title: Human sexuality

text: Sexual attraction is attraction on the basis of sexual desire or the quality of arousing such interest. Sexual attractiveness or sex appeal is an individual's ability to attract the sexual or erotic interest of another person, and is a factor in sexual selection or mate choice. The attraction can be to the physical or other qualities or traits of a person, or to such qualities in the context in which they appear. The attraction may be to a person's aesthetics or movements or to their voice or smell, besides other factors. The attraction may be enhanced by a person's adornments, clothing, perfume, hair length and style, and anything else which can attract the sexual interest of another person. It can also be influenced by individual genetic, psychological, or cultural factors, or to other, more amorphous qualities of the person. Sexual attraction is also a response to another person that depends on a combination of the person possessing the traits and also on the criteria of the person who is attracted.


title: Human sexuality

text: Though attempts have been made to devise objective criteria of sexual attractiveness, and measure it as one of several bodily forms of capital asset ("see erotic capital"), a person's sexual attractiveness is to a large extent a subjective measure dependent on another person's interest, perception, and sexual orientation. For example, a gay or lesbian person would typically find a person of the same sex to be more attractive than one of the other sex. A bisexual person would find either sex to be attractive.


title: Human sexuality

text: In addition, there are asexual people, who usually do not experience sexual attraction for either sex, though they may have romantic attraction (homoromantic, biromantic or heteroromantic). Interpersonal attraction includes factors such as physical or psychological similarity, familiarity or possessing a preponderance of common or familiar features, similarity, complementarity, reciprocal liking, and reinforcement.


title: Human sexuality

text: The ability of a person's physical and other qualities to create a sexual interest in others is the basis of their use in advertising, music video, pornography, film, and other visual media, as well as in modeling, sex work and other occupations.


title: Human sexuality

text: Globally, laws regulate human sexuality in several ways, including criminalizing particular sexual behaviors, granting individuals the privacy or autonomy to make their own sexual decisions, protecting individuals with regard to equality and non-discrimination, recognizing and protecting other individual rights, as well as legislating matters regarding marriage and the family, and creating laws protecting individuals from violence, harassment, and persecution.


title: Human sexuality

text: In the United States, there are two fundamentally different approaches, applied in different states, regarding the way the law is used to attempt to govern a person's sexuality. The "black letter" approach to law focuses on the study of pre-existing legal precedent, and attempts to offer a clear framework of rules within which lawyers and others can work. In contrast, the socio-legal approach focuses more broadly on the relationship between the law and society, and offers a more contextualized view of the relationship between legal and social change.


title: Human sexuality

text: Issues regarding human sexuality and human sexual orientation came to the forefront in Western law in the latter half of the twentieth century, as part of the gay liberation movement's encouragement of LGBT individuals to "come out of the closet" and engage with the legal system, primarily through courts. Therefore, many issues regarding human sexuality and the law are found in the opinions of the courts.


title: Human sexuality

text: While the issue of privacy has been useful to sexual rights claims, some scholars have criticized its usefulness, saying that this perspective is too narrow and restrictive. The law is often slow to intervene in certain forms of coercive behavior that can limit individuals' control over their own sexuality (such as female genital mutilation, forced marriages or lack of access to reproductive health care). Many of these injustices are often perpetuated wholly or in part by private individuals rather than state agents, and as a result, there is an ongoing debate about the extent of state responsibility to prevent harmful practices and to investigate such practices when they do occur.


title: Human sexuality

text: State intervention with regards to sexuality also occurs, and is considered acceptable by some, in certain instances (e.g. same-sex sexual activity or prostitution).


title: Human sexuality

text: The legal systems surrounding prostitution are a topic of debate. Proponents for criminalization argue that sex work is an immoral practice that should not be tolerated, while proponents for decriminalization point out how criminalization does more harm than good. Within the feminist movement, there is also a debate over whether sex work is inherently objectifying and exploitative or whether sex workers have the agency to sell sex as a service.


title: Human sexuality

text: When sex work is criminalized, sex workers do not have support from law enforcement when they fall victim to violence. In a 2003 survey of street-based sex workers in NYC, 80% said they had been threatened with or experienced violence, and many said the police were no help. 27% said they had experienced violence from police officers themselves. Different identities such as being black, transgender, or poor can result in a person being more likely to be criminally profiled by the police. For example, in New York, there is a law against "loitering for the purpose of engaging in prostitution", which has been nicknamed the "walking while trans" law because of how often transgender women are assumed to be sex workers and arrested for simply walking out in public.


title: Human sexuality

text: In some religions, sexual behavior is regarded as primarily spiritual. In others it is treated as primarily physical. Some hold that sexual behavior is only spiritual within certain kinds of relationships, when used for specific purposes, or when incorporated into religious ritual. In some religions there are no distinctions between the physical and the spiritual, whereas some religions view human sexuality as a way of completing the gap that exists between the spiritual and the physical.


title: Human sexuality

text: Many religious conservatives, especially those of Abrahamic religions and Christianity in particular, tend to view sexuality in terms of behavior (i.e. homosexuality or heterosexuality is what someone does) and certain sexualities such as bisexuality tend to be ignored as a result of this. These conservatives tend to promote celibacy for gay people, and may also tend to believe that sexuality can be changed through conversion therapy or prayer to become an ex-gay. They may also see homosexuality as a form of mental illness, something that ought to be criminalised, an immoral abomination, caused by ineffective parenting, and view same-sex marriage as a threat to society.


title: Human sexuality

text: On the other hand, most religious liberals define sexuality-related labels in terms of sexual attraction and self-identification. They may also view same-sex activity as morally neutral and as legally acceptable as opposite-sex activity, unrelated to mental illness, genetically or environmentally caused (but not as the result of bad parenting), and fixed. They also tend to be more in favor of same-sex marriage.


