Thendara House is a science fantasy novel by American writer Marion Zimmer Bradley , part of her Darkover series and a sequel to The Shattered Chain . It was originally published by DAW Books (No. 544) in 1983 . The book was co-written by Jacqueline Lichtenberg , without credit.
144-619: The title refers to the Thendera Guildhouse of Renunciates , a religio-military sisterhood whose members live independently from Darkover's rigid patriarchal society. In terms of the Darkover timeline, the events of Thendera House take place three or four years after The Spell Sword and about two years after the events of The Forbidden Tower . Magda Lorne tenders her resignation from Terran service to her supervisor, Cholayna Ares, saying that she has taken an oath to spend six months in
288-471: A chieri gives one to his human lover so she can call on him if necessary. A matrix stone can be attuned to one person, who will always carry it with him and cannot lose it because he always knows where it is. If it is forcibly removed from him, he may go into shock and die. As related in The Bloody Sun , a small matrix stone can be attuned to a person and used as a lock on a box, and only the person to whom
432-469: A geodynamo that generates a magnetic field . Similar differentiation processes are believed to have occurred on some of the large moons and dwarf planets, though the process may not always have been completed: Ceres, Callisto, and Titan appear to be incompletely differentiated. The asteroid Vesta, though not a dwarf planet because it was battered by impacts out of roundness, has a differentiated interior similar to that of Venus, Earth, and Mars. All of
576-459: A nebula to create a young protostar orbited by a protoplanetary disk . Planets grow in this disk by the gradual accumulation of material driven by gravity , a process called accretion . The word planet comes from the Greek πλανήται ([[[wikt:πλανήτης|planḗtai]]] Error: {{Transliteration}}: transliteration text not Latin script ( help ) ) ' wanderers ' . In antiquity , this word referred to
720-406: A rogue planet , is believed to be orbited by a tiny protoplanetary disc , and the sub-brown dwarf OTS 44 was shown to be surrounded by a substantial protoplanetary disk of at least 10 Earth masses. The idea of planets has evolved over the history of astronomy, from the divine lights of antiquity to the earthly objects of the scientific age. The concept has expanded to include worlds not only in
864-426: A star , stellar remnant , or brown dwarf , and is not one itself. The Solar System has eight planets by the most restrictive definition of the term: the terrestrial planets Mercury , Venus , Earth , and Mars , and the giant planets Jupiter , Saturn , Uranus , and Neptune . The best available theory of planet formation is the nebular hypothesis , which posits that an interstellar cloud collapses out of
1008-516: A triaxial ellipsoid . The exoplanet Tau Boötis b and its parent star Tau Boötis appear to be mutually tidally locked. The defining dynamic characteristic of a planet, according to the IAU definition, is that it has cleared its neighborhood . A planet that has cleared its neighborhood has accumulated enough mass to gather up or sweep away all the planetesimals in its orbit. In effect, it orbits its star in isolation, as opposed to sharing its orbit with
1152-464: A "screen" by placing several jewels within glass in a pattern that they determine on an ad hoc basis, depending on the purpose of the screen. This can magnify telepathic powers even more. A screen cannot be managed by a single matrix user. The geological survey conducted The Bloody Sun is accomplished by making and using such a screen; in Sharra's Exile and Two To Conquer , a screen is used to teleport
1296-527: A Terran colony. Peter, ever ambitious, ignores her. Jaelle realizes that Peter does not consider her an equal partner in the marriage, and that in many respects, she has broken her Renunciate oath by marrying him. In the Guildhouse, Bryna gives birth to a boy; since no male may stay in the guildhouse, he is adopted out to a male relative. Camilla tells Magda the story of how she came to be a Renunciate. Keitha's abusive husband arrives with two mercenaries, demanding
1440-520: A Tower for training advances through degrees of competence: first Monitor, then levels of Mechanic. Each degree requires an oath to do no harm and not abuse laran . First, a trainee learns to set up "barriers" to keep his thoughts from being read against his will, and to keep from "broadcasting" his thoughts and feelings. The next stage of training involves learning how to read one's own physiological symptoms such as heartbeat, respiration and body temperature, and (with permission) to read those of others. Once
1584-494: A boundary, even though deuterium burning does not last very long and most brown dwarfs have long since finished burning their deuterium. This is not universally agreed upon: the exoplanets Encyclopaedia includes objects up to 60 M J , and the Exoplanet Data Explorer up to 24 M J . The smallest known exoplanet with an accurately known mass is PSR B1257+12A , one of the first exoplanets discovered, which
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#17328765676011728-582: A consciousness-raising session with her future sisters regarding her motives for joining the Renunciates. She experiences a vision of the Goddess Avarra. Jaelle meets with Kadarin, a Terran operative, to assist him in prepping for a trip to the Dry Towns. She is assigned to give Alessandro Li a lesson in Darkover's history, but comes to distrust his motives, telling her husband that he wants to reduce Darkover to
1872-505: A counterforce. Bradley noted that most of the fan fiction she received was inspired by the Renunciates, and that she had met individuals who had taken Renunciate-style names or were attempting to live in women's communes inspired by the Renunciate guildhouses. A Renunciate takes an oath, and thereafter is known only by her first name and the name of her mother, with the connecting word "n'ha", meaning "daughter of". The woman who administers
2016-679: A disk remnant left over from the supernova that produced the pulsar. The first confirmed discovery of an exoplanet orbiting an ordinary main-sequence star occurred on 6 October 1995, when Michel Mayor and Didier Queloz of the University of Geneva announced the detection of 51 Pegasi b , an exoplanet around 51 Pegasi . From then until the Kepler space telescope mission, most of the known exoplanets were gas giants comparable in mass to Jupiter or larger as they were more easily detected. The catalog of Kepler candidate planets consists mostly of planets
2160-508: A fan newsletter in 1978, saying, "The map in HH was fortunately inaccurate enough to be ignored". In any event, it does not match the Speakman map that illustrates this article. Thorsten Renk's attempt at mapping Darkover based on the descriptions of journeys provided in several of the books (starting with Darkover Landfall and ending with The Heritage of Hastur ) produced a third map that does not match
2304-762: A few years. This results in a Comyn adult having "foster-brothers" and "foster-sisters". One example of this is Regis Hastur and Lew Alton. Regis lived at Armida during part of his childhood. The Comyn families are: Commoners are the population of Darkover that are not members of a Comyn clan or family. In general, they are portrayed as less educated than the Comyn, hard-working, shrewd and honorable, although some are members of bandit gangs. Some of them are fairly wealthy, owning lands and raising crops or animals, or having successful businesses, such as tailoring and dressmaking, leatherworking and other crafts, milling and cheesemaking, or inn-keeping. They form their own councils and petition
2448-659: A focus and a way to magnify laran . Bradley's fictional world is populated with an intelligent species, the Chieri , already ancient and in decline when the human colonists arrive. As the series developed, she introduced three other sapient native species—the Trailmen, the Forge-Folk, and the Catmen—as well as two genetically engineered sapient species—the Cralmac and Kyrri. One additional species
