The Solar System
by: Gn. Dionysius Draco Invictus
A brief overview
The ancient Romans and Greeks deemed natural science, especially astronomy, a form of art. To a modern audience this sounds peculiar, as people usually associate science – and the astronomical sciences in particular – with dry, mathematical research, funny smelling labs, computers, an occasional madman and whatnot. However, to the ancients the light that the stars emitted, the orbits the planets described and the very matter we were all composed of, as an integral part of existence, must have had something strangely magical and poetic. In order to revive and revaluate this tradition, I have tried to write a series of short essays on the most important bodies in our solar system. I hope you will like them, and I appreciate any form of comment or criticism on the SVR Forum.
In honour of the Muse Urania,
Gnaeus Dionysius Draco
The Sun is by far the largest body in the solar system, and probably originated about 5 billion years ago from what is called a stellar nebula, a.k.a. dense concentrations of gas, mostly hydrogen. The true process of how a star is born is still unknown to scientists, but the idea is that due to the pressure in the core of the accretion disk (i.e. the further you distance yourself from the core, the fewer particles there'll be), nuclear fusion starts, marking the beginning of a star's life. Some stars are large, bright and fuse their gas supplies quickly, while others are small stars that have little needs (cosmically speaking, that is, of course). Our Sun is a G2, a pretty normal star in its main phase. About one out of two star systems has more than one star, but ours luckily has only one. More about the why of this in Pars Quarta on planet Terra.
98% of all mass in the solar system is the Sun, to give you an idea of its magnitude compared to its children. On the surface (although "surface" is a strange term considering it's probably closer to "solid gas granula" than a solid surface), temperatures are probably as hot as in Terra's core, about 5000°C. There are cooler spots as well, black of colour, and these sunspots change places randomly.
The Sun's heliosphere reaches 1,5 times past the orbit of Pluto, and the solar winds would probably kill us with deadly radiation if Terra did not possess an ozone layer.
An interesting scientific theory is that about the magnetic pole switch of the Sun. It says that periodically, the magnetic poles of the Sun switch from north to south. This would be accompanied by very strong outbursts of radiation, and would also impact the magnetic fields of the planets (supposed they have one). It is evident such a phenomenon exists, as is proven by depth research in the Atlantic Ocean, which shows that magnetic rocks can have a different magnetic orientation than we have today. The question is, when does this happen? It's not sure. The research in the Atlantic seems to show that it happens pretty randomly, say once in a few million years. Other scientists and pseudo-scientists claim it happens once in 11 thousand years. Such a pole flip would be responsible for the death of Atlantis and the last flood that ended the Ice Age. No one knows when the next time will be. 2012 is often mentioned, but it's for certain that the moment cannot be far off (shown by the Atlantic research), although no one knows what exactly it does. Some even claim it has already started, causing the multitude of Terraquakes of the past three years all around the world.
Mythologically / Symbolically
The Sun has always been the symbol for life as such, and was worshipped as an important, if not the most important, deity by many people. In some cultures, like the early American ones, this was accompanied by the infamous blood sacrifice, while in Egypt some pharaohs identified themselves with the Sun. The most common gender attributed to the Sun is male, as opposed to the Moon being female.
In ancient Rome there was, of course, the cult of Sol Invictus, that might have had its root in earlier Indo-Germanic traditions. Even in modern times the symbol of the Sun for energy, life (but also vengeance, fire and blood) is still being used by many companies and even political ideologies. For example, the swastika is nothing more than a solar symbol. Of course, many artistic schools and genres have also been influenced by the Sun, or made it a theme of their works.
In astrology, the Sun is linked with gold, and is the celestial domain of Leo. It symbolizes power, richess and dominance.
At first sight, Mercury looks like a small, dull planet which resembles our own Moon a lot. It's the second smallest planet of the solar system, is cratered, and its surface is greyish of colour. Also, the planet does not bear an atmosphere of any significance and has probably no tectonic activities.
However, a closer look learns that Mercury isn't as dull as some would like to believe. The most astonishing fact of this little planet is the presence of a magnetosphere, which was clearly shown by the instruments of the Mariner 10 probe (the only one to ever visit the planet so far). This magnetosphere is probably caused by the fact that Mercury has, in relation to its mass and size, a huge core, most likely iron.
Another interesting feature on Mercury is the Caloris basin near the south pole. Scientists believe that this basin, which looks like a grotesque ocean with solid waves, was created by a massive impact of an object on the other side of the planet in its early days, when there was much more natural "space trash" then there is now. Certainly Mercury had some big blows in its childhood, and as there is no erosion on the planet, the scars are still visible today.