title: Human sexuality

text: According to Judaism, sex between a man and woman within marriage is sacred and should be regularly enjoyed; celibacy is considered sinful.


title: Human sexuality

text: Desire, including sexual desire and lust, were considered immoral and sinful, according to some authors. Elaine Pagels says, "By the beginning of the fifth century, Augustine had actually declared that spontaneous sexual desire is the proof of—and penalty for—universal original sin", though that this view goes against "most of his Christian predecessors". According to Jennifer Wright Knust, Paul framed desire a force Christians gained control over whereas non-Christians were "enslaved" by it; and he also said the bodies of Christians were members of Christ's body and thus sexual desire must be eschewed.


title: Human sexuality

text: The Roman Catholic Church teaches that sexuality is "noble and worthy" and has a unitive and procreative end. For this reason, sexual activity's ideal should occur in the context of a marriage between a man and a woman, and open to the possibility of life. Pope Francis teaches in Amoris laetitia against "an attitude that would solve everything by applying general rules or deriving undue conclusions from particular theological considerations. and that he also warns that "not all discussions of doctrinal, moral or pastoral issues need to be settled by interventions of the magisterium." and that "We have been called to form consciences, not to replace them." The church has authoritative teachings on sexuality found in the catechism. The church places primacy of conscience especially on the regulation of births.


title: Human sexuality

text: The Anglican Church teaches that human sexuality is a gift from a loving God designed to be between a man and a woman in a monogamous lifetime union of marriage. It also views singleness and dedicated celibacy as Christ-like. It states that people with same sex attraction are loved by God and are welcomed as full members of the Body of Christ, while the Church leadership has a variety of views in regard to homosexual expression and ordination. Some expressions of sexuality are considered sinful including "promiscuity, prostitution, incest, pornography, paedophilia, predatory sexual behaviour, and sadomasochism (all of which may be heterosexual and homosexual), adultery, violence against wives, and female circumcision". The Church is concerned with pressures on young people to engage sexually and encourages abstinence.


title: Human sexuality

text: In matters of sexuality, several Evangelical churches promote the virginity pledge among young Evangelical Christians, who are invited to commit themselves during a public ceremony to sexual abstinence until Christian marriage. This pledge is often symbolized by a purity ring.


title: Human sexuality

text: In evangelical churches, young adults and unmarried couples are encouraged to marry early in order to live a sexuality according to the will of God.


title: Human sexuality

text: Although some churches are discreet on the subject, other evangelical churches in United States and Switzerland speak of a satisfying sexuality as a gift from God and a component of a harmonious Christian marriage, in messages during worship services or conferences. Many evangelical books and websites are specialized on the subject.


title: Human sexuality

text: The perceptions of homosexuality in the Evangelical Churches are varied. They range from liberal through moderate to conservative.


title: Human sexuality

text: In Islam, desire for sex is considered to be a natural urge that should not be suppressed, although the concept of free sex is not accepted; these urges should be fulfilled responsibly. Marriage is considered to be a good deed; it does not hinder spiritual wayfaring. The term used for marriage within the Quran is . Although Islamic sexuality is restrained via Islamic sexual jurisprudence, it emphasizes sexual pleasure within marriage. It is acceptable for a man to have more than one wife, but he must take care of those wives physically, mentally, emotionally, financially, and spiritually. Muslims believe that sexual intercourse is an act of worship that fulfils emotional and physical needs, and that producing children is one way in which humans can contribute to God's creation, and Islam discourages celibacy once an individual is married.


title: Human sexuality

text: However, homosexuality is strictly forbidden in Islam, and some Muslim lawyers have suggested that gay people should be put to death. On the other hand, some have argued that Islam has an open and playful approach to sex so long as it is within marriage, free of lewdness, fornication and adultery.


title: Human sexuality

text: Hinduism emphasizes that sex is only appropriate between husband and wife, in which satisfying sexual urges through sexual pleasure is an important duty of marriage. Any sex before marriage is considered to interfere with intellectual development, especially between birth and the age of 25, which is said to be brahmacharya and this should be avoided. Kama (sensual pleasures) is one of the four purusharthas or aims of life (dharma, artha, kama, and moksha). The Hindu "Kama Sutra" deals partially with sexual intercourse; it is not exclusively a sexual or religious work.


title: Human sexuality

text: Sikhism views chastity as important, as Sikhs believe that the divine spark of "Waheguru" is present inside every individual's body, therefore it is important for one to keep clean and pure. Sexual activity is limited to married couples, and extramarital sex is forbidden. Marriage is seen as a commitment to "Waheguru" and should be viewed as part of spiritual companionship, rather than just sexual intercourse, and monogamy is deeply emphasised in Sikhism. Any other way of living is discouraged, including celibacy and homosexuality. However, in comparison to other religions, the issue of sexuality in Sikhism is not considered one of paramount importance.


title: Planet

text: A planet is a large, rounded astronomical body that is neither a star nor its remnant. The best available theory of planet formation is the nebular hypothesis, which posits that an interstellar cloud collapses out of 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 Solar System has at least eight planets: the terrestrial planets Mercury, Venus, Earth and Mars, and the giant planets Jupiter, Saturn, Uranus and Neptune. These planets each rotate around an axis tilted with respect to its orbital pole. All of them possess an atmosphere, although that of Mercury is tenuous, and some share such features as ice caps, seasons, volcanism, hurricanes, tectonics, and even hydrology. Apart from Venus and Mars, the Solar System planets generate magnetic fields, and all except Venus and Mercury have natural satellites. The giant planets bear planetary rings, the most prominent being those of Saturn.


title: Planet

text: The word "planet" probably comes from the Greek "planḗtai," meaning "wanderers". In antiquity, this word referred to the Sun, Moon, and five points of light visible by 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 was recognized as a planet when heliocentrism supplanted geocentrism during the 16th and 17th centuries.