2592-522: A genetic basis for the development of laran on Darkover, noting that the original population of the colony derived overwhelmingly from north-west Europe (the Scottish highlands, Ireland and the Basque country) where a belief in supernatural abilities such as the second sight is common, and red hair is common as well. A matrix jewel or "starstone" provides a focus and a way to magnify laran . In Darkover Landfall ,
2736-442: A list of omens and their relationships with various celestial phenomena including the motions of the planets. The inferior planets Venus and Mercury and the superior planets Mars , Jupiter , and Saturn were all identified by Babylonian astronomers . These would remain the only known planets until the invention of the telescope in early modern times. The ancient Greeks initially did not attach as much significance to
2880-411: A mass 5.5–10.4 times the mass of Earth, attracted attention upon its discovery for potentially being in the habitable zone, though later studies concluded that it is actually too close to its star to be habitable. Planets more massive than Jupiter are also known, extending seamlessly into the realm of brown dwarfs. Exoplanets have been found that are much closer to their parent star than any planet in
3024-471: A mechanic, notices that the hinge on a door is beginning to rust, and, taking out his matrix, he stops it. Greater skill is required to perform tasks such as refining metals or causing rain to fight a forest fire. Despite all the things that can be done with laran , it is not wise to use it for everything; in The Bloody Sun Rannirl, a Level 2 Mechanic, repairs a leaky roof at Arilinn by climbing onto
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#17328765676013168-479: A metallic or rocky core today, or a reaccumulation of the resulting debris. Every planet began its existence in an entirely fluid state; in early formation, the denser, heavier materials sank to the centre, leaving the lighter materials near the surface. Each therefore has a differentiated interior consisting of a dense planetary core surrounded by a mantle that either is or was a fluid . The terrestrial planets' mantles are sealed within hard crusts , but in
3312-477: A mining survey faster and better than the Terrans. In the introduction to Free Amazons of Darkover , Bradley wrote that her Renunciates have become "the most attractive and controversial of my creations". The Guild of Oath-Bound Renunciates, called Free Amazons and com'hi letzii in earlier books, are women who have opted out of Darkover's traditional gender-based roles , including marriage, obligations to clan, and
3456-519: A mountain-dwelling bird-like race, of questionable intelligence, who are susceptible to the effects of "ghost winds". Though they are mentioned as a background element in many of the books, the Ya-men are a critical plot element in Two to Conquer , The Winds of Darkover , and Cynthia McQuillin's The Forest from The Keeper's Price . In A Darkover Retrospective , Bradley says, "... I have no idea what
3600-572: A multitude of similar-sized objects. As described above, this characteristic was mandated as part of the IAU 's official definition of a planet in August 2006. Although to date this criterion only applies to the Solar System, a number of young extrasolar systems have been found in which evidence suggests orbital clearing is taking place within their circumstellar discs . Gravity causes planets to be pulled into
3744-501: A mystical conversation that she does not fully understand. Later she perceives telepathic contact with Andrew Carr. Shortly thereafter, they are rescued. Alessandro Li is also rescued and persuaded to advocate for the removal of Russell Montray, in favor of a competent legate. He agrees to make no trouble for Carr. Inquires are made about Peter Haldane; Jaelle did not killed him. Li agrees to arrange her divorce. Magda has another hallucination of mystical voices, who identify themselves as
3888-402: A negligible axial tilt as a result of their proximity to their stars. Similarly, the axial tilts of the planetary-mass moons are near zero, with Earth's Moon at 6.687° as the biggest exception; additionally, Callisto's axial tilt varies between 0 and about 2 degrees on timescales of thousands of years. The planets rotate around invisible axes through their centres. A planet's rotation period
4032-527: A part of the Empire. Hastur states that the decision of the Comyn was to preserve the Darkovan way of life and not become another satellite state of the Empire. Valdrin counters that Terran technology needs to be adopted since Darkover's matrix technology has been declining and Terran technology can replace it, or Darkover might sink into another Age of Chaos. This is a major plot point, as Arilinn Tower then engages to do
4176-529: A person from another star system. In Sharra's Exile , the Keeper Ashara explains that matrix mechanics , that is, the scientific use of laran amplified by matrix stones, is the first of the non-causal sciences. The Towers are the centers of the use of laran and schools for those who are learning to use their laran . A designated person is always on duty ("in the relays") to exchange news and requests for help telepathically with other Towers. At least once,
4320-413: A planet reaches a mass somewhat larger than Mars's mass, it begins to accumulate an extended atmosphere , greatly increasing the capture rate of the planetesimals by means of atmospheric drag . Depending on the accretion history of solids and gas, a giant planet , an ice giant , or a terrestrial planet may result. It is thought that the regular satellites of Jupiter, Saturn, and Uranus formed in
4464-426: A plausible base for future human exploration . Titan has the only nitrogen -rich planetary atmosphere in the Solar System other than Earth's. Just as Earth's conditions are close to the triple point of water, allowing it to exist in all three states on the planet's surface, so Titan's are to the triple point of methane . Planetary atmospheres are affected by the varying insolation or internal energy, leading to
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4608-457: A roughly spherical shape, so a planet's size can be expressed roughly by an average radius (for example, Earth radius or Jupiter radius ). However, planets are not perfectly spherical; for example, the Earth's rotation causes it to be slightly flattened at the poles with a bulge around the equator . Therefore, a better approximation of Earth's shape is an oblate spheroid , whose equatorial diameter
4752-424: A self-sustaining human population. Like Cottman V, Darkover is a planet stuck in a permanent ice age . Only one small equatorial strip of its single small continent is warm enough to support limited agriculture, fishing, and livestock. Similar in size to Earth, Darkover has a lower gravity due to its relative lack of metals; it also has a higher percentage of oxygen in the atmosphere. The planet's period of rotation
4896-454: A significant impact on mythology , religious cosmology , and ancient astronomy . In ancient times, astronomers noted how certain lights moved across the sky, as opposed to the " fixed stars ", which maintained a constant relative position in the sky. Ancient Greeks called these lights πλάνητες ἀστέρες ( planētes asteres ) ' wandering stars ' or simply πλανῆται ( planētai ) ' wanderers ' from which today's word "planet"
5040-449: A significantly lower mass than the gas giants (only 14 and 17 Earth masses). Dwarf planets are gravitationally rounded, but have not cleared their orbits of other bodies . In increasing order of average distance from the Sun, the ones generally agreed among astronomers are Ceres , Orcus , Pluto , Haumea , Quaoar , Makemake , Gonggong , Eris , and Sedna . Ceres is the largest object in
5184-407: A similar way; however, Triton was likely captured by Neptune, and Earth's Moon and Pluto's Charon might have formed in collisions. When the protostar has grown such that it ignites to form a star, the surviving disk is removed from the inside outward by photoevaporation , the solar wind , Poynting–Robertson drag and other effects. Thereafter there still may be many protoplanets orbiting