Temperature on the planet during the day may rise to 400°C, hot enough to melt lead, although the night is of course much colder. It's still not the hottest planet in the solar system, though, but that is a concern for later. Some (pseudo-scientists) have also suggested the existence of a planet called Vulcan, which would have its orbit between Mercury and the Sun. There has been some search for this hypothetical planet, but none was found.
The approximate distance from the Sun to Mercury itself is about 58 million kilometres. A year lasts 88 Terra days, and one day takes 59 Terra days to complete. Earlier theories about Mercury contended that it always presented the same side to the Sun, but it clearly isn't so - others have said that if this were so, Mercury would have exploded due to the massive difference in temperature. An astonishing fact is that two days on Mercury last longer than one year. In a scientific essay of his Isaac Asimov suggested that this could cause an observer on Mercury to see two suns at once, due to the difference between the length of a day and the length of a year.
Mythologically / Symbolically
Of course, Mercury was, in ancient times, Mercurius (or Hermes in Hellas). Mercurius was the God of merchants, messengers, travellers and... thieves. He was usually depicted as a young man with a staff and the typical winged sandals. The association with Mercury's true speed is of course obvious, as Mercurius was the messenger of the Gods (but also often Iuppiter's personal henchman). Especially in ancient Celtic religions the deity which was associated with Roman Mercurius (or Mars) had a lot of prestige.
In western astrology, Mercury is linked with the signs Gemini and Virgo, and symbolizes intellect, wit, speed and communication. Its element is quicksilver.
In ancient times, until fifty years ago, Venus was often referred to as Terra's twin sister. It had about the same size, and of all planets Venus stood the closest to Terra. Many speculated Venus' thick mantle of clouds could hide planetary oceans, or tropical forests and other exotic lifeforms. The reason why Mars had always been much more popular to speculate about life than Venus was because of those very clouds. They make Venus impenetrable for any sort of telescope.
When both American and Soviet (especially Soviet) probes were sent to Venus, we learnt of a whole different truth. The thick yellow-white sphere of clouds that covered the surface hid a world that seemed remarkably close to medieval descriptions of hell. Temperature at the surface ran up to 500 °C (which is hotter than Mercurius, despite the fact that it's closer to the Sun), the pressure was about 97 thousand millibars (compare Terra with an average pressure of about a thousand millibar), there was a constant rain of sulfur oxide, its atmosphere consisted of pure poisonous carbon dioxide, and the surface was dry, covered with burst rocks and grey volcanic sands. The Russian Venera probes lasted only a few minutes, some only a few seconds, on the planetary surface. Later observations, by the American Magellan probe in the early '90s, showed that the planet had a pretty recent volcanic past. Lava channels ran through the surface, and there were clearly volcano calderas visible, not to mention "pancakes", comparable qua sight to the Martian shield volcanoes. Scientists don't know if Venus is still geologically active today, but most suspect it is.
As of today, it's still unknown what caused this almost surrealistic situation on Venus. Like Terra and Mars, Venus must have had water in the beginning. A popular theory states that in its early days, the planet must have had warm oceans of about 70° or 80° C. However, due to the water damp, a greenhouse effect was initiated. The result of a slowly rising temperature was that the temperature of the water kept rising, resulting in turn in a higher level of water damp, until a level was reached where all the water was gone. The atmosphere, strongly fed by volcanic outbursts, had gotten so thick that many forms of radiance and heat could not escape the planet. And so we see today these infernal marks of suffocation.
It's the only planet in the solar system that moves retrograde. It completes a year in 243 days. It's unknown how long the day lasts, but some believe it to be even longer than its year, due to the absence of a magnetic field. It's for certain that Venus' winds spin faster around the planet than the planet spins its day.
But aren't there any resemblances to Terra? Yes, there are. For instance, the geological profile looks a little like Terra's, with lowlands, mountain ranges and "island chains". Also, it's believed Venus' inner structure resembles that of Terra a lot. It's a little smaller than our blue planet, but still equals Terra much more than any other planet, talking about proportions and sizes: Terra's very own evil twin.
Mythologically / Symbolically
The name Venus is not a coincidence. It was associated with the goddess of love and beauty because it shone very brightly in the morning sky and the evening sky. Some cultures even thought the Morning Star and the Evening Star were two seperate celestial bodies. However, it's clear that Venus has always been given a positive significance. Its shining beauty was inspiring. It stands for love in its broadest sense.
As a symbol, Venus is not only associated with love, but also friendship, durability, happiness, health, marriage, frivolity, sex, physical aspects of life and (material) fertility. In the western Zodiac, Venus is associated with Taurus.