title: Planet

text: With the development of the telescope, the meaning of "planet" broadened to include objects only visible with assistance: 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 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. The International Astronomical Union (IAU) adopted a standard by which the four terrestrials and four giants qualify, placing Ceres, Pluto and Eris in the category of dwarf planet, although many planetary scientists have continued to apply the term "planet" more broadly.


title: Planet

text: Further advances in astronomy led to the discovery of over five thousand planets outside the Solar System, termed exoplanets. These include hot Jupiters—giant planets that orbit close to their parent stars—like 51 Pegasi b, super-Earths like Gliese 581c that have masses in between that of Earth and Neptune; and planets smaller than Earth, like Kepler-20e. Multiple exoplanets have been found to orbit in the habitable zones of their stars, but Earth remains the only planet known to support life.


title: Planet

text: The idea of planets has evolved over its history, from the divine lights of antiquity to the earthly objects of the scientific age. The concept has expanded to include worlds not only in the Solar System, but in multitudes of other extrasolar systems. The consensus definition as to what counts as a planet vs. other objects orbiting the Sun has changed several times, previously encompassing asteroids, moons, and dwarf planets like Pluto, and there continues to be some disagreement today.


title: Planet

text: The five classical planets of the Solar System, being visible to the naked eye, have been known since ancient times and have had 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 (, "wandering stars") or simply (, "wanderers"), from which today's word "planet" 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 was not moving but at rest.


title: Planet

text: 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 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 a list of omens and their relationships with various celestial phenomena including the motions of the planets. Venus, Mercury, and the outer 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.


title: Planet

text: The ancient Greeks initially did not attach as much significance to the planets as the Babylonians. The Pythagoreans, in the 6th and 5th centuries BC 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 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.


title: Planet

text: By the 1st century BC, during the Hellenistic period, the Greeks had begun to develop their own mathematical schemes for predicting 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 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): the Moon, Mercury, Venus, the Sun, Mars, Jupiter, and Saturn.


title: Planet

text: 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 the stars. He also theorised that the orbits of planets were elliptical. Aryabhata's followers were particularly strong in South India, where his principles of the diurnal rotation of Earth, among others, were followed and a number of secondary works were based on them.


title: Planet

text: The astronomy of the Islamic Golden Age mostly took place in the Middle East, Central Asia, Al-Andalus, and North Africa, and later in the Far East and India. These astronomers, like the polymath Ibn al-Haytham, generally accepted geocentrism, although they did dispute Ptolemy's system of epicycles and sought alternatives. The 10th-century astronomer Abu Sa'id al-Sijzi accepted that the Earth rotates around its axis. In the 11th century, the transit of Venus was observed by Avicenna. His contemporary Al-Biruni devised a method of determining the Earth's radius using trigonometry that, unlike the older method of Eratosthenes, only required observations at a single mountain.


title: Planet

text: With the advent of the Scientific Revolution and the heliocentric model of Copernicus, Galileo and Kepler, use of the term "planet" changed from something that moved around the sky relative to the fixed star to a body that orbited the Sun, directly (a primary planet) or indirectly (a secondary or satellite planet). Thus the Earth was added to the roster of planets and the Sun was removed. The Copernican count of primary planets stood until 1781, when William Herschel discovered Uranus.


title: Planet

text: When four satellites of Jupiter (the Galilean moons) and five of Saturn were discovered in the 17th century, they were thought of as "satellite planets" or "secondary planets" orbiting the primary planets, though in the following decades they would come to be called simply "satellites" for short. Scientists generally considered planetary satellites to also be planets until about the 1920s, although this usage was not common among non-scientists.


title: Planet

text: In the first decade of the 19th century, four new planets were discovered: Ceres (in 1801), Pallas (in 1802), Juno (in 1804), and Vesta (in 1807). It soon became apparent that they were rather different from previously known planets: they shared the same general region of space, between Mars and Jupiter (the asteroid belt), with sometimes overlapping orbits. This was an area where only one planet had been expected, and they were much much smaller than all other planets; indeed, it was suspected that they might be shards of a larger planet that had broken up. Herschel called them "asteroids" (from the Greek for "starlike") because even in the largest telescopes they resembled stars, without a resolvable disk.


title: Planet

text: The situation was stable for four decades, but in the mid-1840s several additional asteroids were discovered (Astraea in 1845, Hebe in 1847, Iris in 1847, Flora in 1848, Metis in 1848, and Hygiea in 1849), and soon new "planets" were discovered every year. As a result, astronomers began tabulating the asteroids (minor planets) separately from the major planets, and assigning them numbers instead of abstract planetary symbols, although they continued to be considered as small planets.


title: Planet

text: Neptune was discovered in 1846, its position having been predicted thanks to its gravitational influence upon Uranus. Because the orbit of Mercury appeared to be affected in a similar way, it was believed in the late 19th century that there might be another planet even closer to the Sun. However, the discrepancy between Mercury's orbit and the predictions of Newtonian gravity was instead explained by an improved theory of gravity, Einstein's general relativity.


title: Planet

text: Pluto was discovered in 1930. After initial observations led to the belief that it was larger than Earth, the object was immediately accepted as the ninth major planet. Further monitoring found the body was actually much smaller: in 1936, Ray Lyttleton suggested that Pluto may be an escaped satellite of Neptune, and Fred Whipple suggested in 1964 that Pluto may be a comet. The discovery of its large moon Charon in 1978 showed that Pluto was only 0.2% the mass of Earth. As this was still substantially more massive than any known asteroid, and because no other trans-Neptunian objects had been discovered at that time, Pluto kept its planetary status, only officially losing it in 2006.