5328-467: A terrestrial planet could sustain liquid water on its surface, given enough atmospheric pressure. One in five Sun-like stars is thought to have an Earth-sized planet in its habitable zone, which suggests that the nearest would be expected to be within 12 light-years distance from Earth. The frequency of occurrence of such terrestrial planets is one of the variables in the Drake equation , which estimates
5472-478: Is 28 hours. One Darkover year is roughly equal to fifteen Earth months. Darkover's weather is affected by two major forces: The planet is dominated by polar icecaps and glaciers that cover most of its surface. The habitable area, just a few degrees north of the equator, joins the northern polar icecap on its northern and eastern side. Glaciers and impassible mountains (The Wall Around the World) prevent travel outside of
5616-438: Is 43 kilometers (27 mi) larger than the pole -to-pole diameter. Generally, a planet's shape may be described by giving polar and equatorial radii of a spheroid or specifying a reference ellipsoid . From such a specification, the planet's flattening, surface area, and volume can be calculated; its normal gravity can be computed knowing its size, shape, rotation rate, and mass. A planet's defining physical characteristic
5760-647: Is a servant in the Alton townhouse in Thendara. Although the Kyrri can understand human speech, they do not speak themselves, and in Sharra's Exile Regis Hastur wonders how the message he gave one would be delivered. The Trailmen are described as social herbivores who dwell in arboreal communities and live in extended family clans. Unattached females form bands of ronin who wander the forests attacking travelers. These Trailmen-human cause
5904-518: Is also frequently mentioned, the Ya-men, but Bradley leaves ambiguous the question of whether these creatures are sapient or not. The Catmen are the primary antagonists in The Spell Sword and feature in a number of the short stories. In The Spell Sword , Bradley describes them as carrying short, curved swords, capable of coordinating attacks against the humans, and able to use laran and starstones. The Catmen also featured prominently in several of
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6048-405: Is asked by the legate, Russell Montray, if she can help one of his agents pass as a native. Magda meets with Mother Lauria at the guildhouse and learns the rules under which she will be living for the next six months. An injured woman named Keitha knocks at the door and asks to take the oath, which will grant her refuge from her husband and family. Several days later, Magda, Doria and Keitha undergo
6192-715: Is at Caer Donn. Nevarsin is a retreat and a center of learning administered by the monks of St. Valentine of the Snows, a monastery founded by Father Valentine following a tragic event in Darkover Landfall . Storn is a castle (located on Storn Heights) and the Storn family was important in Stormqueen! and The Winds of Darkover . Shainsa is the chief of the Dry Towns and figures significantly in The Shattered Chain . The name Neskaya
6336-543: Is delineated by a set of elements: Planets have varying degrees of axial tilt; they spin at an angle to the plane of their stars' equators. This causes the amount of light received by each hemisphere to vary over the course of its year; when the Northern Hemisphere points away from its star, the Southern Hemisphere points towards it, and vice versa. Each planet therefore has seasons , resulting in changes to
6480-425: Is derived from "New Skye", the first settlement, near the place where the original colonizing ship crashed. Darkover's metal resources are scarce. Gold and silver are known but not in any quantity, and the most valuable metal is copper. Wealthy women have "butterfly clasps" for their hair made of copper; poorer women make do with something fashioned of leather and wood. Iron is more common, but very valuable because it
6624-458: Is known as a stellar day . Most of the planets in the Solar System rotate in the same direction as they orbit the Sun, which is counter-clockwise as seen from above the Sun's north pole . The exceptions are Venus and Uranus, which rotate clockwise, though Uranus's extreme axial tilt means there are differing conventions on which of its poles is "north", and therefore whether it is rotating clockwise or anti-clockwise. Regardless of which convention
6768-402: Is leaving, Montray makes a scene, betraying his incompetence. Magda resigns, in part because she realizes her skills will never be fully valued because she is female. Jaelle tells Peter that their marriage was a mistake, that she wants to divorce. When he cannot persuade her to change her mind, he hurls insults at her. Their discussion is interrupted by a loudspeaker page. Lady Rohana has come to
6912-470: Is that it is massive enough for the force of its own gravity to dominate over the electromagnetic forces binding its physical structure, leading to a state of hydrostatic equilibrium . This effectively means that all planets are spherical or spheroidal. Up to a certain mass, an object can be irregular in shape, but beyond that point, which varies depending on the chemical makeup of the object, gravity begins to pull an object towards its own centre of mass until
7056-450: Is that twins often have differing amounts of the family gifts. One twin usually has more of the gifts than does the other twin. Walter Breen cites Christopher Gibson for the observation that comyn is derived from the Gaelic word, comhionnan, meaning equal, and appears to refer to the communal origins of Darkover. A Comyn family frequently fosters a child from another Comyn family, at least for
7200-599: Is the Darkovan word for telepathic talent and the talents associated with it: telekinesis, precognition, a "sixth sense", empathy, teleportation, and others. It is the distinguishing feature of the people of Darkover. Although it appears mostly in Comyn, others may have it. It appears mostly in people who have red hair, and generally manifests itself at the time of puberty. Elorie Ardais, in The Bloody Sun , Chapter 7, says, "Everyone alive has some small degree of laran ". Damon Ridenow, in The Spell Sword , Chapter 6, reflects on
7344-437: Is the largest known detached object , a population that never comes close enough to the Sun to interact with any of the classical planets; the origins of their orbits are still being debated. All nine are similar to terrestrial planets in having a solid surface, but they are made of ice and rock rather than rock and metal. Moreover, all of them are smaller than Mercury, with Pluto being the largest known dwarf planet and Eris being
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#17328765676017488-500: Is the smallest object generally agreed to be a geophysical planet , at about six millionths of Earth's mass, though there are many larger bodies that may not be geophysical planets (e.g. Salacia ). An exoplanet is a planet outside the Solar System. As of 24 July 2024, there are 7,026 confirmed exoplanets in 4,949 planetary systems , with 1007 systems having more than one planet . Known exoplanets range in size from gas giants about twice as large as Jupiter down to just over
7632-421: Is the smallest, at 0.055 Earth masses. The planets of the Solar System can be divided into categories based on their composition. Terrestrials are similar to Earth, with bodies largely composed of rock and metal: Mercury, Venus, Earth, and Mars. Earth is the largest terrestrial planet. Giant planets are significantly more massive than the terrestrials: Jupiter, Saturn, Uranus, and Neptune. They differ from
7776-473: Is used for swords and horseshoes. In City of Sorcery , a man locks up his market stall, and the yet unnamed narrator, a Terran woman in Darkovan clothing, thinks he is prosperous, because "he can afford a Terran metal lock". Since some men carry swords, and most men and many women carry knives, presumably made of iron, this seems to be somewhat contradictory. Perhaps it is the Terran craftsmanship and technology, not
