Greetings, and welcome back to Journeys! This month I bring you my message on the discovery of the planet Neptune.
For Neptune in Pisces
This is part of a series of articles I am writing on the discovery of the modern planets, previous articles in the series can be found here, here, here and here, and other articles on Neptune can be found here and here. Due to the extreme length and detail I need to go into (my last post on the discovery of the planet Uranus was over 18,000 words long, twice as long as the average for this journal) I decided to split this message into two parts so that I can supply more imagery and do not have to cut anything from it to make it more digestible. This first part of the message provides a general introduction to the topic of Neptune in astrology, an account of the historical events which led to its discovery and the people involved, its naming and mythology, and the physical properties of the planet itself which we have so far uncovered, including its moons and ring system. Next month I will provide you with the second part of this message which delineates the discovery chart for the planet, discusses the history of the development of its significations by astrologers, and dives deeply into its oceans. Discussion about the astrological function of Neptune will be floating within both parts like a mist.
In my previous article in this series on the discovery of the planet Uranus I began by writing about the overwhelming changes which we are facing as a species, many of which are driven by science and technology, as well as by the population explosion. We are moving into an era where individuals are to be interconnected as never before, and in ways we have not even imagined until recently. The harnessing of electricity alone was a revolutionary game changer for our world, but now we have the microchip and we are moving into the era of the quantum sciences. Only 50 years ago we were mostly dreaming about flying cars, rocket men, laser guns and robots. Maybe some little green men and women, and a watch with a TV in it. None of what we are currently thinking about was on the radar of anyone except the most unhinged and adventurous (i.e. prophetic) theorists, science-fiction writers and fantasists. Yet here we are, faced with the imminent arrival of countless possible futures opened up by trans-humanism, quantum reality, exopolitics and exosocioliogy (the preparatory studies of how contact with extraterrestrial intelligence would affect human politics and society), interstellar travel through warp drive and wormholes and godlike status as the creators of virtual universes we can invite others into (or imprison them in). Elon Musk is talking to us about putting neurotransmitters in our brains, settling on Mars by nuking the polar ice caps from orbit and terraforming it, in effect making us the little green men and women. As we look into the future from where we are now if our vision is clear we can see a profusion of possibilities all of which are equally bizarre and surreal compared to what we know now, and so it seems as if at least on the surface of things the only thing that we can say for sure about our future is that we will not recognise ourselves. We are going where no one has gone before in ways they haven’t even imagined before.
These many visions of where we could be going are pouring into our world through the portal we opened when we discovered Neptune. When we discovered the planet Uranus, science and technology switched gears and everything began to accelerate towards where we are today and at an increasingly rapid pace. This will continue to be so, getting faster and faster and faster, leaving more and more of us behind unless we help each other out, until finally everyone is left behind when the technology curve overtakes humanity itself and we are in a new paradigm of existence, one radically remote from where we have been. In other words, the technological curve is racing towards a point where it will outstrip the human capacity to keep up. This is a dangerous point for us because at this point we need to have a vision that holds us all together, otherwise we are likely to lose control of our own progress and it will begin to devour us spiritually and socially, perhaps even replacing humanity as we know it physically. The point I am making here is that the gifts of science and literally magical technology which break the world are inevitably followed by a multiplication of potential future paths that humanity can take with its breakthroughs, as what was miraculous quickly becomes commonplace and thus expands the mind and the imagination to encompass deeper and formerly inaccessible regions of possibility.
Every technological innovation and every scientific breakthrough in the modern age leads to a new future for everyone. Our knowledge is becoming a collective database and yet our infrastructure still reflects millennia living with knowledge as a personal database – a thing which is possessed by individuals and collected by libraries, but was by no means pulled together onto a vast network potentially accessible and alterable by every single person on the planet. Since global infrastructure is still operating under the outdated paradigm it cannot deliver on the promise of collective knowledge. What good is it to be a doctor and to know instantly all the latest research in your field if the hospital you work for doesn’t yet have the equipment or the resources to use that information, and could probably never afford it either? Your patients will suffer or die just the same as they always did, but in addition you will suffer too because you will always know that you could have saved them. Gradually, or maybe not so gradually, this will change. Technologies like 3-D printing will eventually become so sophisticated that they will inevitably break the infrastructure that operates on the old paradigms of personal knowledge. When enough of this occurs we will reach the point I have talked about, the point at which we need to have a cohesive vision for ourselves in order to retain control of our own destiny, a vision of what the new paradigm should be.