title: Planet

text: In the 1950s, Gerard Kuiper published papers on the origin of the asteroids. He recognised that asteroids were typically not spherical, as had previously been thought, and that the asteroid families were remnants of collisions. Thus he differentiated between the largest asteroids as "true planets" versus the smaller ones as collisional fragments. From the 1960s onwards, the term "minor planet" was mostly displaced by the term "asteroid", and references to the asteroids as planets in the literature became scarce, except for the geologically evolved largest three: Ceres, and less often Pallas and Vesta.


title: Planet

text: The beginning of Solar System exploration by space probes in the 1960s spurred a renewed interest in planetary science. A split in definitions regarding satellites occurred around then: planetary scientists began to reconsider the large moons as also being planets, but astronomers who were not planetary scientists generally did not.


title: Planet

text: In 1992, astronomers Aleksander Wolszczan and Dale Frail announced the discovery of planets around a pulsar, PSR B1257+12. This discovery is generally considered to be the first definitive detection of a planetary system around another star. Then, on 6 October 1995, Michel Mayor and Didier Queloz of the Geneva Observatory announced the first definitive detection of an exoplanet orbiting an ordinary main-sequence star (51 Pegasi).


title: Planet

text: The discovery of extrasolar planets led to another ambiguity in defining a planet: the point at which a planet becomes a star. Many known extrasolar planets are many times the mass of Jupiter, approaching that of stellar objects known as brown dwarfs. Brown dwarfs are generally considered stars due to their theoretical ability to fuse deuterium, a heavier isotope of hydrogen. Although objects more massive than 75 times that of Jupiter fuse simple hydrogen, objects of 13 Jupiter masses can fuse deuterium. Deuterium is quite rare, constituting less than 0.0026% of the hydrogen in the galaxy, and most brown dwarfs would have ceased fusing deuterium long before their discovery, making them effectively indistinguishable from supermassive planets.


title: Planet

text: With the discovery during the latter half of the 20th century of more objects within the Solar System and large objects around other stars, disputes arose over what should constitute a planet. There were particular disagreements over whether an object should be considered a planet if it was part of a distinct population such as a belt, or if it was large enough to generate energy by the thermonuclear fusion of deuterium. Complicating the matter even further, bodies too small to generate energy by fusing deuterium can form by gas-cloud collapse just like stars and brown dwarfs, even down to the mass of Jupiter: there was thus disagreement about whether how a body formed should be taken into account.


title: Planet

text: A growing number of astronomers argued for Pluto to be declassified as a planet, because many similar objects approaching its size had been found in the same region of the Solar System (the Kuiper belt) during the 1990s and early 2000s. Pluto was found to be just one small body in a population of thousands. They often referred to the demotion of the asteroids as a precedent, although that had been done based on their geophysical differences from planets rather than their being in a belt. Some of the larger trans-Neptunian objects, such as Quaoar, Sedna, Eris, and Haumea were heralded in the popular press as the tenth planet. The announcement of Eris in 2005, an object 27% more massive than Pluto, created the impetus for an official definition of a planet, as considering Pluto a planet would logically have demanded that Eris be considered a planet as well. Since different procedures were in place for naming planets versus non-planets, this created an urgent situation because under the rules Eris could not be named without defining what a planet was. At the time, it was also thought that the size required for a trans-Neptunian object to become round was about the same as that required for the moons of the giant planets (about 400 km diameter), a figure that would have suggested about 200 round objects in the Kuiper belt and thousands more beyond. Many astronomers argued that the public would not accept a definition creating a large number of planets.


title: Planet

text: To acknowledge the problem, the IAU set about creating the definition of planet, and produced one in August 2006. Their definition dropped to the eight significantly larger bodies that had cleared their orbit (Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune), and a new class of dwarf planets was created, initially containing three objects (Ceres, Pluto and Eris).


title: Planet

text: This definition has not been universally used or accepted. In planetary geology celestial objects have been assessed and defined as planets by geophysical characteristics. Planetary scientists are more interested in planetary geology than dynamics, so they classify planets based on their geological properties. A celestial body may acquire a dynamic (planetary) geology at approximately the mass required for its mantle to become plastic under its own weight. This leads to a state of hydrostatic equilibrium where the body acquires a stable, round shape, which is adopted as the hallmark of planethood by geophysical definitions. For example:


title: Planet

text: In the Solar System, this mass is generally less than the mass required for a body to clear its orbit, and thus some objects that are considered "planets" under geophysical definitions are not considered as such under the IAU definition, such as Ceres and Pluto. Proponents of such definitions often argue that location should not matter and that planethood should be defined by the intrinsic properties of an object.


title: Planet

text: Dwarf planets had been proposed as a category of small planet (as opposed to planetoids as sub-planetary objects) and planetary geologists continue to treat them as planets despite the IAU definition.


title: Planet

text: The number of dwarf planets even among known objects is not certain. In 2019, Grundy et al. argued based on the low densities of some mid-sized trans-Neptunian objects that the limiting size required for a trans-Neptunian object to reach equilibrium was in fact much larger than it is for the icy moons of the giant planets, being about 900 km diameter. There is general consensus on Ceres in the asteroid belt and on the eight trans-Neptunians that probably cross this threshold: Quaoar, Sedna, Orcus, Pluto, Haumea, Eris, Makemake, and Gonggong. Planetary geologists may include the twenty known planetary-mass moons as "satellite planets", including Earth's Moon and Pluto's Charon, like the early modern astronomers. Some go even further and include relatively large, geologically evolved bodies that are nonetheless not very round today, such as Pallas and Vesta, or rounded bodies that were completely disrupted by impacts and re-accreted like Hygiea, as planets.


title: Planet

text: The 2006 IAU definition presents some challenges for exoplanets because the language is specific to the Solar System and the criteria of roundness and orbital zone clearance are not presently observable for exoplanets. There is no official definition of exoplanets, but the IAU's working group on the topic adopted a provisional statement in 2018.