7920-457: Is used, Uranus has a retrograde rotation relative to its orbit. The rotation of a planet can be induced by several factors during formation. A net angular momentum can be induced by the individual angular momentum contributions of accreted objects. The accretion of gas by the giant planets contributes to the angular momentum. Finally, during the last stages of planet building, a stochastic process of protoplanetary accretion can randomly alter
8064-699: The Comyn . In Star of Danger , the Chieri who aids Kennard Alton and Larry Montray, tells them that the Chieri share common ancestors with the Trailmen and the Kyrri , though not with the Terrans. The Chieri feature prominently in The World Wreckers , The Planet Savers , Star of Danger , and in the long-lived, half-human/half-Chieri characters, Robert Kadarin and Thyra Scott, who appear in The Heritage of Hastur and Sharra's Exile . The Cralmac are semi-intelligent beings, artificially bred by humans during
8208-460: The Sun , Moon , and five points of light visible to the naked eye that moved across the background of the stars—namely, Mercury, Venus, Mars, Jupiter, and Saturn. Planets have historically had religious associations: multiple cultures identified celestial bodies with gods, and these connections with mythology and folklore persist in the schemes for naming newly discovered Solar System bodies. Earth itself
8352-520: The asteroid belt , located between the orbits of Mars and Jupiter. The other eight all orbit beyond Neptune. Orcus, Pluto, Haumea, Quaoar, and Makemake orbit in the Kuiper belt , which is a second belt of small Solar System bodies beyond the orbit of Neptune. Gonggong and Eris orbit in the scattered disc , which is somewhat further out and, unlike the Kuiper belt, is unstable towards interactions with Neptune. Sedna
8496-454: The climate over the course of its year. The time at which each hemisphere points farthest or nearest from its star is known as its solstice . Each planet has two in the course of its orbit; when one hemisphere has its summer solstice with its day being the longest, the other has its winter solstice when its day is shortest. The varying amount of light and heat received by each hemisphere creates annual changes in weather patterns for each half of
8640-563: The Ages of Chaos, from Trailmen altered with human DNA. They usually feature in the Darkovan novels as the servants of laranzu'in working in the towers, with the explanation that theirs is the only touch humans in the hyper-sensitive state of the matrix worker can bear. The Cralmac feature prominently in Patricia B. Cirone's Victory's Cost from Towers of Darkover . The Forge-Folk are not particularly well defined, though they are described as about
8784-577: The Aillard domain, which passes through female hands. She explains that Jaelle has no choice; it is the law of the Comyn. A fire breaks out on Alton lands. A number of Renunciates volunteer to help fight the fire, including Magda. They meet Damon Ridenow, Regent of Alton, and Andrew Carr, a Terran married to Ridenow's sister-in-law (from The Forbidden Tower ). Carr recognizes Magda as an Intelligence operative, but does not give her away. Magda realizes that Ridenow and Carr treat those around them as equals, unlike
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#17328765676018928-592: The Comyn for changes in policy or for assistance. In The Bloody Sun , Chapter 9, a group of Darkovans calling themselves the Pan-Darkovan Syndicate meets with Danvan Hastur and the members of the Arilinn Tower, and raises objections to the decision of the Comyn to limit trade and imports from the Terran Empire. Their spokesperson, Valdrin of Carthon, says they want some of the advantages that come with being
9072-511: The Dark Sisterhood, working for the long-term survival of Darkover. She also foresees that Jaelle will become pregnant by Damon Ridenow (Cleindori Aillard). t Darkover#The Renunciates Darkover is the planet that gives its name to the Darkover series of science fiction - fantasy novels and short stories by Marion Zimmer Bradley and others published since 1958. According to
9216-458: The Guildhouse of the Renuniciates at Thendera. Cholayna tries to talk her out of resigning, and Magda agrees to detached duty. Jaelle n'ha Melora starts her first day of working in the spaceport, but finds conforming to Terran customs a challenge. She quickly discovers that her new husband, Peter Haldane, despite being raised on Darkover, has typically Terran sexist attitudes towards women. Jaelle
9360-453: The Guildhouse to allow some of the Reuniciates to work in the spaceport. After a private meeting with Mother Lauria, Jaelle joins the house meeting, which is a combination disciplinary hearing and consciousness-raising session. Afterwards, Jaelle mentions one guild member who is away on Sisterhood business, explaining that this organization is a remnant of one of the original groups that founded
9504-626: The Kilghard Hills after Li. In the storm, kireseth pollen is disturbed, giving Jaelle a vision of her daughter, Cleindori, in red Keeper's robes. She hears Magda's voice encouraging her, but believes her to be another vision. Eventually the two women find shelter in a cave, and Jaelle realizes that Magda has come after her, because of her own premonition of Jaelle's death. Jaelle and Magda ponder their failures – as married women, as Renunciates. Jaelle realizes that she doesn't really want Peter's baby. Several days later, she miscarries. Magda hallucinates
9648-610: The Moon, Mercury, Venus, the Sun, Mars, Jupiter, and Saturn. After the fall of the Western Roman Empire , astronomy developed further in India and the medieval Islamic world. In 499 CE, the Indian astronomer Aryabhata propounded a planetary model that explicitly incorporated Earth's rotation about its axis, which he explains as the cause of what appears to be an apparent westward motion of
9792-588: The Moon. The smallest object in the Solar System generally agreed to be a geophysical planet is Saturn's moon Mimas, with a radius about 3.1% of Earth's and a mass about 0.00063% of Earth's. Saturn's smaller moon Phoebe , currently an irregular body of 1.7% Earth's radius and 0.00014% Earth's mass, is thought to have attained hydrostatic equilibrium and differentiation early in its history before being battered out of shape by impacts. Some asteroids may be fragments of protoplanets that began to accrete and differentiate, but suffered catastrophic collisions, leaving only
9936-622: The Priestesses of Avarra, a cloistered order that offered medical and other care to women, primarily abused women. Towards the end of Two to Conquer , Carlina di Asturien comes to believe that the two guilds need to work together for the benefit of all women on Darkover. Bradley acknowledged a Patricia Matthews fan story as the origin of the Sisterhood of the Sword, and described the Priesthood of Avarra as
10080-410: The Renunciates. A diplomatic function is arranged between Danvan Hastur and a group of Terran officials. Russell Montray and Alessandro Li manage to offend their Darkovan hosts over the issue of airspace and local control. Lorill Hastur and Rohana Ardais arrive, and Rohana asks to speak privately with Jaelle. Rohana notes that Jaelle is pregnant with a daughter, and that this daughter will be the heir to
10224-452: The Solar System is to the Sun. Mercury, the closest planet to the Sun at 0.4 AU , takes 88 days for an orbit, but ultra-short period planets can orbit in less than a day. The Kepler-11 system has five of its planets in shorter orbits than Mercury's, all of them much more massive than Mercury. There are hot Jupiters , such as 51 Pegasi b, that orbit very close to their star and may evaporate to become chthonian planets , which are
10368-404: The Solar System planets except Mercury have substantial atmospheres because their gravity is strong enough to keep gases close to the surface. Saturn's largest moon Titan also has a substantial atmosphere thicker than that of Earth; Neptune's largest moon Triton and the dwarf planet Pluto have more tenuous atmospheres. The larger giant planets are massive enough to keep large amounts of