Enter Neptune, the Dream Lord, Bringer of Visions and Keeper of the Waters. For just as following on from technological innovation and scientific breakthrough come new visions and new possibilities for the future, new dreams, so too was the discovery of the planet Uranus followed by the discovery of the planet Neptune.
The Ghost Planet
Given the astrological nature of Neptune you could not have made up a more appropriate discovery tale than what actually happened. Whereas the discovery of the planet Uranus was characteristically sudden, unexpected and surprising (is it a star?, is it a comet?, no, its Uranus!), the sequence of events surrounding the discovery of Neptune were very different. The story is one of sensing the invisible but continuously being eluded by it, seeking for a mysterious thing you know must be there but being hoodwinked either by your quarry, your unreliability, or confusions. Neptune, the planet of prophecy and divination, was literally discovered via prediction.
When William Herschel discovered the planet Uranus it was the first time that anyone in human history had discovered a world. Before that time the concept was not even part of the consensual human experience and so was largely considered fanciful and even imaginary. Yet it happened, and this moment was a watershed in the history of human awareness. After the discovery of this planet, others began to look more seriously into the deeps for signs of further unknown bodies. This is not to say that individuals before this time did not wonder about the possibility of there being other planets in our solar system but since nobody had actually demonstrated that they were there the whole concept was imaginary. Only the most visionary of minds would entertain the notion. One such mind was Galileo.
We now know that Galileo actually observed Neptune on December 28th 1612 and January 27th 1613, almost 170 years before Herschel’s discovery and over 230 years before Neptune was discovered by collective humanity. Using a self made spyglass with a magnification of 20x he was studying the moons of Jupiter when he noticed an unknown object which he probably took to be a new star. He recorded this and then about a month later seems to have realised that it had moved, with his journals indicating that he then went back over his notes and drawings to observe this movement. We know now that this was in fact Neptune because Neptune was in a close conjunction with Jupiter at the time (at 26° Virgo) and the positions he plotted for his wandering star match the actual orbital position of Neptune for that period. However, Galileo seems to have felt either uncertain or nervous about this discovery (we must not forget that he was eventually jailed for heresy by the Inquisition over heliocentrism and died under house arrest), or perhaps his restless mind forgot about it, because he kept it to himself. He was in the habit of sending short scrambled messages to his colleagues to establish his own claims to various discoveries like the rings of Saturn and the phases of Venus, but no such correspondence was sent in relation to his observations of Neptune. It’s possible, even probable given the nature of Neptune’s energy, that he actually did so but they were never unscrambled and that we have lost those messages entirely or they will show up mysteriously at some point. We also need to remember my earlier point here, that at this time the discovery of a new world was an imaginary thing, it was a far out concept. Perhaps the strength of Jupiter in Virgo was not quite enough to expand our paradigm, or perhaps this was really about seeding something in the human collective awareness through Galileo, something that would only bear fruit later. The reality today is that we don’t know what he made of it but we can easily hypothesize that in the winter of 1612-13, he suspected that it was a planet. For whatever reason, Neptune slipped through his net and swam away into the ocean for another 233 years.
We know of at least two other occasions on which Neptune was almost captured but dematerialised. On May 8th and 10th 1795 in Paris a star was noted in the position of Neptune but the uncertainty of its position was denoted with a colon, which was also used to indicate errors in observation, and so Neptune escaped. Then, the son of William Herschel, John, almost followed in his fathers footsteps on July 14th 1830, but he mistook Neptune for a star even though he could see it as a small blue disc. Neptune evaded us again.
In 1821, forty years after Herschel announced his discovery to the world, no further new planets had been discovered despite improvements in telescopes and far greater interest in the possibility, but great advances had been made by astronomers in observing the movements and behaviour of the new planet Uranus. A French astronomer named Alexis Bouvard had been working out some of these details and published them. In these tables he showed that the new planet was not behaving as expected and he theorized that the cause was the gravitational effect of an undiscovered planet, but he was unable to prove this. However, his calculations opened the door for the eventual discovery of Neptune two decades later. At this time in history Neptune was actually conjunct Uranus (in Capricorn, just as it was in the early 1990s when this conjunction recurred), and so the ghost planet was literally setting itself up to come on stage.