title: Planet

text: Astronomer Jean-Luc Margot proposed a mathematical criterion that determines whether an object can clear its orbit during the lifetime of its host star, based on the mass of the planet, its semimajor axis, and the mass of its host star. The formula produces a value called that is greater than 1 for planets. The eight known planets and all known exoplanets have values above 100, while Ceres, Pluto, and Eris have values of 0.1, or less. Objects with values of 1 or more are expected to be approximately spherical, so that objects that fulfill the orbital zone clearance requirement automatically fulfill the roundness requirement.


title: Planet

text: the following definition was passed in a resolution voted for by a large majority of those remaining at the meeting, addressing particularly the issue of the lower limits for a celestial object to be defined as a planet. The 2006 resolution defines planets within the Solar System as follows:


title: Planet

text: Under this definition, the Solar System is considered to have eight planets. Bodies that fulfill the first two conditions but not the third are classified as dwarf planets, provided they are not natural satellites of other planets. Originally an IAU committee had proposed a definition that would have included a larger number of planets as it did not include (c) as a criterion. After much discussion, it was decided via a vote that those bodies should instead be classified as dwarf planets.


title: Planet

text: This definition is based in modern theories of planetary formation, in which planetary embryos initially clear their orbital neighborhood of other smaller objects. As described below, planets form by material accreting together in a disk of matter surrounding a protostar. This process results in a collection of relatively substantial objects, each of which has either "swept up" or scattered away most of the material that had been orbiting near it. These objects do not collide with one another because they are too far apart, sometimes in orbital resonance.


title: Planet

text: The 2006 IAU definition presents some challenges for exoplanets because the language is specific to the Solar System and the criteria of roundness and orbital zone clearance are not presently observable for exoplanets. The IAU working group on extrasolar planets (WGESP) issued a working definition in 2001 and amended it in 2003. In 2018, this definition was reassessed and updated as knowledge of exoplanets increased. The current official working definition of an exoplanet is as follows:


title: Planet

text: The IAU noted that this definition could be expected to evolve as knowledge improves. A 2022 review article discussing the history and rationale of this definition suggested that the words "in young star clusters" should be deleted in clause 3, as such objects have now been found elsewhere, and that the term "sub-brown dwarfs" should be replaced by the more current "free-floating planetary mass objects".


title: Planet

text: Geoscientists often reject the IAU definition, preferring to consider round moons and dwarf planets as also being planets. Some scientists who accept the IAU definition of "planet" use other terms for bodies satisfying geophysical planet definitions, such as "world". The term "planetary mass object" has also been used to refer to ambiguous situations concerning exoplanets, such as objects with mass typical for a planet that are free-floating or orbit a brown dwarf instead of a star.


title: Planet

text: The names for the planets in the Western world are derived from the naming practices of the Romans, which ultimately derive from those of the Greeks and the Babylonians. In ancient Greece, the two great luminaries the Sun and the Moon were called "Helios" and "Selene", two ancient Titanic deities; the slowest planet (Saturn) was called "Phainon", the shiner; followed by "Phaethon" (Jupiter), "bright"; the red planet (Mars) was known as "Pyroeis", the "fiery"; the brightest (Venus) was known as "Phosphoros", the light bringer; and the fleeting final planet (Mercury) was called "Stilbon", the gleamer. The Greeks assigned each planet to one among their pantheon of gods, the Olympians and the earlier Titans:


title: Planet

text: The Greek practice of grafting their gods' names onto the planets was almost certainly borrowed from the Babylonians. The Babylonians named Venus after their goddess of love, Ishtar; Mars after their god of war, Nergal; Mercury after their god of wisdom Nabu; and Jupiter after their chief god, Marduk. There are too many concordances between Greek and Babylonian naming conventions for them to have arisen separately. Given the differences in mythology, the correspondence was not perfect. For instance, the Babylonian Nergal was a god of war, and thus the Greeks identified him with Ares. Unlike Ares, Nergal was also a god of pestilence and ruler of the underworld.


title: Planet

text: Today, most people in the western world know the planets by names derived from the Olympian pantheon of gods. Although modern Greeks still use their ancient names for the planets, other European languages, because of the influence of the Roman Empire and, later, the Catholic Church, use the Roman (Latin) names rather than the Greek ones. The Romans inherited Proto-Indo-European mythology as the Greeks did and shared with them a common pantheon under different names, but the Romans lacked the rich narrative traditions that Greek poetic culture had given their gods. During the later period of the Roman Republic, Roman writers borrowed much of the Greek narratives and applied them to their own pantheon, to the point where they became virtually indistinguishable. When the Romans studied Greek astronomy, they gave the planets their own gods' names: "Mercurius" (for Hermes), "Venus" (Aphrodite), "Mars" (Ares), "Iuppiter" (Zeus) and "Saturnus" (Cronus). Some Romans, following a belief possibly originating in Mesopotamia but developed in Hellenistic Egypt, believed that the seven gods after whom the planets were named took hourly shifts in looking after affairs on Earth. The order of shifts went Saturn, Jupiter, Mars, Sun, Venus, Mercury, Moon (from the farthest to the closest planet). Therefore, the first day was started by Saturn (1st hour), second day by Sun (25th hour), followed by Moon (49th hour), Mars, Mercury, Jupiter and Venus. Because each day was named by the god that started it, this became the order of the days of the week in the Roman calendar. In English, "Saturday", "Sunday", and "Monday" are straightforward translations of these Roman names. The other days were renamed after "Tīw" (Tuesday), "Wōden" (Wednesday), "Þunor" (Thursday), and "Frīġ" (Friday), the Anglo-Saxon gods considered similar or equivalent to Mars, Mercury, Jupiter, and Venus, respectively.