10512-491: The Solar System, but in multitudes of other extrasolar systems. The consensus as to what counts as a planet, as opposed to other objects, has changed several times. It previously encompassed asteroids , moons , and dwarf planets like Pluto , and there continues to be some disagreement today. The five classical planets of the Solar System , being visible to the naked eye, have been known since ancient times and have had
10656-489: The Solar System, whereas others are commonly observed in exoplanets. In the Solar System, all the planets orbit the Sun in the same direction as the Sun rotates : counter-clockwise as seen from above the Sun's north pole. At least one exoplanet, WASP-17b , has been found to orbit in the opposite direction to its star's rotation. The period of one revolution of a planet's orbit is known as its sidereal period or year . A planet's year depends on its distance from its star;
10800-516: The Terran zone to confront Jaelle about her duties to the Aillard Domain. As she decides to leave the Terran zone entirely, she learns that Alessandro Li has undertaken a journey to the Kilghard Hills without an escort. She determines to follow him, but Peter threatens to have the Terran authorities lock her up on the grounds that she is pregnant. Frightened, she throws him to the floor, and leaves believing that she has killed him. Jaelle rides into
10944-467: The Terrans wonder how news travels so fast on Darkover. Towers are, in theory, independent of any caste discrimination or political influence. Each Tower should have a Keeper, a person to direct both Tower policy and the power of the laran users when they gather together in rapport to work. The Keeper of Arilinn is considered the second most-powerful person on Darkover, after the Hastur regent. One who goes to
11088-538: The Ya-Men were — or are — like. I only know that they are very terrible indeed, with plumes and talons and shrill yelping cries ..." This is a conscious decision; she thinks that monsters should not be described in too much detail, lest they lose their horror. Comyn is the term used for aristocratic members of Darkover society who are gifted with the psychic abilities commonly called laran. Comyn women may be referred to as Comynara, especially by commoners. The Comyn are
11232-402: The assistance of Terran surveys), but the effort, at first successful, is abandoned. The most important mineral on Darkover is the matrix stone or starstone, a jewel that the first colonists discover in Darkover Landfall . It has a deep blue color, and large ones are rare. Its composition is not known by anyone, and in fact it is theorized by some that it is a form of life. This jewel provides
11376-480: The atmospheric dynamics that affect the day-night temperature difference are complex. One important characteristic of the planets is their intrinsic magnetic moments , which in turn give rise to magnetospheres. The presence of a magnetic field indicates that the planet is still geologically alive. In other words, magnetized planets have flows of electrically conducting material in their interiors, which generate their magnetic fields. These fields significantly change
11520-649: The category of dwarf planet . Many planetary scientists have nonetheless continued to apply the term planet more broadly, including dwarf planets as well as rounded satellites like the Moon. Further advances in astronomy led to the discovery of over five thousand planets outside the Solar System, termed exoplanets . These often show unusual features that the Solar System planets do not show, such as hot Jupiters —giant planets that orbit close to their parent stars, like 51 Pegasi b —and extremely eccentric orbits , such as HD 20782 b . The discovery of brown dwarfs and planets larger than Jupiter also spurred debate on
11664-559: The collapse of a nebula into a thin disk of gas and dust. A protostar forms at the core, surrounded by a rotating protoplanetary disk . Through accretion (a process of sticky collision) dust particles in the disk steadily accumulate mass to form ever-larger bodies. Local concentrations of mass known as planetesimals form, and these accelerate the accretion process by drawing in additional material by their gravitational attraction. These concentrations become ever denser until they collapse inward under gravity to form protoplanets . After
11808-544: The conclusion of The Winds of Darkover , and are mentioned in several of the Sharra stories. The Kyrri are humanoid bipeds with grey or silver fur, simian faces and glowing green (or dark) eyes. Perhaps they are the result of genetic engineering during the Ages of Chaos , or they may be a native species from the pre-history of Darkover. In Sharra's Exile , Book Two, Chapter 5, Regis Hastur speculates that even tower workers do not know
11952-476: The cross-species transmission of a 48-year cyclic illness known as Trailmen's Fever, which is mild in Trailmen and often fatal in humans. The Chieri call the Trailmen a word that means "The Little Brothers Who Are Not Wise". The Trailmen feature prominently in the novels, The Planet Savers and Star of Danger , and in Diana L. Paxson's short story, The Place Between , from Snows of Darkover . The Ya-men are
12096-406: The definition, regarding where exactly to draw the line between a planet and a star. Multiple exoplanets have been found to orbit in the habitable zones of their stars (where liquid water can potentially exist on a planetary surface ), but Earth remains the only planet known to support life . It is not known with certainty how planets are formed. The prevailing theory is that they coalesce during
12240-473: The eight planets in the Solar System, only Venus and Mars lack such a magnetic field. Of the magnetized planets, the magnetic field of Mercury is the weakest and is barely able to deflect the solar wind . Jupiter's moon Ganymede has a magnetic field several times stronger, and Jupiter's is the strongest in the Solar System (so intense in fact that it poses a serious health risk to future crewed missions to all its moons inward of Callisto ). The magnetic fields of
12384-464: The expectation of male protection. In later books, "Free Amazons" is considered to be a misnomer and insulting or opprobrious, but the Renunciates themselves are tolerant of those who use "Free Amazons" out of ignorance. The origins of this guild during the Hundred Kingdoms era are described in Two to Conquer as the merger between the Sisterhood of the Sword, a military -mercenary guild, and
12528-418: The farther a planet is from its star, the longer the distance it must travel and the slower its speed, since it is less affected by its star's gravity . No planet's orbit is perfectly circular, and hence the distance of each from the host star varies over the course of its year. The closest approach to its star is called its periastron , or perihelion in the Solar System, whereas its farthest separation from
12672-522: The formation of dynamic weather systems such as hurricanes (on Earth), planet-wide dust storms (on Mars), a greater-than-Earth-sized anticyclone on Jupiter (called the Great Red Spot ), and holes in the atmosphere (on Neptune). Weather patterns detected on exoplanets include a hot region on HD 189733 b twice the size of the Great Red Spot, as well as clouds on the hot Jupiter Kepler-7b ,
12816-626: The giant planets have numerous moons in complex planetary-type systems. Except for Ceres and Sedna, all the consensus dwarf planets are known to have at least one moon as well. Many moons of the giant planets have features similar to those on the terrestrial planets and dwarf planets, and some have been studied as possible abodes of life (especially Europa and Enceladus). The four giant planets are orbited by planetary rings of varying size and complexity. The rings are composed primarily of dust or particulate matter, but can host tiny ' moonlets ' whose gravity shapes and maintains their structure. Although
12960-467: The giant planets the mantle simply blends into the upper cloud layers. The terrestrial planets have cores of elements such as iron and nickel and mantles of silicates . Jupiter and Saturn are believed to have cores of rock and metal surrounded by mantles of metallic hydrogen . Uranus and Neptune, which are smaller, have rocky cores surrounded by mantles of water, ammonia , methane , and other ices . The fluid action within these planets' cores creates