When Uranus had moved 90° away from that conjunction with Neptune, 22 years later in 1843, the trail is picked up by a 24 year old Cambridge graduate (and later professor) named John Couch Adams, who had learned about Bouvard’s work while an undergraduate and had become convinced that a mysterious undiscovered planet was responsible. He believed that in the face of everything that had been attempted before that he could calculate the mass, position and orbit of this new planet using the observed data on Uranus and applications of Newton’s laws of gravitation. And it’s here that the real controversies start because the trail is also being picked up in continental Europe by 32 year old French astronomer Urbain Le Verrier. Unbeknown to one another the two scientists/mathematicians begin working on the same mystery. It’s important to note that at this time in history relations between the French and the British were not exactly cordial, and scientific discovery was fiercely competitive, and so what was brewing in this cauldron was controversy and trouble.
This invisible cat seems to have come out of the bag through the involvement of the current Astronomer Royal, Sir George Airy, who was 45. Adams took his work on the ghost planet to James Challis, director of Cambridge Observatory, in September 1845, requesting more data from the Astronomer Royal, which he received. He then attempted to meet with Sir George Airy twice in October, but he called on Greenwich Observatory unannounced, while Airy was busy dealing with both incest–murder charges against a senior worker and the impending birth of his seventh child. Adams leaves his manuscript with Airy, but does not supply all the calculations. Airy writes back to him requesting them, but they never arrive. Adams is too disorganized, nervous, procrastinating or forgetful. Airy is a mathematician, he needs the crunch before he feels convinced, so he lets it slide. However, when Le Verrier published his first prediction on the position of the new planet on June 1st 1846 it came almost immediately to the attention of Sir George who recognised its similarity to the calculations that Adams had made, and realizing the urgency he immediately acted by forming a secret group including Challis and Adams. He had considered Adam’s work little more than a curiosity up until this point, but now he realised the race was on for a huge prize. Challis was instructed to scan the heavens and Adams supplied some directions.
And so it was that the summer of 1846 became a race to capture Neptune. Challis was sent searching the wrong parts of the sky by some of Adam’s calculations, but even so Challis himself observed Neptune on two occasions (August 8th and August 12th). However because he lacked an up-to-date star map he was unable to identify it as the new planet, and so he missed it. Le Verrier on the other hand was completely oblivious to the secret group competing with him in the discovery market and had been unable to gather any interest from influential astronomers. So on September 18th he sent his findings to the Berlin Observatory in Germany and asked them to look for the new planet. Five days later this letter was received by Johann Gottfried Galle, a 34-year-old astronomer. After talking to a student at the university who suggested comparing an existing image of the area of the sky with current observations, Galle became the first human being to lay eyes on Neptune and know definitively what he was looking at. It was just 1° away from where Le Verrier had predicted it would be and about 12° away from Adams prediction. The date was September 24th, 1846. Galle always maintained that the credit for the discovery should be Le Verrier’s, but history records Galle in most entries. He wrote back to Le Verrier saying:
“the planet whose place you have computed really exists.” (emphasis in original)
This one sentence is a fitting end to the search for the phantom planet, but is not the end to the story. In hindsight, it might seem clear but at the time this entire sequence of events was extremely controversial and mysterious and ignited fierce rivalries between France and England. Argument raged over who should have attribution for discovery, Adams or Le Verrier, with the storm eventually settling down to agree on a joint attribution. However, the spirit of this controversy returned to haunt us again in 1998 with the recovery of documents stolen from the Royal Observatory in Greenwich (seemingly by a respected astronomer). These documents, referred to as “the Neptune papers”, which had been missing for decades, strongly imply that John Couch Adams was essentially “spun” by British astronomers (i.e., Airy) in a positive way, in other words that his calculations were fuzzier than what was actually reported.
Le Verrier was soon showered with honours as the world and especially Europe was set ablaze with wonder and expressions of admiration, he was blessed with rewards and praise and was almost euphoric upon learning that he was definitely not crazy or imagining things, having everything that he had worked for confirmed.
There was talk of how marvelous it was that the human brain could outperform a telescope. It was ecstatic to be at the centre of. However, his mood was soon overturned by the naming crisis which almost immediately emerged. At a certain point, when he was asked to provide his opinion on what this new planet should be called, he was acting weirdly from an emotional dilemma due to the fierce rivalries among astronomers on both sides of the waters. In an invisible way he had tied his fate to that of the world he tracked down, and in this respect it’s fascinating to note that the word in French for transparent glass (anything invisible is Neptunian) is ‘verre’.
The ‘planet exterior to Uranus’, as it was initially referred to, soon gained a plethora of potential names. After setting eyes on the new world, Galle immediately proposed the name Janus “…the most ancient deity of the Romans, whose double face signifies its position at the frontier of the solar system”.