In many ways, Terra is a special planet in the solar system. Geologically, it's the most active planet of the inner planets, and it's also the largest (even though Venus comes close). It's the only planet with an atmosphere that consists of so much oxygen (about 20%), which is largely due to the lifeforms that inhabit its surface. Terra lies about 150 million kilometres away from the Sun, and is the third planet in the solar system. It completes a day in 24 hours and completes an orbit in 365,25 days. Due to its slightly diagonal axis, it has seasons.
Other things that make our Terra so worthwhile and precious are the presence of water in a liquid state (and in gigantic masses) on the surface, and the presence of a disproportionally large sattelite, compared to other planets. The Moon is among the largest moons in the solar system, and comes close to the size of Mercury. Most modern scientific theories hold that Luna originated when, in the proto-solar system, a large object, about the size of Mars (1/2 Terra) hit the young Terra severely, and that the material which was slung away formed the Moon, due to the melting heat. This impact heat would also explain the absence of water on Luna, plus the structural similarities between Terra and Moon (but also some remarkable differences). Luna itself is a dead, dusty world. Its surface is very old and cratered, and was once overrun by magma streams (probably in the beginning of its existence), which cooled off shortly after. Their footsteps would be later known as the maria or "seas", the darker spots on the Moon. Scientists don't know yet why there are more maria on the side that's always turned to Terra than the other side.
Even with the Moon put aside, Terra remains a spectacular world because of what makes it so special: the visible presence of life. Scientists believe life originated about 3 billion years ago, in a highly volcanic climate. The actual "first life" is still an enigma, but it had something to do with organic acids, and electric reactions. Whatever the case may be, for the first aeons, the only life Terra knew were primitive one-cell-creatures and bacteria. Later these evolved into sea plants, and about half a billion year ago the first fish appeared. After that, life started to crawl onto Terra's landmasses, first the vegetation, later the animal life. This was the era of the dinosaurs, wiped out 65 million years ago by what was probably a comet impact. This made it possible for the class of mammals to develop, and eventually, about 3 million years ago, the human race originated. One of those very humans who is now writing this.
Terra lies within the so-called "ecosphere", the zone that is far and close enough from and to a star to make life originate. Such a zone is, according to exobiologists, only possible for a certain class of stars, to which our sun belongs (ideally the G class). This ecosphere begins not very far ahead of Terra's orbit, and reaches a little past Mars'.
Mythologically / Symbolically
Many primitive cultures worshipped a Terra Goddess, before this cult was replaced by that of a sky god (Ouranus, Iuppiter, Zeus, Ahura Mazda, Varuna...). Ancient depictions of this deified Terra have been preserved. Usually the planet Terra is a symbol for fertility, life in total, cycles, but also for humility and vulnerability, all meanings that modern "green" adepts tend to use.
In classical astrology, Terra was not considered a planet, but the Moon was considered an opposite of the Sun. Whereas the Sun stood for male dominance, the Moon stood for female intuition. Even now the Moon is most linked with dreams, night, intuition, femality and the female cycle, comparable with the Taoist yin force. Luna is the "planet" of Cancer.
Mars is the fourth planet from the Sun, and marks the borderline of the inner solar system. Beyond the orbit of Mars everything is disproportionally small or large, starting with the planetoid belt, followed suit by the four gigantic Jovian planets, finally ending with the Kuiper belt, filled with dark and icy bodies.
However, Mars is one of the most intresting planets in the solar system. It's about half the size of Terra, and one of its neighbours. As observations by many Martian probes have shown, it is a cratered and dusty world; but just like Terra, it features deserts, cracks, poles, ice caps, seasons, canyons, plains, volcanoes and... water. Sadly enough, this water is frozen, and resides under the planet's crust under the form of permafrost, or on the poles, in combination with dry carbon dioxide-ice. Speaking of carbon dioxide, this element makes up about 90% of the Martian atmosphere, which is very thin - only about 5 millibar. A Martian year lasts 687 days, which is about the equivalent of two Terra years, and the Martian day is just a little longer than the Terra day. Speaking generally, the average temperature is about -30°C.
Mars has two of the most astonishing geographical features in the solar system. First, there's the Tharsis plateau, which is volcanic in origin, and rises up about 10 kilometres above the rest of the surface. Some scientists say this rise was caused by an impact on the other side of the planet. The crater of that impact would be the remarkably deep Hellas Planitia. Whatever the case may be, the Tharsis plateau was highly volcanic (it is probably dead today), causing three large shield volcanoes in existence, of which the most famous is Olympus Mons, the largest mountain in the solar system. All in all this volcano is 26 kilometres high (meaning about three times the height of Mount Everest), and its base is over 300 kilometres wide, making it as broad as a small European country. The second remarkable geographical feature is the Valles Marineris, a giant canyon, named after the Mariner 4 probe. No one knows how deep it really goes but it may very well be more than 10 kilometres deep, making it as deep if not deeper than the Mariana depths in the northern Pacific. It's so long that if it would run through North America, it could cover the US from east to west.