13104-417: The grounds that the internal physics of objects does not change between approximately one Saturn mass (beginning of significant self-compression) and the onset of hydrogen burning and becoming a red dwarf star. Beyond roughly 13 M J (at least for objects with solar-type isotopic abundance ), an object achieves conditions suitable for nuclear fusion of deuterium : this has sometimes been advocated as
13248-405: The habitable lands. Darkover's nominally temperate continental zone, which borders the open water of the planet's ocean, is nevertheless subject to severe winter weather, and warm days in summer are rare. The temperate portion of the continent is dominated by evergreen forests that grow in the mountain foothills. These trees contain a flammable resin which contributes to frequent forest fires during
13392-416: The interaction of the planet and solar wind. A magnetized planet creates a cavity in the solar wind around itself called the magnetosphere, which the wind cannot penetrate. The magnetosphere can be much larger than the planet itself. In contrast, non-magnetized planets have only small magnetospheres induced by interaction of the ionosphere with the solar wind, which cannot effectively protect the planet. Of
13536-509: The largest member of the collection of icy bodies known as the Kuiper belt . The discovery of other large objects in the Kuiper belt, particularly Eris , spurred debate about how exactly to define a planet. In 2006, the International Astronomical Union (IAU) adopted a definition of a planet in the Solar System, placing the four terrestrial planets and the four giant planets in the planet category; Ceres, Pluto, and Eris are in
13680-520: The leftover cores. There are also exoplanets that are much farther from their star. Neptune is 30 AU from the Sun and takes 165 years to orbit, but there are exoplanets that are thousands of AU from their star and take more than a million years to orbit (e.g. COCONUTS-2b ). Although each planet has unique physical characteristics, a number of broad commonalities do exist among them. Some of these characteristics, such as rings or natural satellites, have only as yet been observed in planets in
13824-447: The light gases hydrogen and helium, whereas the smaller planets lose these gases into space . Analysis of exoplanets suggests that the threshold for being able to hold on to these light gases occurs at about 2.0 +0.7 −0.6 M E , so that Earth and Venus are near the maximum size for rocky planets. The composition of Earth's atmosphere is different from the other planets because the various life processes that have transpired on
13968-501: The likelihood that a star will have planets. Hence, a metal-rich population I star is more likely to have a substantial planetary system than a metal-poor, population II star . According to the IAU definition , there are eight planets in the Solar System, which are (in increasing distance from the Sun): Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. Jupiter is the largest, at 318 Earth masses , whereas Mercury
14112-480: The magnetosphere of an orbiting hot Jupiter. Several planets or dwarf planets in the Solar System (such as Neptune and Pluto) have orbital periods that are in resonance with each other or with smaller bodies. This is common in satellite systems (e.g. the resonance between Io, Europa , and Ganymede around Jupiter, or between Enceladus and Dione around Saturn). All except Mercury and Venus have natural satellites , often called "moons". Earth has one, Mars has two, and
14256-458: The matrix stone is attuned will be able to open the box. Most persons with laran have a matrix stone that they carry in a small bag or pouch made of silk or leather, which are "insulators". Usually, the pouch is worn around the neck as a pendant. In general, the larger the stone, the more it can amplify the user's laran . Matrix stones can be used to power aircraft or make a person invisible ( The Bloody Sun ). Trained matrix mechanics can create
14400-524: The metal, that makes the lock valuable. In The Bloody Sun , the matrix workers at Ariliin agree to do a geological survey using their powers, to forestall a survey that otherwise would be done by the Terrans. They are to search for "tin, copper, silver, iron, tungsten" and for "fuels, for sulfur, hydrocarbons, chemicals". The purpose is to prevent Terrans and their "infernal machines" from spreading across Darkover. They succeed in locating mineral deposits and marking them on maps (ironically, maps created using
14544-582: The most massive. There are at least nineteen planetary-mass moons or satellite planets—moons large enough to take on ellipsoidal shapes: The Moon, Io, and Europa have compositions similar to the terrestrial planets; the others are made of ice and rock like the dwarf planets, with Tethys being made of almost pure ice. Europa is often considered an icy planet, though, because its surface ice layer makes it difficult to study its interior. Ganymede and Titan are larger than Mercury by radius, and Callisto almost equals it, but all three are much less massive. Mimas
14688-457: The novels, Darkover is the only habitable planet of seven orbiting a fictional red giant star called Cottman. Bradley describes Cottman's Star as a red giant , around which seven planets orbit. Among these, Cottman IV, known to its inhabitants as Darkover, is the only habitable planet. The three inner planets and two outer planets are not habitable. Cottman V is an ice planet that while not toxic to humans, cannot naturally support
14832-537: The number of intelligent, communicating civilizations that exist in the Milky Way. There are types of planets that do not exist in the Solar System: super-Earths and mini-Neptunes , which have masses between that of Earth and Neptune. Objects less than about twice the mass of Earth are expected to be rocky like Earth; beyond that, they become a mixture of volatiles and gas like Neptune. The planet Gliese 581c , with
14976-420: The oath is called her "oath-mother". Magdalene Lorne takes the name Margali n'ha Ysabet: Margali is a Darkovan version of her Terran name, Magdalene (she is also called Magda), and her mother's name was Elizabeth. Camilla, born Elorie Lindir, takes the name Camilla n'ha Kyria, because her mother was Kyria Aillard. Had she been legitimate or acknowledged as nedestro , her name might have been Elorie Hastur. Laran
15120-414: The object collapses into a sphere. Mass is the prime attribute by which planets are distinguished from stars. No objects between the masses of the Sun and Jupiter exist in the Solar System, but there are exoplanets of this size. The lower stellar mass limit is estimated to be around 75 to 80 times that of Jupiter ( M J ). Some authors advocate that this be used as the upper limit for planethood, on
15264-466: The odd fact that Andrew Carr, a Terran, has laran , and can telepathically be in touch with Callista when he and Callista's twin sister cannot: In the telepath caste, it was often the accident of possessing laran , the specific telepath Gift, which determined how close a relationship would come. Caste, family, social position, all these became irrelevant compared to that one compelling fact; one had, or one did not, that inborn power, and in consequence one
15408-401: The origins of planetary rings are not precisely known, they are believed to be the result of natural satellites that fell below their parent planets' Roche limits and were torn apart by tidal forces . The dwarf planets Haumea and Quaoar also have rings. No secondary characteristics have been observed around exoplanets. The sub-brown dwarf Cha 110913−773444 , which has been described as
15552-507: The origins of the Kyrri . Kyrri generate a bioelectric field and sometimes give painful but non-lethal electric shocks when excited or threatened. The Kyrri appear in The Bloody Sun , Star of Danger , and The Sword of Aldones , and also in Sharra's Exile , the replacement for the latter book. They are used primarily as servants in the Towers because they can pass through the barriers that non-telepathic humans cannot. In The Bloody Sun , one
