liratan, and Velar – form the largest system of moons in the Verda System and nearby stars. While Tarsis was discovered centuries before the invention of the telescope, it tends to be grouped together with the Isvoian moons to avoid making the categorization unnecessarily clunky. The orbits of Eoros, Deion, and Marthys form a pattern known as an orbital resonance: in this case, for every five orbits Eoros makes, Deion makes four and Marthys makes three. The three moons thus have their orbits distorted into slightly elliptical shapes, magnifying tidal forces which work to circularize them again.

These tidal forces cause regular flexing of the moons' shapes, with Glau's gravity stretching them out as they approach and allowing them to pull back into spherical shapes as they pull away. This is seen most dramatically in the surface of Eoros, which is so tortured by these forces that frictional heat gives it the consistency of taffy, breaking open its thin crust to reveal the magma beneath at the slightest provocation, and to a lesser extent the permanent subglacial ocean of Marthys, which supports a unique superorganism and remains under quarantine. The much smaller Deion has a much more circular orbit as well, and its tidal effects – which manifested as enormous cliffs, canyons, and other such features busting up the surface – are largely set in stone.

Beyond this wild little family, the moon of Liratan hosts oceans of a variety of hydrocarbons. Its original oceans grew dramatically under the auspices of the Verna Empire after the peaceful resolution of the V'Straki Incident, followed by the foundation of the Vernarcan Federation. Beyond this lies Tarsis, and well beyond that can be found the outermost Isvoian moon, Velar, whose surface is nothing if not tortured and geologically inert.

Classification

Glau's moons have been grouped into a wide variety of boxes, based on similar physical properties and orbital elements. There are several moons, including the asteroid moon Faret and its wildly eccentric orbit, which don't fit into any boxes. Some argue that the outermost major moon Velar can't be dynamically grouped with the other five, particularly those who live there and think its cooler than it is.

Glauian Moon Groups
Regular Moons
Shepherd Moons	The inner group of shepherd moons all have diameters of less than 200 kilometers, have SMAs smaller than 500,000 km, and very low orbital inclinations (with one exception) as they work to shepherd the particles of the ring system. Their presence helps create the beautiful set of gaps that run through the system and give it its distinctive look.
Isvoian Moons	These six moons, discovered by Tarco Isvoy (except Tarsis, found centuries prior by Gil Renae by looking through records), orbit between 510,000 and 7,140,000 km from the planet and include some of the largest moons in the solar system. Velar's dynamical membership of this group is debatable, and some consider it irregular due to its higher inclination.
Companion Moons	Uniquely, Glau's major moon system is accompanied by a great number of "companion moons" – asteroids which orbit near or alongside them – which in fact outnumber the major moons themselves. These include the Eranisi group, a set of small icy ellipsoidal moons orbiting very close to Deia, and several trojan companions.
Irregular Moons
Themali Group	A small group of prograde-orbiting asteroids sharing a dynamical origin with Velar, orbiting between 7,000,000 and 7,300,000 km.
Kalao Group	A tightly clustered group of prograde-orbiting moons with orbits around 21,000,000–22,000,000 km from Glau.
Asari Group	A widely spread group of small moons with highly inclined, prograde orbits orbiting 28,000,000-29,000,000 km from Glau.
Frankla Group	A very old group, this group averages roughly 33,000,000 km from Glau and is so diffuse that it can barely be recognized as a group anymore.
Wurz Group	This group of retrograde-orbiting moons has very vague and spread-out borders, averaging 36,000,000 km from Glau and an inclination of 139 degrees.
Inanek Group	The second largest group, this tightly clustered group of retrograde-orbiting moons averages 44,807,000 km from Glau and an average inclination of 158 degrees.
Gaddis Group	Covering all the outermost moons, the Gaddis group is widely dispersed and only vaguely distinct.

@@ Line 171: / Line 171: @@
 Glau is the third brightest natural object in the night sky of [[Teralla]], following [[Esera]] and the star [[Audras]], and has been observed since prehistoric times. For other civilizations in the Vernarca Nebula Seed Cluster, the effect of Glau's huge bulk was historically the first indication of any planets in orbit around [[Verda]].
-The six largest of Glau's numerous moons, in order of distance, are [[Eoros]], [[Deion]], [[Marthys]], [[Liratan]], [[Tarsis]] (with its large submoon [[Koro]]), and [[Velar]], the last of which orbits over seven million kilometers from its parent. Liratan and Tarsis are both larger than the planet [[Praxis]].
+The six largest of Glau's numerous moons, in order of distance, are [[Eoros]], [[Deion]], [[Marthys]], [[Liratan]], [[Tarsis]] (with its large submoon [[Koro]]), and [[Velar]], the last of which orbits over seven million kilometers from its parent. Liratan and Tarsis are both larger than the planet [[Praxis (Silky Way)|Praxis]].
 == Physical Characteristics ==