When Le Verrier received the confirmation letter from Berlin on September 28th it arrived just a bit too late to be announced at the Academy of Science meeting on that day and so instead he gave the story to French newspapers who published it on September 30th, 1846. In this publication he proposed the name Neptune. With the publication of these papers the news reached the front page of ‘The Times’ in England the next day. When that issue landed on Airys desk, he went pale. The French had beaten him!
Cue all hell, breaking loose.
Le Verrier wrote back to Galle in Berlin on that day, October 1st, expressing his dislike for the name Janus on the grounds that it implied that Neptune (the name he proposed in this letter) was the last planet in the solar system to be discovered, which he saw no grounds for. An interesting Neptunian thing happens when this letter arrives as a visiting astronomer (Sir Henry Holland) is discussing with Galle and the Director of the Berlin Observatory the topic of naming the planet. ‘Vulcan’ was suggested by the Director and Galle replied that he was expecting a letter from Le Verrier to arrive soon with his suggestions, which the group agreed they would defer to. Less than an hour later there was a knock at the door and the letter arrived proposing Neptune. The director then declared that the name must then be Neptune. Holland later wrote of this moment:
“It was a midnight scene not easily to be forgotten. A royal baptism, with its long array of titles, would ill compare with this simple naming of the remote and solitary planet thus wonderfully discovered. There is no place, indeed, where the grandeur and wild ambitions of the world are so thoroughly rebuked, and dwarfed into littleness, as in the Astronomical Observatory”.
Note that the post arrives at midnight! This might be the norm for night sky watchers, or it might have been unusual, I don’t know.
Le Verrier also wrote three letters to important observatories in Europe on October 1st in which he proposed again the name Neptune but also in addition the symbol of a trident for its use. Yet in these letters it seems that instead of simply expressing his wishes directly by saying “I want it to be called Neptune and for its symbol to be a trident”, he chose to give the impression that these things had already been approved by the French Bureau des Longitudes, when in fact it had had no opportunity to meet. This caused a lot of trouble for him later when amidst the mayhem to come the Bureau had to refute these claims and threaten him with legal action.
At this point French astronomers (led by their most eminent personage, Francois Arago) began insisting on naming the planet after Le Verrier himself, to the extent where they declared they will use no other name, regardless of what others decide. The name ‘Herschel’ began to replace others in the French almanacs and in reference to the planet Uranus as part of this effort. Some suspect that this was a devious scheme by Le Verrier himself, but I doubt this. However, it does fit the theme of Neptune whether or not it happens to be true – suspicions of fraud and deception are just as much a thing of Neptune as actual fraud and deception.
Across the channel in England Sir George Airy proposes the name Oceanus, claiming that Neptune “disturbs my mythological ideas”, but the reception of the French to the British claim is caustic. The situation starts to get really toxic as the old national rivalries ignite. Britain and France both claim the right to name the world, implying their precedence of discovery. We have to remember that this is the beginning of the Victorian era and that Sir George Airy as Astronomer Royal is a very widely respected figure in European astronomy. This is the point at which Le Verrier shrinks back from proposing anything all, lapsing into silence on the matter and becoming confused, nervous or evasive when asked about it. However, privately he makes references to the pretensions of the British and that he is sickened by the whole affair. He had seen an English man trying to steal his glory, French astronomers insisting on naming it after him and then astronomers elsewhere in Europe pushing back against that. He was, in modern parlance, totally pissed off with the whole situation and withdrew from keeping up with developments. He was no longer part of the work at the observatory and did not engage in his usual socialization. He was the greatest astronomer in France, probably the greatest astronomer France has ever known, but glory had turned incredibly sour. He refers to his discovery at this point as “the unfortunate planet” and in correspondence he is making a final effort to have it named after himself in defiance of the British (doing so by proclaiming that he is adopting ‘Herschel’ for Uranus). At this point I get the feeling that he himself is not only tired, disenchanted and disillusioned with the whole process but also confused about how to resolve it.