title: Planet

text: Earth's name in English is not derived from Greco-Roman mythology. Because it was only generally accepted as a planet in the 17th century, there is no tradition of naming it after a god. (The same is true, in English at least, of the Sun and the Moon, though they are no longer generally considered planets.) The name originates from the Old English word "eorþe", which was the word for "ground" and "dirt" as well as the world itself. As with its equivalents in the other Germanic languages, it derives ultimately from the Proto-Germanic word "erþō", as can be seen in the English "earth", the German "Erde", the Dutch "aarde", and the Scandinavian "jord". Many of the Romance languages retain the old Roman word "terra" (or some variation of it) that was used with the meaning of "dry land" as opposed to "sea". The non-Romance languages use their own native words. The Greeks retain their original name, "Γή" "(Ge)".


title: Planet

text: Non-European cultures use other planetary-naming systems. India uses a system based on the Navagraha, which incorporates the seven traditional planets ("Surya" 'Sun', "Chandra" 'Moon', "Budha" for Mercury, "Shukra" ('bright') for Venus, "Mangala" (the god of war) for Mars, "" (councilor of the gods) for Jupiter, and "Shani" (symbolic of time) for Saturn) and the ascending and descending lunar nodes "Rahu" and "Ketu".


title: Planet

text: China and the countries of eastern Asia historically subject to Chinese cultural influence (such as Japan, Korea and Vietnam) use a naming system based on the five Chinese elements: water (Mercury 水星 "water star"), metal (Venus 金星 "metal star"), fire (Mars 火星 "fire star"), wood (Jupiter 木星 "wood star") and earth (Saturn 土星 "earth star"). The names of Uranus (天王星 "sky king star"), Neptune (海王星 "sea king star"), and Pluto (冥王星 "underworld king star") in Chinese, Korean, and Japanese are calques based on the roles of those gods in Roman and Greek mythology. Chinese uses calques for the dwarf planets and many asteroids as well, e.g. Eris (鬩神星 "quarrel goddess star"), Ceres (穀神星 "grain goddess star"), and Pallas (智神星 "wisdom goddess star").


title: Planet

text: In traditional Hebrew astronomy, the seven traditional planets have (for the most part) descriptive names – the Sun is חמה "Ḥammah" or "the hot one", the Moon is לבנה "Levanah" or "the white one", Venus is כוכב נוגה "Kokhav Nogah" or "the bright planet", Mercury is כוכב "Kokhav" or "the planet" (given its lack of distinguishing features), Mars is מאדים "Ma'adim" or "the red one", and Saturn is שבתאי "Shabbatai" or "the resting one" (in reference to its slow movement compared to the other visible planets). The odd one out is Jupiter, called צדק "Tzedeq" or "justice". Hebrew names were chosen for Uranus (אורון "Oron", "small light") and Neptune (רהב "Rahab", a Biblical sea monster) in 2009; prior to that the names "Uranus" and "Neptune" had simply been borrowed. The etymologies for the Arabic names of the planets are less well understood. Mostly agreed among scholars are Venus الزهرة ("az-Zuhara", "the bright one"), Earth الأرض ("al-ʾArḍ", from the same root as eretz), and Saturn زُحَل ("Zuḥal", "withdrawer"). Multiple suggested etymologies exist for Mercury عُطَارِد ("ʿUṭārid"), Mars اَلْمِرِّيخ ("al-Mirrīkh"), and Jupiter المشتري ("al-Muštarī"), but there is no agreement among scholars.


title: Planet

text: When subsequent planets were discovered in the 18th and 19th centuries, Uranus was named for a Greek deity and Neptune for a Roman one (the counterpart of Poseidon). The asteroids were initially named from mythology as well – Ceres, Juno, and Vesta are major Roman goddesses, and Pallas is an epithet of the Greek goddess Athena – but as more and more were discovered, the mythological restriction was dropped starting from Massalia in 1852. Pluto was given a classical name, as it was considered a major planet when it was discovered. After more objects were discovered beyond Neptune, naming conventions depending on their orbits were put in place: those in the 2:3 resonance with Neptune (the plutinos) are given names from underworld myths, while others are given names from creation myths. Most of the trans-Neptunian dwarf planets are named after gods and goddesses from other cultures (e.g. Quaoar is named after a Tongva god), except for Orcus and Eris which continued the Roman and Greek scheme.


title: Planet

text: The moons (including the planetary-mass ones) are generally given names with some association with their parent planet. The planetary-mass moons of Jupiter are named after four of Zeus' lovers (or other sexual partners); those of Saturn are named after Cronus' brothers and sisters, the Titans; those of Uranus are named after characters from Shakespeare and Pope (originally specifically from fairy mythology, but that ended with the naming of Miranda). Neptune's planetary-mass moon Triton is named after the god's son; Pluto's planetary-mass moon Charon is named after the ferryman of the dead, who carries the souls of the newly deceased to the underworld (Pluto's domain); and Eris' only known moon Dysnomia is named after one of Eris' daughters, the spirit of lawlessness.


title: Planet

text: The written symbols for Mercury, Venus, Jupiter, Saturn and possibly Mars have been traced to forms found in late Greek papyrus texts. The symbols for Jupiter and Saturn are identified as monograms of the corresponding Greek names, and the symbol for Mercury is a stylized caduceus.


title: Planet

text: According to Annie Scott Dill Maunder, antecedents of the planetary symbols were used in art to represent the gods associated with the classical planets. "Bianchini's planisphere", discovered by Francesco Bianchini in the 18th century but produced in the 2nd century, shows Greek personifications of planetary gods charged with early versions of the planetary symbols. Mercury has a caduceus; Venus has, attached to her necklace, a cord connected to another necklace; Mars, a spear; Jupiter, a staff; Saturn, a scythe; the Sun, a circlet with rays radiating from it; and the Moon, a headdress with a crescent attached. The modern shapes with the cross-marks first appeared around the 16th century. According to Maunder, the addition of crosses appears to be "an attempt to give a savour of Christianity to the symbols of the old pagan gods." Earth itself was not considered a classical planet; its symbol descends from a pre-heliocentric symbol for the four corners of the world.