The thing that makes Mars so very exciting, however, is the existence of water. Whereas Mercurius and Venus are dry, hot worlds, Mars is a frozen world. It hasn't always been like that. About 500 million years ago, scientists reckon, the atmosphere must have been much thicker, and water ran freely across the surface - hence the many dried up "rivers", which are still visible upon close observation of the Martian surface. So it is not unlikely to suppose that Mars once held life, and may still hold life under some form today. Evidence (such as the infamous Martian meteorite found on Antarctica) points towards the direction that there has been life on Mars, but whether it still exists today is highly doubted. The experiments of the Viking probes and the Mars Sojourner neither confirmed nor denied the existence of life. It may be, but it may very well not be.
If the human race is ever to expand in outer space, Mars is the planet that is most likely to be colonised as a first extraterrestial world. Optimists speak of "terraforming" the planet, id est to make it hospitable for Terra lifeforms, and eventually man himself. This process would involve genetically manipulated plants that breathe carbon dioxide, are able to survive the drought of the planet, and exhale oxygen. Another option would be to send ice meteors to the Martian surface, adding to the Martian water supply. The real problem, however, is the density of the atmosphere.
Mars has two moons, discovered in 1877 by Asaph Hall. These moons' names are Phobos and Deimos (Anguish and Fear), and are captured planetoids. They are small, dark and cratered worlds. In 40 million years, Phobos will, due to its orbit, crash onto the Martian surface.
Mythologically / Symbolically
Mars has always been associated with battle and war. Ares for the Greeks, and Mars for the Romans; this association was due to its bright red colour, and a bright Mars, so the Roman people believed, was an omen for a plague or a bloody war (comets were even more so seen as messengers of disaster). Another thing Mars has been associated with, and still is, is manly power, dominance, force, impulse, male passion and anger.
In the modern western astrology, Mars is the planet associated with Aries.
Another thing that might be worth mentioning are the urban myths that surround Mars. According to some, the first base on Mars had already been set up by the Americans in 1984 (and those same people say the Germans landed on the Moon in 1948), and its moon Phobos would be an artificial satellite, due to its strange yet smooth shape (adding to this mystery is the Russian Phobos probe which, after landing on the Moon successfully, was cut off from Baikunur, never to be heard from again). Older myths tell of Martian canals, first seen in 1877, but later proven to be nonexistent.
Especially in the decades before the first actual close-up photographs, things like War of the Worlds were immensely popular. Truly modern myths, however, tell about the Face of Mars, a rock in Cydonia Terra that looks like a human face, but which, according to recent photos, proved to be just a coincidence (opponents say this photo is a fake, of course). In that same Cydonia Terra area, there would be supposedly pyramids, built by a prehuman civilization that would also be responsible for the Egyptian and the South American pyramids. So as everyone can clearly see, Mars' myth is far from finished.
According to 18th century scientists' calculatons, there was enough space between the orbits of Mars and Iuppiter to contain another planet, and furthermore, mathematical rules and calculations showed it was very likely that there was one. But why wasn't it visible then? Some assumed it was too dark to be seen with the 'naked eye'. That's why astronomers went on a frantic search with telescopes.
In 1802, Ceres was found, and immediately assumed to be the 'missing planet'. However, it was very small, and shortly afer its discovery, other 'planetoids' were found. While the planetoids first discovered had the size of middle-large moons, the ones discovered later were really tiny, and had irregular shapes.
A popular belief held that these planetoids were shards of a planet that had exploded due to the gravitational workings between Mars and Iuppiter, that were too strong for the planet to exist. However, calculations showed that the combined mass of all these planetoids was barely enough to make a reasonable planet with. Thus, today, most scientists assume that the planetoids have always been more or less this way, and that it was this gravitational force that prevented them from forming something planet-like. Over the millions of years, many planetoids got captured by Mars or Iuppiter, crashed onto other planets (or into each other), or had gotten irregular orbits.
Mythologically / Symbolically
As the ancients did not yet know of the planetoids, any symbolical meaning given to them came after their discovery. And as of yet, they haven't been given a clear role in preternatural disciplines such as astrology, symbolism or esotery.
Regarding urban myths, however, planetoids are pretty popular in science fiction. They are seen as 'space isles', mostly bases of space pirates or platforms comparable to oil derrecks in the Terra oceans, because it is believed many planetoids hold valuable minerals or rare metals. A more violent aspect of planetoids in science fiction is their bizarre nature and their possible (and equally bizarre) inhabitants, or their likelihood of being used as projectiles in terrible space wars.