Things churn on without him of course, with arguments that Adams was the first theoretical discoverer and that British data on Uranus had been used, or that Galle had been first to knowingly see it and so it should be a German and not a Frenchman who names it. The result was that a confusing smog of names were conjured and in use by the end of 1847, including Hyperion, Minerva and even Demogorgon. The situation at this point was also the same concerning the naming of the planet Uranus. While all this mayhem is going on, however, Sir George Airy writes a letter to Le Verrier on February 28th 1847 that ultimately breaks the deadlock by saying he will adopt Neptune so this gives us a day upon which we can say the issue was effectively settled (as much as any issue of Neptune is effectively settled, since Le Verrier apparently made no reply). This name then emerged as a default position (especially as Friedrich von Struve, a prominent German/Russian astronomer, came out in favour of it on December 29th 1846, which may have prompted Airy to do the same). Nobody especially liked this but Neptune had emerged as the name through being the least partisan, with co-discovery through an Anglo-French effort being the cause. Once this situation settled in, further degrees of consensus emerged among astronomers. They agreed that comets would be named after their discoverers but that new planets would be named after mythological beings and gods. The names attributed to the planet Uranus were gradually changed to the name we use today. Thus the confusion and controversy surrounding the naming of Neptune led to the abandonment of egoistic and nationalistic based attempts to gain a token immortality in the heavens and the adoption of naming new worlds after deities and other mythic beings, confusion settled into a new convention, and poor Le Verrier became the sacrifice. Herschel may have been the first person to discover a new world, but Le Verrier was the first to predict one into reality.
The adoption of the name Neptune immediately connected this world with all mythologies relating to the ocean and all deities of the sea, and different cultures followed suit with their languages. Greeks named it Poseidon, Maoris named it Tangaroa, the Chinese, Vietnamese, Japanese and Korean people translated it as “Sea King Star”, and so on. However what is less well known about Neptune and a large number of the deities connected to the ocean and the sea throughout the world is that the deity is not only connected with ocean life but also springs, rivers, streams, fountains and other bodies of water inland, and that this connection to inland water may actually even be older than the connection to oceans in some cases, for example in Greek myth Poseidon may originally have been the deity of springs. Furthermore, this deity is also often connected with earthquakes, chariots, and horses. In fact he is also originally thought to have been a god of horses before he was a god of the sea. This connection is obvious in much of the statuary of Poseidon and Neptune which depicts him being drawn by seahorses or water spirits in the shape of horses (sometimes dolphins, who were sacred to him) while he stands with a billowing cloak upon a giant conch shell like the coolest surfer ever. The connection to earthquakes may seem a little mysterious until you think about the effect of earthquakes under the ocean and how destructive and godlike a force of nature these can be, especially to people in the ancient world. The horses are actually spirit beings called hippocamps, and you see them pop up time and time again in the mythologies of the world that are connected to spirits of the oceans and the seas, as well as rivers. They embody the energy of the ocean, the currents and the movement of the waves. It seems that the connection of this deity to horses began its decline in the time of the Romans, who were very keen on inventing gods for everything and so invented or formed their own god of horses. The connection to horses and chariots is mythically traced back to the tale of him working with Minerva (Athena in Greek) to create them. Athens was a major city for Poseidon/Neptune, and the two deities seem to have had some kind of dispute over who would claim the city, with Athena emerging the winner even though Poseidon gifted the King of Athens with the original horse, probably formed from a Hippocamp. The god of the oceans has one of his many tantrums when he is refused the prize and afflicts Athens with a drought.
It’s worth dwelling on these violent and often petulant temper tantrums for a little bit, as they are very at odds with our picture of astrological Neptune. The dark side of this god is actually very dark indeed, giving us a strong warning about the destructive power of this seemingly placid, passive planet. Time and again in the Greek and Roman traditions he behaves abominably, showing us that even the gods are not above petty human frailties and dark desires and drives. In some cases he comes across as impossible to please, capricious and merciless, even evil. Perhaps the most powerful example of this is the tale of his rape of Medusa, the famed Gorgon. Before she became a monster she was a beautiful priestess of Athena. Her hair was so beautiful that people whispered that it was even more beautiful than the hair of the goddess herself. Vain and insecure Athena grows jealous. Meanwhile, Poseidon is growing lustful and one day he just decides to have his way with the beautiful mortal girl. She runs into the temple of Athena for protection, but the goddess ignores her and Poseidon rapes her. Now, you get different versions of the story at this point with some saying that Medusa was so horrified that her hair transformed into snakes, and another saying that a disgusted and enraged Athena appeared to her afterward and being unable to punish Poseidon (a likely excuse) chose to heap all the punishment onto Medusa, cursing her. Following this, her serpentine head is chopped off by Perseus who has been gifted everything he needs to do that job by the gods themselves, including Athena, and at this point Medusas headless corpse gives birth to the twin offspring of Poseidon which issues from her blood as a winged horse, Pegasus, and Chrysaor, a giant wielding a golden sword. Then, even in death, she acts as a force for good, allowing Perseus to defeat the sea monster Cetus and rescue Andromeda. Medusa is one of the most misunderstood, most unfairly maligned and wrongly perceived figures in all of mythology, and she has her unwanted and uninvited contact with the god of oceans to thank for that. He distorts things as if seen under water, water that is today often very murky.