title: Planet

text: When further planets were discovered orbiting the Sun, symbols were invented for them. The most common astronomical symbol for Uranus, ⛢, was invented by Johann Gottfried Köhler, and was intended to represent the newly discovered metal platinum. An alternative symbol, ♅, was invented by Jérôme Lalande, and represents a globe with a H on top, for Uranus' discoverer Herschel. Today, ⛢ is mostly used by astronomers and ♅ by astrologers, though it is possible to find each symbol in the other context. The first few asteroids were similarly given abstract symbols, but as their number rose further and further, this practice stopped in favour of numbering them instead. Neptune's symbol (♆) represents the god's trident. The astronomical symbol for Pluto is a P-L monogram (♇),<ref name="JPL/NASA Pluto's Symbol">


title: Planet

text: </ref> though it has become less common since the IAU definition reclassified Pluto. Since Pluto's reclassification, NASA has used the traditional astrological symbol of Pluto (⯓), a planetary orb over Pluto's bident.


title: Planet

text: The IAU discourages the use of planetary symbols in modern journal articles in favour of one-letter or (to disambiguate Mercury and Mars) two-letter abbreviations for the major planets. The symbols for the Sun and Earth are nonetheless common, as solar mass, Earth mass and similar units are common in astronomy. Other planetary symbols today are mostly encountered in astrology. Astrologers have started reusing the old astronomical symbols for the first few asteroids, and continue to invent symbols for other objects, though most proposed symbols are only used by their proposers. Unicode includes some relatively standard astrological symbols for some minor planets, including the dwarf planets discovered in the 21st century, though astronomical use of any of them is rare.


title: Planet

text: It is not known with certainty how planets are built. The prevailing theory is that they are formed during 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 a planet reaches a mass somewhat larger than Mars' 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 a similar way; however, Triton was likely captured by Neptune, and Earth's Moon and Pluto's Charon might have formed in collisions.


title: Planet

text: 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 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.


title: Planet

text: The energetic impacts of 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 the subsequent impact of comets. (Smaller planets will lose any atmosphere they gain through various escape mechanisms.)


title: Planet

text: 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 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.


title: Planet

text: 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 is the smallest, at 0.055 Earth masses.


title: Planet

text: 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 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 a significantly lower mass than the gas giants (only 14 and 17 Earth masses).


title: Planet

text: 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 , , , , , , , and . Ceres is the largest object in 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 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 the most massive known.


title: Planet

text: There are at least twenty planetary-mass moons or satellite planets—moons large enough to take on ellipsoidal shapes (though Dysnomia's shape has never been measured, it is massive and dense enough to be a solid body). The twenty generally agreed are as follows.


title: Planet

text: 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 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. ).


title: Planet

text: The tables below summarise some properties of objects generally agreed to satisfy geophysical planet definitions. There are many smaller dwarf planet candidates, such as Salacia, that have not been included in the tables because astronomers disagree on whether or not they are dwarf planets. The diameters, masses, orbital periods, and rotation periods of the major planets are available from the Jet Propulsion Laboratory. JPL also provides their semi-major axes, inclinations, and eccentricities of planetary orbits, and the axial tilts are taken from their Horizons database. Other information is summarized by NASA. The data for the dwarf planets and planetary-mass moons is taken from list of gravitationally rounded objects of the Solar System, with sources listed there.


title: Planet

text: As all the planetary-mass moons exhibit synchronous rotation, their rotation periods equal their orbital periods.


title: Planet

text: An exoplanet (extrasolar planet) is a planet outside the Solar System. Known exoplanets range in size from gas giants about twice as large as Jupiter down to just over 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.


title: Planet

text: 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 a disk remnant left over from the supernova that produced the pulsar.


title: Planet

text: The first confirmed discovery of an extrasolar planet 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 mission most known extrasolar planets 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 the size of Neptune and smaller, down to smaller than Mercury.


title: Planet

text: In 2011, the Kepler Space Telescope team reported the discovery of the first Earth-sized extrasolar planets 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 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 the number of intelligent, communicating civilizations that exist in the Milky Way.


title: Planet

text: 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. Such planets could be rocky like Earth or a mixture of volatiles and gas like Neptune—the dividing line between the two possibilities is currently thought to occur at about twice the mass of Earth. The planet Gliese 581c, with 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. Exoplanets have been found that are much closer to their parent star than any planet in 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 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.


title: Planet

text: 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 the Solar System, whereas others are commonly observed in extrasolar planets.


title: Planet

text: 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 extrasolar planet, 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; 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.


title: Planet

text: 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 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.


title: Planet

text: 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 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 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. Among extrasolar planets, axial tilts are not known for certain, though most hot Jupiters are believed to have a negligible axial tilt as a result of their proximity to their stars.


title: Planet

text: The planets rotate around invisible axes through their centres. A planet's rotation period 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 is used, Uranus has a retrograde rotation relative to its orbit.


title: Planet

text: 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 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 extrasolar planets 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, 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' rotation may be in equilibrium between tidal forces slowing it down and atmospheric tides created by solar heating speeding it up.


title: Planet

text: 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. The other dwarf planets with known rotation periods rotate faster than Earth; Haumea rotates so fast that it has been distorted into a triaxial ellipsoid. The exoplanet Tau Boötis b and its parent star Tau Boötis appear to be mutually tidally locked.


title: Planet

text: 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 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.