Iuppiter is the biggest planet in the solar system. Terra would fit into it about 300 times, and its impressive collection of moons alone makes is some sort of small solar system on its own. Iuppiter is also one of the planets that is being said not to be a real planet (along with Pluto, although for another reason). Some scientists claim that Iuppiter is a brown dwarf, id est, a star that failed to become a star, because it could not produce enough pressure and/or energy to begin a thermonuclear reaction, which is the start of a star's life. Actually, we are lucky that Iuppiter did not become a star, because we might not be existing today if we were caught in between two suns. One of the arguments scientists base themselves upon is the discovery of other Iuppiter-like planets with other stars, only they are much bigger than Iuppiter (from 1,5 to 30 times its size), making them certified brown dwarves. So it's a common appearance. However, the most important argument is that Iuppiter actually radiates more energy than it receives from the Sun. The only other planet who shows the same pattern is Saturnus -- and guess what, Saturnus is the second biggest planet.
Iuppiter is, as far as the definition of planet applies, a gas planet. That means there is no concrete surface to touch upon. Its atmosphere gradually becomes thicker and thicker, until you get a high-pressure liquid sea of hydrogen. Some say that its core would be pure diamond, as its core is probably highly pressurized. Anyway, apart from this speculation, the upper atmospheric layers, being the only ones we can see, are still quite spectacular. They offer us a sight at Iuppiter's 9-hour rotation, and make clear that the word "stormy" would be a euphimism for Iuppiter. Its biggest storm, aka the Great Red Spot, is actually a storm raging on there for about 300 years (and that's as far as we have documented). Another speculation is the possibility of life in the Iovian atmosphere. Theoretically, it could exist, on a place with a moderated pressure and the right atmospheric circumstances. This idea has been used by Arthur C. Clarke in his Space Odyssey series, a famous science fiction classic.
The moons also form an interesting bunch. Most of them are captured planetoids, or irregulary shaped objects, but four of them actually resemble small, rocky planets. They were discovered by Galileo. It gave him the inspiration for his heliocentric model for which he would be thrown in prison by the Church.
All of Iuppiter's moons are named after his mistresses. Only Hera, his true wife, has no moon named after her. The first one (closest to Iuppiter), Io, is a small world that would seem like hell to us. A very thin atmosphere of sulfur, constant volcanic eruptions, and above that surface, nothing but icy cold. Due to the constant flow of lava and other magmatic materials over Io's surface, drawing a map would be impossible, because within a few decades Io's surface would have changed again. But how did it become this liquifying hell? Most likely due to the proximity of Iuppiter's magnetic field. The planet has a very big magnetic field (which is deadly to terran lifeforms, by the way) that reaches even past the orbit of Saturnus (which is 1,5 times as far away from the Sun!), so it's not unlikely that it exercises such an unnaturally great influence on its moons, especially when they are made out of rock, like Io.
The next moon would be Europa. Its surface seems smooth, but once you come to think about it, is very suspicious. A world with no atmosphere, without any scars? If we look closer, we do see them, but they are relatively young, in the form of what appear to be dark canyons and cracks - that is so, because Europa's surface consists of ice! The cracks and canyons, that appear and then disappear, are also probably due to Iuppiter's magnetic influence. But there is a very exciting possibility, namely that of a gigantic ocean benath the icy surface. And water might mean life.
The next moon taken into consideration is Callisto. It's a cratered world, larger than its two brothers, and appears to be ice-covered in some places, but consisting mainly of dark rocks. However, being a relatively more stable world than Io or Europa, this is a good world to exploit in later space adventures because of the ice present, and the proximity of the other moons. Not to mention the magnificent sight of Iuppiter.
Finally, the last of the four big Iovian moons is Ganymedes, the largest in the solar system, larger than the planets Mercurius and Pluto. Despite its impressive statistics, it is a quite boring world. Even its craters seem to be regular, and there are no maria like our moon.
Iuppiter possesses a whole family of other moons, most of them captured planetoids, and not as interesting as the four large satellites. They are usually irregular in shape, and very small.
Iuppiter completes a year in 10 of our years, and has a small, nearly invisible ring, probably made of carbon fragments. It has been visited by Pioneers 10 and 11, Voyagers 1 and 2, and most recently, in 1996, by the Galileo probe, that actually dove into Iuppiter's atmosphere.