15696-399: The other Comyn nobility she has met. Eventually her burns are healed by Hilary Castamir-Sytris (from Marion Zimmer Bradley's Darkover ). Russell Montray and Alessandro Li become obsessed with meeting Andrew Carr, now called An’ndra Lanart. Despite Magda, Peter and others explaining the breach of etiquette this could cause, they are insistent. Magda realizes that Carr must be warned. As Carr
15840-486: The other giant planets, measured at their surfaces, are roughly similar in strength to that of Earth, but their magnetic moments are significantly larger. The magnetic fields of Uranus and Neptune are strongly tilted relative to the planets' rotational axes and displaced from the planets' centres. In 2003, a team of astronomers in Hawaii observing the star HD 179949 detected a bright spot on its surface, apparently created by
15984-761: The other in perpetual night. Mercury and Venus, the closest planets to the Sun, similarly exhibit very slow rotation: Mercury is tidally locked into a 3:2 spin–orbit resonance (rotating three times for every two revolutions around the Sun), and Venus's rotation may be in equilibrium between tidal forces slowing it down and atmospheric tides created by solar heating speeding it up. All the large moons are tidally locked to their parent planets; Pluto and Charon are tidally locked to each other, as are Eris and Dysnomia, and probably Orcus and its moon Vanth . The other dwarf planets with known rotation periods rotate faster than Earth; Haumea rotates so fast that it has been distorted into
16128-713: The others. Renk says that Bradley appears to have a mental model when she writes, but not a map in the ordinary sense. Some cities or locations on the map are associated with the seven Domains: Hastur with the Hasturs; Armida with the Altons; Ardais with the Ardais; Serrais with the Ridenow; and Aldaran with the Aldarans. In Traitor's Sun , Chapter 3, the Domain of Elhalyn is described as stretching "from
16272-420: The planet have introduced free molecular oxygen . The atmospheres of Mars and Venus are both dominated by carbon dioxide , but differ drastically in density: the average surface pressure of Mars's atmosphere is less than 1% that of Earth's (too low to allow liquid water to exist), while the average surface pressure of Venus's atmosphere is about 92 times that of Earth's. It is likely that Venus's atmosphere
16416-597: The planet. Jupiter's axial tilt is very small, so its seasonal variation is minimal; Uranus, on the other hand, has an axial tilt so extreme it is virtually on its side, which means that its hemispheres are either continually in sunlight or continually in darkness around the time of its solstices . In the Solar System, Mercury, Venus, Ceres, and Jupiter have very small tilts; Pallas, Uranus, and Pluto have extreme ones; and Earth, Mars, Vesta, Saturn, and Neptune have moderate ones. Among exoplanets, axial tilts are not known for certain, though most hot Jupiters are believed to have
16560-620: The planets as the Babylonians. In the 6th and 5th centuries BC, the Pythagoreans appear to have developed their own independent planetary theory , which consisted of the Earth, Sun, Moon, and planets revolving around a "Central Fire" at the center of the Universe. Pythagoras or Parmenides is said to have been the first to identify the evening star ( Hesperos ) and morning star ( Phosphoros ) as one and
16704-475: The positions of the planets. These schemes, which were based on geometry rather than the arithmetic of the Babylonians, would eventually eclipse the Babylonians' theories in complexity and comprehensiveness and account for most of the astronomical movements observed from Earth with the naked eye. These theories would reach their fullest expression in the Almagest written by Ptolemy in the 2nd century CE. So complete
16848-457: The return of his wife. When the Reunciates refuse, a fight ensues. Magda kills one of the mercenaries and comes close to killing the second before Camilla stops her; Magda's failure to follow Darkovan codes of conduct have indebted the Guildhouse to pay steep damages for her mistakes. Magda continues to struggle with the expectations of her Renunciate sisters. Cholayna asks Jaelle to intercede with
16992-435: The roof with materials and tools. The highest degree is Keeper, but generally women are trained for this arduous position from a young age. Not many young women want to undergo this. A Keeper is the center of a group of laran workers, who accepts the energy ("energons") that they generate and directs it. Planet A planet is a large, rounded astronomical body that is generally required to be in orbit around
17136-736: The same ( Aphrodite , Greek corresponding to Latin Venus ), though this had long been known in Mesopotamia. In the 3rd century BC, Aristarchus of Samos proposed a heliocentric system, according to which Earth and the planets revolved around the Sun. The geocentric system remained dominant until the Scientific Revolution . By the 1st century BC, during the Hellenistic period , the Greeks had begun to develop their own mathematical schemes for predicting
17280-486: The same height and build as the Trailmen. Walter Breen's The Darkover Concordance describes them as a cross between humans and non-humans, who speak an ancient variant of the Hellers dialect. They are Darkover's primary miners and metalworkers. The Forge Folk worship the Sharra matrix , and appear to be the only creatures on Darkover capable of handling Sharra without causing catastrophe. The Forge-Folk feature prominently in
17424-463: The second millennium BC. The MUL.APIN is a pair of cuneiform tablets dating from the 7th century BC that lays out the motions of the Sun, Moon, and planets over the course of the year. Late Babylonian astronomy is the origin of Western astronomy and indeed all Western efforts in the exact sciences . The Enuma anu enlil , written during the Neo-Assyrian period in the 7th century BC, comprises
17568-449: The seven Domains. Each Comyn family controls part of Darkover's landmass, known as a Domain, but strategic inter-marriage and feudal land issues result in fluctuating domain borders. Each Comyn family has a gift — a family-specific laran power, though in reality, not every member of the family has the family gift. Also, a member of a family may have another family's gift, in whole or in part. The gifts may skip generations. Of particular note
17712-582: The short stories, including David Heydt's I'm a Big Cat Now from Towers of Darkover ; Linda Frankel and Paula Crunk's Blood Hunt from The Other Side of the Mirror ; and Judith Sampson's To Serve Kihar from Domains of Darkover . The Chieri are a race of six-fingered, tall, telepathic humanoids who have no permanent gender. Extremely long-lived, with life-spans reaching into the tens of thousands of years, they are described as gray or golden-eyed and with long, silvery-white hair. They will change sexes as
17856-432: The situation warrants for mating purposes. The World Wreckers describes the Chieri as the last, dying remnants of a space-traveling people whose abilities have dwindled with their fertility and ambition. Chieri and humans are similar biologically and are able to interbreed. These hybrids exhibit some of the Chieri characteristics of coloring and physiology. They also have psychic gifts, and their descendants become
18000-421: The size of Neptune and smaller, down to smaller than Mercury. In 2011, the Kepler space telescope team reported the discovery of the first Earth-sized exoplanets orbiting a Sun-like star , Kepler-20e and Kepler-20f . Since that time, more than 100 planets have been identified that are approximately the same size as Earth , 20 of which orbit in the habitable zone of their star—the range of orbits where
18144-501: The size of the Moon . Analysis of gravitational microlensing data suggests a minimum average of 1.6 bound planets for every star in the Milky Way . In early 1992, radio astronomers Aleksander Wolszczan and Dale Frail announced the discovery of two planets orbiting the pulsar PSR 1257+12 . This discovery was confirmed and is generally considered to be the first definitive detection of exoplanets. Researchers suspect they formed from