In noting some of the darker elements of Poseidon/Neptune I would like to mention that as an astrologer our use of mythology to delineate the nature of the planets seems to work best when we focus not on the actual stories and tales connected to the deity, but on their character. The tales are often culturally embedded and therefore require cultural decryption by outsiders, but the character of these beings is often much more universal. The stories attached to gods of the sea may differ, but we see time and again the same imagery, associations and character traits in their behaviour, no matter the culture. Neptune, along with his other expressions in mythology, is often unforgiving, vindictive and vengeful (Tangaroa remains angry at the gods of the land even today for harboring the reptile children who left him, for example), pointing to the potential emotional turbulence of this world. He is also often lustful and exceptionally potent and fertile, siring countless children with everything that he can, not just humans but nymphs and animals as well. Randy isn’t the word, the guy has a serious sex addiction problem and is depicted as a serial rapist by the Greeks. He often takes the form of running water or an animal for these sordid seductions, and I’m not aware of any stories about him seducing men, although I know they were told at one point. However the position of these oceanic deities is also often primordial, they are fertile as gods which means they are involved in the creation and/or domains of the universe as we know it. Poseidon for example draws lots with his brothers Zeus (Jupiter) and Hades (Pluto) after the war against the Titans (during which the Cyclops crafted Poseidon’s magical trident for him), with Zeus gaining the sky, Hades the land and the underworld and Poseidon the seas and waters. Repeatedly in studying the myths of gods of the sea they are also described as gods of the cosmic or primordial sea, progenitors of life, and I think it is these ideas that the later Greeks are turning into misogynistic sexual scandals, probably for entertainment purposes.
For obvious reasons these deities are primarily worshiped by seafaring people and islanders, which is maybe one big reason why there are so few temples to Neptune or Poseidon mentioned in history. Perhaps they are under the waves now. In most cases offerings have to be made to the ocean deity before fishing or setting out in boats, in recognition of the fact that in leaving the land one is departing one realm for another and must show its host the proper respects. These people know all too well the fury of the sea and often perform rituals to keep it calm. In Rome Neptune had but one temple – near the racetrack – which we know already existed in 206 BC but was actually built on the site of a much older altar about which we know nothing. The main festival called Neptunalia took place on July 23rd at the height of the summer and was devoted to the practice of conserving and draining water. The rituals often took place in the forest under huts made from branches, the participants drinking spring water and wine in the shade. In keeping with the spirit of Neptune, it was a libidinous time freeing people to behave merrily without the usual social constraints.
Before leaving this section I would like to point readers to “The Gods of Change” (1989) by Howard Sasportas, in which he makes a compelling case equating the principle of Neptune with the mythology of Orpheus. If you’re looking for a story from classical mythology that expresses astrological Neptune, it seems to me that the story of Orpheus resonates much more powerfully with it than the mythology connected to the deity. There is for example the fact that Orpheus is a musician who is able to drive people mad, into ecstasy or despair through the power of his playing, the fatal doubt and distrust, nervousness or suspicion that causes him to look behind at the last moment and lose his dream lover, and the surreal tragedy of his death at the hands of people living in denial of tragedy, which then ironically reunites him with that lover.
The Physical Planet
There is a reason why Neptune was so elusive for so long, that being the massive distance at which it orbits the Sun. Twice as far flung as the planet Uranus is, Neptune is completely invisible to the naked eye and only occasionally visible as a blue dot through even modern portable telescopes. Add to this the meteorological problems of cloud cover and the planet has a very effective cloaking device. Measured in miles the distance to Neptune is about 2.8 billion miles, or 4.5 billion km, 30 times as far away from the Sun as we are. This is a very dark and cold region of space and beyond this point very little is known as we are only just beginning to explore it. This vast distance has kept things hidden from us even until recently, with most of the moons of Neptune only being discovered in the late 80s and the early part of this century. For a very long time, there were only theories and imagination about what this world was really like, and most of what we know today comes from the Voyager 2 mission which also gave us our data and images of the planet Uranus. Voyager 2 reached Neptune on August 25th 1989, – exactly thirty years ago from the time of writing – and we haven’t been back since, despite a number of plans being drawn up. Telescopes like Hubble continue to give us more information until we can go back, but there are no public plans in motion to do so at the moment.