Mythologically / Symbolically
As all of you will know, Iuppiter is the ruler of all gods (and quite a good choice, since his planet is the biggest of all). In ancient times it was known as the fifth planet, and as far as I know no utterly special importance was attached to it (in contrast to Mars and Venus).
In astrology, Iuppiter represents the star sign Sagittarius (the Archer). While it stands for magnaminity, understanding, sage rulership and success, it also stands for superficiality and empty impulse.
Next to Mars, Saturnus is perhaps one of the best known planets in the solar system, in contrast to relatively boring worlds such as Mercurius. Saturnus' popularity is of course due to its feature that characterizes the planet so: its rings! Although all Jovian giants have rings, Saturnus has the most remarkable set of them, which can even be spotted with a simple telescope. Astronomers thought of the planet's rings as "ears" (as can be seen in drawings made during observations by the 16th century astronomer Huygens), and only later the term "rings" became the common expression. More about them below.
The planet itself looks kind of featureless and inaccessible at first sight. A beige-brown colour that appears all over the atmospheric surface, and no clearly visible magnificent turbulences and storms as seen in Jupiter. However, that doesn't mean that Saturnus is a quiet gas planet (in fact no gas planet is really quiet). It has similar winds raging in its vast cloud realm, and also appears to be radiating more energy than it receives from the Sun. Saturnus is also significantly flatter than most other planets, id est, the difference between the polar diameter and the equatorial diameter is higher than on any other planet. Its mass equates to about 95 times that of the Earth, although if there existed a body of water large enough to wash the solar system in, Saturnus is the only planet that would float on the water, as its density is 0,69 (with water having density 1). For a comparison: Earth, having the highest density, has one of 5,52. Similar to Jupiter, its chemical composition consists mainly of helium and hydrogen. Saturnus completes a day in nearly eleven hours, and completes an orbit around the sun in 29,5 years.
Another thing Saturnus is known for, like the impressive rural god of old, is its vast empire of moons (about 20). There are regular, "typical" spheroid moons, and irregulary shaped moons (of which the largest part float in the rings). Most of them are named after the titans of old, who rose to power in the kingdom of the gods, but were slain and banished to Tartaros. A moon that really stands out from the crowd, however, is Titan. It's the second largest moon of the solar system, but that's not the reason why it is so exciting. The reason for that excitement is the fact that it has its own, well-developed atmosphere! Other than the very thin to non-existent atmospheres of other moons, this is a clearly present one, even so present that our telescopes are unable to peer through it; a similar problem that was encountered when observing Venus through a telescope.
Astrochemists have learnt from their spectral and other research, that Titan's atmospheric conditions are quite similar to the conditions on Earth about 4 billion years ago, when life originated, which in turn let to several hypotheses that primitive bacterial or viral life - or at least the necessary acid chains - may exist on Titan. To examine this without doubt fascinating world, a probe named Cassini will arrive at Saturnus in 2004, and drop the smaller probe Huygens into the unknown regions of Titan. Cassini caused quite a stir during its launch, as it had a dangerous amount of radioactive material aboard. Should the launch have failed, or should something have gone wrong during its return to Earth to gain more speed, we'd have been showered in radioactivity.
Other prominent moons of Saturnus include Mimas, a small world with a crater that nearly covers a full hemisphere. It's a miracle that the small moon was able to survive such an impact and is still spheroid in shape. Another strange bird is Enceladus, that looks a lot like Jupiter's ice moon Europa, but is even smoother and does not show the same pattern of cracks and lines, possibly due to the lesser magnetical force the planet exercises in comparison to the ruler of the planets. A truly bizarre world, however, is Iapetus. On one side, it's a dark, most likely carbon-based moon, but its other side has a much higher albedo (light reflecting value). Nobody knows why.
The rings are a different story. In the second half of this century, we got confirmation about the material which the rings were made of: small rock and dust particles that appear like one solid ring from a distance. They follow regular orbits, and probably keep together because of their intergravitational forces (comparable to the planetoids, but simply smaller). The most popular theory about the origin of the rings says that they are remnants of a shattered moon that came too close to Saturnus, and was torn a part by the gravitational workings involved. However, in the middle of those rings, a few smaller moons (called shepherd moons) are still alive and well, so it is far from sure that the rings did evolve from a shattered moon (or protoplanet).
Saturnus has been visited by Pioneer 11, Voyager 1 and Voyager 2.
Mythologically / Symbolically
As most people know, Saturnus (Chronos) was the father of Iuppiter (Zeus), who slew his own father, Uranus, to gain control over the world. Being the god of time and prosperity, he wanted to establish an eternal kingdom, but was so deadly afraid of the oracle that predicted his own downfall at the hands of his children, that he ate each one of them. Rhea, his wife, however, hid Iuppiter from him, and wrapped a big rock in a towel instead. Saturnus ate the rock, and Iuppiter grew up in the mountains, only to return one day and in turn overthrow his father, forcing him to throw his elder brothers and sisters up, effectively ending his reign.