18288-413: The smaller planetesimals (as well as radioactive decay ) will heat up the growing planet, causing it to at least partially melt. The interior of the planet begins to differentiate by density, with higher density materials sinking toward the core . Smaller terrestrial planets lose most of their atmospheres because of this accretion, but the lost gases can be replaced by outgassing from the mantle and from
18432-470: The spin axis of the planet. There is great variation in the length of day between the planets, with Venus taking 243 days to rotate, and the giant planets only a few hours. The rotational periods of exoplanets are not known, but for hot Jupiters , their proximity to their stars means that they are tidally locked (that is, their orbits are in sync with their rotations). This means, they always show one face to their stars, with one side in perpetual day,
18576-400: The star is called its apastron ( aphelion ). As a planet approaches periastron, its speed increases as it trades gravitational potential energy for kinetic energy , just as a falling object on Earth accelerates as it falls. As the planet nears apastron, its speed decreases, just as an object thrown upwards on Earth slows down as it reaches the apex of its trajectory . Each planet's orbit
18720-523: The star or each other, but over time many will collide, either to form a larger, combined protoplanet or release material for other protoplanets to absorb. Those objects that have become massive enough will capture most matter in their orbital neighbourhoods to become planets. Protoplanets that have avoided collisions may become natural satellites of planets through a process of gravitational capture, or remain in belts of other objects to become either dwarf planets or small bodies . The energetic impacts of
18864-460: The subsequent impact of comets (smaller planets will lose any atmosphere they gain through various escape mechanisms ). With the discovery and observation of planetary systems around stars other than the Sun, it is becoming possible to elaborate, revise or even replace this account. The level of metallicity —an astronomical term describing the abundance of chemical elements with an atomic number greater than 2 ( helium )—appears to determine
19008-412: The super-Earth Gliese 1214 b , and others. Hot Jupiters, due to their extreme proximities to their host stars, have been shown to be losing their atmospheres into space due to stellar radiation, much like the tails of comets. These planets may have vast differences in temperature between their day and night sides that produce supersonic winds, although multiple factors are involved and the details of
19152-611: The surviving laran-gifted families of Darkover who are ruling at the time of recontact with the Terran Empire. It is suggested in Darkover Landfall that they are the descendants of human-chieri pairings, who have learned to use native matrix stones to focus their laran powers. The Comyn, however, have their own mythology, recited in the Ballad of Hastur and Cassilda : they are the descendants of Hastur, son of Aldones, Lord of Light, who fell to earth, fell in love with Cassilda, and (perhaps) became mortal. Cassilda bore Hastur seven sons who founded
19296-433: The terrestrial planets in composition. The gas giants , Jupiter and Saturn, are primarily composed of hydrogen and helium and are the most massive planets in the Solar System. Saturn is one third as massive as Jupiter, at 95 Earth masses. The ice giants , Uranus and Neptune, are primarily composed of low-boiling-point materials such as water, methane , and ammonia , with thick atmospheres of hydrogen and helium. They have
19440-739: The trainee is proficient at this, he is qualified to "monitor" other laran workers to ensure that they are not in danger when working, and takes the Monitor's Oath, with the approval of the members of the Tower. A person who is deemed morally or otherwise unfit to work with laran will not be allowed to take the oath and will be expelled from the tower without any more training. This apparently happened to Dyan Ardais. A matrix Mechanic learns to manipulate matter and energy using his laran and matrix stone, and to make and use tools that focus and augment laran. In The Bloody Sun Jeff Kerwin, just beginning his training as
19584-462: The warmer months. Further, southwest from the forests are Darkover's highlands, plains, salt marshes and arable river valleys. On the continent's far western side is another mountain range called "The Hellers" and a high elevation cold desert plateau called "The Dry Towns". Multiple conflicting attempts to map Darkover exist, including one in The Heritage of Hastur (1975) which Bradley repudiated in
19728-715: The west side of the Lake of Hali to the Sea of Dalereuth"; this is not on the map, nor is the Aillard Domain. Other names on the map are Towers: Hali, where the Tower was destroyed, but its burnt rubble and a small chapel, the Rhu Fead , remain; Arilinn; Dalereuth; and Neskaya. Thendara is the location of the Comyn Castle and its Tower, which was destroyed in Exile's Song , as well as the main Terran spaceport and administrative offices. Another Terran spaceport
19872-413: Was derived. In ancient Greece , China , Babylon , and indeed all pre-modern civilizations, it was almost universally believed that Earth was the center of the Universe and that all the "planets" circled Earth. The reasons for this perception were that stars and planets appeared to revolve around Earth each day and the apparently common-sense perceptions that Earth was solid and stable and that it
20016-416: Was found in 1992 in orbit around a pulsar . Its mass is roughly half that of the planet Mercury. Even smaller is WD 1145+017 b , orbiting a white dwarf; its mass is roughly that of the dwarf planet Haumea, and it is typically termed a minor planet. The smallest known planet orbiting a main-sequence star other than the Sun is Kepler-37b , with a mass (and radius) that is probably slightly higher than that of
20160-569: Was not moving but at rest. The first civilization known to have a functional theory of the planets were the Babylonians , who lived in Mesopotamia in the first and second millennia BC. The oldest surviving planetary astronomical text is the Babylonian Venus tablet of Ammisaduqa , a 7th-century BC copy of a list of observations of the motions of the planet Venus, that probably dates as early as
20304-420: Was recognized as a planet when heliocentrism supplanted geocentrism during the 16th and 17th centuries. With the development of the telescope , the meaning of planet broadened to include objects only visible with assistance: the moons of the planets beyond Earth; the ice giants Uranus and Neptune; Ceres and other bodies later recognized to be part of the asteroid belt ; and Pluto , later found to be
20448-436: Was stranger or kinfolk. By that criterion alone, the most important one on Darkover, Andrew Carr was one of them, and the fact that he was an Earthman was a small random fact without any real importance. Being telepathically connected to another is called being "in rapport". Elizabeth Mackintosh, a character in the novel Rediscovery , suggests the Darkovan language appears to be derived from old Terran languages. She proposes
20592-508: Was the domination of Ptolemy's model that it superseded all previous works on astronomy and remained the definitive astronomical text in the Western world for 13 centuries. To the Greeks and Romans, there were seven known planets, each presumed to be circling Earth according to the complex laws laid out by Ptolemy. They were, in increasing order from Earth (in Ptolemy's order and using modern names):
20736-458: Was the result of a runaway greenhouse effect in its history, which today makes it the hottest planet by surface temperature, hotter even than Mercury. Despite hostile surface conditions, temperature, and pressure at about 50–55 km altitude in Venus's atmosphere are close to Earthlike conditions (the only place in the Solar System beyond Earth where this is so), and this region has been suggested as
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