Both visually and materially Neptune is very similar to Uranus, being an azure blue colour that is slightly deeper in hue and slightly larger in size. Neptune also appears with rings, moons, fierce winds, a weirdly off-centred magnetosphere and some anomalies which are similar to those we have observed on Uranus. It is also an ‘ice giant’, a subclass of gas giants that are thought to arise from icy components rather than gaseous ones when the solar system was being formed. At first glance, one could argue that Uranus and Neptune are twins. However, Neptune has more meteorological activity, having displayed both a Great Dark Spot and a Small Dark Spot, whirlpools in the cloud layer, the former of which we observed to have disappeared and be replaced only five years after it was first sighted, and there are other notable differences between the two.
It is extremely large compared to our planet, being 17 times the mass of Earth, but it rotates on its axis at a very similar angle to ours. This means that it experiences seasons much like our planet does, namely it has a spring, summer, autumn and winter with an equal amount of time allotted for each, however because the orbit of Neptune is so far away each of these seasons lasts about 40 Earth years (while its day is only 16 of our hours, an hour less than a day on Uranus). A single year on Neptune (one orbit of the Sun) is about 165 years on Earth.
Of course, seasons on Neptune are nothing like seasons on planet Earth. This is the stormiest planet in the solar system. The winds on Neptune reach the highest recorded speed of any wind ever observed, a near supersonic 600 metres per second (three times as fast as the fastest wind speed recorded for the planet Uranus). This equals a speed of about 1300 mph, fast enough to blow you into atoms. Part of the cause of this high speed is the fact that the poles of Neptune rotate at a different speed than the equatorial regions, because ice giants are mostly fluid, and so their mass rotates like a cyclone. Theoretical models also show that the high-pressure involved in this planets atmosphere causes methane to decompose and be crushed into diamond crystals which rain down from the sky and collect in the mantle of the planet, as I explained in the previous article in this series (this is also thought to occur on Jupiter and Saturn). This means that human beings cannot survive a landing on Neptune. There is first of all nothing to land upon except the core of the planet where unbelievable pressures and temperatures make life impossible for us, just as it would be if we had to live on the core of planet Earth but with far greater forces involved. We don’t know of course what the core of Neptune is made of but it is thought to be composed of iron, nickel and various silicates. I think it will prove to be more exotic than that.
The same I think will also prove true of the mantle and the atmosphere of this planet. While Neptune’s atmosphere is ultra cold the mantle of Neptune is a hot fluid substance like the mantle of the Earth, and is thought to be composed of methane and ammonia as well as water, and is highly conductive. Oxygen is thought to crystallise inside this mantle deeper down. At the top of the atmosphere of Neptune the composition is mostly hydrogen and helium, but trace amounts of methane are present which act to filter out the red light the planet receives, giving it its sapphire blue colouring. However it is thought that there may be some other agent at work deepening the colour, something other than the darkness of space. Like Uranus, despite being extremely far-flung from the local source of heat Neptune is mysteriously hot, even more so than Uranus is. It receives less than half of the energy from the Sun than Uranus does but is equivalent in surface temperature, somehow emitting more than 2.5 times more than the amount of energy it receives, energy which drives those hellish winds. In 2007 it was observed that there was a hotter area located at the south pole which allowed massive plumes of methane to fountain out into space. This is caused by the south pole facing directly into the Sun, so that when Neptune moves to the other side of the Sun the fountain will be emitted from the north pole instead.
Neptune’s most important accessory is its trident moon, Triton, but like its mythological namesake it seems to have created quite a little nest or family for itself. Currently we are aware of 14 moons, and there are definitely more which we do not know about currently. Most of these moons are very small, a few dozens of kilometres across in some cases, but Triton is significantly larger and spherical in shape, while the remaining moons are irregular in form. Astronomers currently group the moons of Neptune into two groups which they label as regular and irregular moons. Seven regular moons have inner circular orbits resting in Neptune’s equatorial plane, while seven irregular moons, with the exception of Triton, have egg shaped elliptical orbits far-flung from Neptune and are often in retrograde orbits, which means they rotate around Neptune in the opposite direction to the direction that Neptune itself is rotating on its axis. The main distinction is that the regular moons are closer and are thought to have formed within Neptune’s orbit while the irregular moons are farther away and are thought to have been captured by Neptune at some point and been drawn in towards its orbit from the Kuiper belt. All the moons are named after water nymphs, sprites or deities in the same way that the moons of Uranus have been named after air spirits.