Despite that violent - and moralizing - story, the Romans usually associated the Saturnian age with a time of peace, order and justice. It is a funny coincidence (or not?) that gold (or brown) the colour that is usually accorded to Saturnus, is also the colour of the planet! Being a rural god, he is invoked for fertility, but also for financial welfare.
Everyone who has seen a picture of Uranus usually admits that the planet has something eerie. Something very disturbing and cold. This is because of its green-blue North Sea colour, which is equally spread all over the planet, and is nowhere broken by different cloud belts or weather patterns, as in the atmospheric surface of Jupiter and Saturnus, who are also, like Uranus, gas planets. Its atmosphere consists mainly of hydrogen and various ices, which appear to be evenly distributed all around the planet, hence the smooth equality in colour.
Since eeriness cannot be measured in science, the planet appears to be a very boring world at first sight. It has a largish family of moons, most of them dark and ugly, and a set of rings, which have been observed through the obstruction of starlight that passed by Uranus' rings. However, what the eye cannot see, is that the planet is actually hanging in space as if it had flipped aside, making its magnetic poles the equator, and transforming the equatorial line in the Uranian version of the Greenwich Meridian. While most planets have some discrepancy between their geographical and magnetic poles, the difference is really huge in Uranus' case. Nobody knows why this is so. Some scientists have suggested that in its early history, the planet collided with another proto-planet or an object of a large size, which made the planet "fall over".
Uranus' system of moons becomes interesting when you look closer. All of them are named after characters used by Shakespeare and Pope, and the most famous of the Uranian moons is probably Miranda. This tiny, dark world looks as if it has been put together by the surrealist painter Dalì. Despite its spheroid form, the cracks, canyons and craters are so edgy and deep that they have an impact on the moon's shape. It has been assumed that Miranda was once blown apart by an impact, but later "melted together" again by some mysterious circumstance. Nevertheless, it is a fascinating, almost unreal world, its impressive scars testifying of our solar system's violent history. Other "hot spots" include Titania, Uranus' largest moon, or Ariel, two worlds who appear to have consisted of ice, but have frozen from the outside to the inside, causing cracks and canyons to appear.
Uranus is a smaller brother, compared to its "neighbours" (a relative term in space) Saturnus and Jupiter, but still a lot bigger than the Earth is, about four times, making it the third largest planet in our solar system.
Mythologically / Symbolically
Uranus was the first ruler of the Gods and People, being married to the earth goddess Gaia; he himself was the god of the Skies. His reign came to a violent end when he was emasculated and mutilated by his own son Saturnus, who would then assume the highest rulership, only to be overthrown by Jupiter, fulfilling Uranus' curse when Saturnus slew him.
Despite the fact that most of his symbolical values and tasks have later been absorbed by Jupiter, Uranus' value as a symbol is of a more lasting meaning, and can be interpreted in a more categorical sense than Jupiter. Uranus was the first god to bring the chaos to an end, by opposing it to his own tightly structured, patriarchical order, and his bond with Gaia. He was also a father to the Titans and the Giants, creatures of tremendous power, but bondless anarchy, and perished in the revolt against Iuppiter.
At the outskirts of our solar system is a world which can also be referred to as the "blue planet", since it appears to radiate a peaceful blue colour. However, this peaceful exterior is only a faint cover for the truth below the upper atmospheric layers. In reality, this planet has by far the most violent storms, surpassing even those of Jupiter. Winds can reach velocities up to three thousand kilometres an hour, which is about three times the speed of sound.
A closer look at the planet also teaches us that it has bands of white clouds and dark spots, in a similar fashion to Jupiter's red spots. It is unknown whether or not they are as lasting as Jupiter's, as Neptunus has only been discovered in 1846, but it appears that they are more of a temporal nature, since its spots have been known to disappear from time to time. The planet was discovered through perturbances in Uranus' orbit, that scientists believed to be caused by another body. Thus, the existence of Neptunus was mathematically predicted, and so it was found.
Neptunus is about four times as large as the Earth, and the smallest of the four Jovian planets. Like them, it is also a gas planet, mainly being composed of various ices and hydrogen. It has a pretty regular orbit, and is in possession of a small ring, as discovered by the spacecraft Voyager 2, the only man-made object that has ever paid a visit to Neptunus' kingdom.