The first moon was discovered just 17 days after Neptune itself on October 10th, 1846 by English astronomer William Lassell. This was Triton, which is unsurprising because it makes up about 99% of the mass of Neptune’s moons, but the name Triton did not come into common usage until the 1930s. The other moons are so tiny and so far away that it was 103 years before the second one, Nereid, revealed itself (May 1st, 1949). Larissa, the third moon, was detected on May 24, 1989, just before Voyager 2 arrived in late August 1989 and added five more (Naiad, Thalassa, Despina, Galatea and Proteus). The remaining moons have only been discovered in the 21st century from the use of large ground-based telescopes. Halimede, Sao, Psamathe, Laomedeia and Neso were discovered on August 13/14th 2001, and a year later an additional potential moon or possibly a centaur was observed but then we lost track of it and so it remains undiscovered for now. The 14th and most recently discovered moon, Hippocamp, was discovered on July 1, 2013, only six years ago, and was given its name in February of this year.
Closest to Neptune, the inner (regular) moons in order of distance are Naiad, Thalassa, Despina, Galatea, Larissa, Hippocamp (labeled as S/2004 N1 in the images), and Proteus. Naiad, the closest moon of Neptune, takes about 8hrs to orbit Neptune. The first three of these moons orbit Neptune faster than it rotates and so are projected to eventually be pulled apart as they draw closer to it. Proteus is the largest of the inner moons at a diameter of 420 km (about 261 miles) and Hippocamp the smallest with a diameter of only about 35 km (about 22 miles). We know almost nothing about them, in fact we know almost nothing about any of the moons, with most of our data being on Triton. Current thinking on these moons is that they were formed after Neptune captured Triton from its former position as a dwarf planet in the Kuiper belt, causing massive disruptions when it entered the system. The Adams ring system of Neptune is probably composed of smaller debris from this event.
The irregular (outer) moons of Neptune in order of distance (closest to furthest) are Triton, Nereid, Halimede, Sao, Laomedeia, Psamanthe and Neso. Neso, the farthest moon of Neptune, takes about 26 years to complete an orbit. Triton and Nereid are the two largest irregular or outer moons of any planet in our solar system, with Triton having a diameter of about 2700 km (about 1700 miles) and Nereid a diameter of about 350 km (about 218 miles). They also both have quite remarkable orbits with Triton’s being perfectly circular and Nereid’s being extremely eccentric. Triton takes about 6 days to orbit. Projections show that Triton’s retrograde orbit and its proximity to Neptune will lead to its destruction in about 3.5 billion years. When Voyager 2 performed its flyby of Triton it observed geological activity in the form of 8km high nitrogen geysers at the polar cap, an indication that there may be a subterranean ocean looked deep within the moon’s core. Settling on Triton in any form would have to contend with some of the coldest temperatures recorded anywhere in the solar system (about -235C, at which point you have to deal with nitrogen and carbon monoxide freezing, which is extremely beautiful to look at but lethal). As is the case with our Moon, Triton’s rotation is tidally locked so that it always presents the same face towards Neptune. Water ice is present on the surface (as on Nereid too) and some kind of subterranean ocean could potentially harbor life as on Jupiter’s moon Europa. Triton takes about 6 days to orbit, meaning time contracts to a 6 day month on Neptune.
Neptune has five named rings which were first discovered on 22 July 1984 in Chile. This allowed them to be photographed by Voyager 2 years later. Naiad, Thalassa, Galatea and Despina have their orbits within the rings. One of these rings has five arcs which are proving to be surprisingly persistent and permanent, having existed since they were observed in the 1980s. There is no explanation for them. Three of these rings are narrow with a width of only about 100 km, while the remaining two a very broad with a width of thousands of kilometres. All five ring systems are reddish in colour and composed of large quantities of dust making them similar in composition to the rings of Jupiter and very dissimilar to the ring systems seen on Saturn and Uranus (which contain very little dust). The moons of Despina and Galatea (and probably others) act as shepherd moons for the ring system (moons which cause the rings to form and maintain their shape). These five rings have been named after astronomers who contributed to our knowledge of Neptune, and so Le Verrier gained a consolation prize, but he did not live to know about it. A very faint sixth ring has yet to receive a name. Some of Neptunes rings are only partial, and are the remnants of former moons.
Currently considered the last planet of the solar system after the re-categorisation of Pluto as a dwarf planet, Neptune may be forced to give up that position in the 21st century. In this decade astronomers have uncovered strong evidence that a super-Earth planet 2 to 15 times the mass of Earth may exist as far as 200 to 1500 times the distance from Earth to the Sun. They base this prediction on mathematical modeling much as astronomers did in the pursuit to discover Neptune. So far despite looking very intently for it they have been unable to locate it, but it may just be a matter of time before Neptune, the Lord of the Deeps, introduces us to a titan.
Next month, we go deeper, join me for a dive!