The planet has eight moons, the largest of them being Triton. Since this moon is significantly bigger than most other moons in the solar system (and by far the biggest in that region), the most commonly accepted theory is that it was captured by Neptunus, which would also explain its retrograde orbit. Because of this, in a distant time, the moon will either shatter or crash into its mother planet, due to a constant (but slight) loss of altitude caused by the tidal energies in its orbit. Its most amazing feature, however, is that of ice geysers. Astronomers had never expected to find a geologically active world so far from the Sun, but it appears they were wrong. It's unknown what exactly causes these ice geysers.
Mythologically / Symbolically
In ancient times, Neptunus was Iuppiter's brother, and ruler of the oceans. He shared his brother's appetite for women, and had a long line of various oceanic gods, spirits and demi-gods. He was also thought responsible for earthquakes, but remains best known as the God who sent the sea snakes to kill the Trojan priest Laokoon, who had warned his fellow citizens not to accept the Greeks' wooden horse, and his children; or the God who, feeling insulted by the Greek hero Odysseus, sent him adrift across the Mediterranean for about ten years. In general, he was considered one of the most powerful Gods.
As Neptunus is associated with water, he is often associated with an introvert sort of intuition, the subconscious, or intellectual insights and spiritual success, as opposed to Saturnus, who stands for material success..
When scientists discovered perturbations in Uranus' orbit, they calculated the source of this perturbation and found Neptunus. However, the degree of deviation in Uranus' orbit was too wide to be caused by an object of Neptunus' size, plus, Neptunus' own orbit appeared to be disturbed. So, the frantic search began for the ninth planet. It was eventually found in 1930. However, it was disappointingly small, and even today, there is still discussion on whether to consider Pluto a planet or simply an eccentric ice dwarf. Ice dwarves, as they have been discovered later, are much like the asteroid fields, small objects loosely gathered in a belt around the Sun called the Kuiper Belt. Unlike the planetoids, however, they are worlds that mainly consist of ice, and have been preserved since the very beginning of the solar system. The existence of this belt – also referred to as the Oört Cloud – has led to a few fantastic theories, none of them proven up to date.
If we turn our attention back to Pluto, we see a small world, smaller than our own Luna; a dark world, darker than the planetoids; unimpressive in about everything except its sheer darkness and its wide eccentricity. Its orbit is so eccentric that from time to time, it crosses that of Neptunus, making Neptunus the furthermost planet and Pluto the eigth. They will, however, never collide. Partially due to its orbit, a Plutonian year lasts about 248 Terran years, and the Sun is only visible as a very bright but distant star. The planet has seasons, but unlike Terra and Mars, which have seasons because of their axis, Pluto owes this – again – to its orbit. Its thin atmosphere, which probably consists mainly of nitrogen, freezes and condenses in the winter, much like Neptunus' moon Triton.
Pluto's most remarkable feature, however, which has until now given it the advantage of doubt by which we call it a planet, is its possession of a moon. This moon, discovered in 1977 and givent the fitting name of Charon, is about half the diameter and mass of Pluto. Some scientists even speak of the two bodies as a "double planet", and refer to Terra and Luna as a similar example. Little is exactly known about either world, as they are very far away for telescopic observation, and no spacecraft has visited them as of yet. Most astronomers and planetologists expect it to be quite similar to Triton.
Mythologically / Symbolically
Pluto was, in ancient times, the God of the Underworld, and a brother of both Iuppiter and Neptunus. Although the Underworld nowadays has a dark connotation, initially this chthonic God was revered as a fertility God. In Greek, the word "Ploutoon" means "the rich one". When we come to think of it, this association is not as absurd as it seems, since everything they knew grew from the inside of the Earth. Therefore, there may have been some comfort in returning to the catacombs of the world when one died. The myth of Pluto kidnapping Demeter's daughter Persephone explicitly refers to the seasonal changes, but in here Pluto is given the role of villain.
Other than ruling the dead, Pluto was also the Underworld's main judge. He comes across as stern, cold and distant. Associated with him are the darker places of our subconscious, such as fear and death (without being a personification of death, though, as this role was for another God); unknown riches, and a profound moral judgement.
… ubi nemo ibat antequam ("to boldly go, where no one has gone before")
There is still much to learn. Other solar systems have been discovered with other stars, but what do these planets look like? The more we examine the cosmos, the smaller and more humble we feel; but we can also feel lucky, simply for being alive in this corner of the galaxy.
Riddles that remain unsolved: what does cause the perturbations in the outer planets' orbits? Is there life in our solar system outside the Earth? Is there life outside our solar system, and if so, could it be intelligent? Will man ever set foot on other planets?
Certain is that Urania will always hold secrets for us, and give us inspiration.
All images ©NASA except Venus, ©Calvin J. Hamilton