title: Planet

text: Gravity causes planets to be pulled into 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 is 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.


title: Planet

text: A planet's defining physical characteristic 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 the object collapses into a sphere.


title: Planet

text: Mass is the prime attribute by which planets are distinguished from stars. While the lower stellar mass limit is estimated to be around 75 times that of Jupiter (), the upper planetary mass limit for planethood is only roughly 13 for objects with solar-type isotopic abundance, beyond which it achieves conditions suitable for nuclear fusion of deuterium. Other than the Sun, no objects of such mass exist in the Solar System; but there are exoplanets of this size. The 13 limit is not universally agreed upon and the Extrasolar Planets Encyclopaedia includes objects up to 60 , and the Exoplanet Data Explorer up to 24 .


title: Planet

text: The smallest known exoplanet with an accurately known mass is PSR B1257+12A, one of the first extrasolar planets discovered, which 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 the Moon.


title: Planet

text: 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 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 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.


title: Planet

text: All of 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 the light gases hydrogen and helium, whereas the smaller planets lose these gases into space. The composition of Earth's atmosphere is different from the other planets because the various life processes that have transpired on the planet have introduced free molecular oxygen.


title: Planet

text: Planetary atmospheres are affected by the varying insolation or internal energy, leading to 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, the super-Earth Gliese 1214 b and others.


title: Planet

text: 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 the atmospheric dynamics that affect the day-night temperature difference are complex.


title: Planet

text: 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 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.


title: Planet

text: Of 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 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.


title: Planet

text: In 2003, a team of astronomers in Hawaii observing the star HD 179949 detected a bright spot on its surface, apparently created by the magnetosphere of an orbiting hot Jupiter.


title: Planet

text: 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 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).


title: Planet

text: 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 the origins of planetary rings is not precisely known, they are believed to be the result of natural satellites that fell below their parent planet's Roche limit and were torn apart by tidal forces. The dwarf planet Haumea also has a ring.


title: Planet

text: No secondary characteristics have been observed around extrasolar planets. The sub-brown dwarf Cha 110913-773444, which has been described as 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.


title: Creed (film)

text: Creed is a 2015 American sports drama film directed by Ryan Coogler from a screenplay by Coogler, Aaron Covington and contributions by Sylvester Stallone. It is the sequel to "Rocky Balboa" (2006), the seventh installment and spin-off of the "Rocky" franchise, and stars Michael B. Jordan, Stallone, Tessa Thompson, Phylicia Rashad, Tony Bellew, and Graham McTavish. In the film, amateur boxer Adonis Creed (Jordan) is trained and mentored by Rocky Balboa (Stallone), the former rival turned friend of Adonis' father, Apollo Creed.


title: Creed (film)

text: Although "Rocky Balboa" was considered the end of the franchise, Metro-Goldwyn-Mayer hired Coogler in 2013 to develop a "Rocky" spin-off. Coogler and Covington's original screenplay was completed by April 2014, with the involvement of Jordan and Stallone also confirmed. The remaining cast were hired by January 2015, after which, principal photography began and lasted until that April, with filming locations including Liverpool, Philadelphia, and Gainesville.


title: Creed (film)

text: "Creed" premiered on November 19, 2015, at the Regency Village Theater in Los Angeles, and was theatrically released in the United States on November 25, to coincide with the 40th anniversary of the date of the opening scene in the first film.


title: Creed (film)

text: The film was praised for Coogler's direction, the screenplay, and acting performances. The film was also a commercial success, grossing $173 million worldwide. Among its accolades, it was selected by National Board of Review as one of the top ten films of 2015, while Stallone won the National Board of Review Award for Best Supporting Actor, the Critics' Choice Award for Best Supporting Actor, and Golden Globe Award for Best Supporting Actor in a Motion Picture, and was nominated for the Academy Award for Best Supporting Actor. The sequel, "Creed II", was released in 2018. A third film, "Creed III", is set to be released on March 3, 2023.


title: Creed (film)

text: In 1998, Adonis "Donnie" Johnson -- the son of former heavyweight champion Apollo Creed via an extramarital affair -- is serving time in a Los Angeles youth detention center when Creed's widow, Mary Anne, visits and offers to take him in.


title: Creed (film)

text: In 2015, Donnie is in Tijuana, preparing for his fight in an amateur boxing bout hosted in a bar. Upon returning from his latest fight, Donnie resigns from the Smith Boardley Financial Group to pursue his dream of becoming a professional boxer. Donnie auditions at Los Angeles' elite Delphi Boxing Academy, managed by family friend Tony "Little Duke" Evers Jr., the son of Apollo's trainer Tony "Duke" Evers, but is turned down. This rejection is further emphasized as Donnie is beaten in a sparring match by light heavyweight division #2 contender Danny "The Stuntman" Wheeler after he publicly challenges the whole gym to prove himself, betting his 1967 Ford Mustang that no one can get a clean head shot on him. Mary Anne vehemently opposes his aspirations, remembering how her husband was killed in the ring by Ivan Drago thirty years ago. Undaunted, Donnie travels to Philadelphia in hopes of getting in touch with his father's old friend and rival, former heavyweight champion, Rocky Balboa.


title: Creed (film)

text: Donnie meets Rocky at Rocky's Italian restaurant, Adrian's, named in honor of his deceased wife, and asks Rocky to become his trainer. Rocky is reluctant to return to boxing, having already made a one-off comeback at a very advanced age despite having suffered brain trauma during his career as a fighter. However, he eventually agrees. Donnie asks him about the "secret third fight" between him and Apollo just after Apollo helped Rocky regain the heavyweight title, and Rocky reveals that Apollo won. Donnie trains at the Front Street Gym, with several of Rocky's longtime friends as cornermen. He also finds a love interest in Bianca, an up-and-coming singer and songwriter in the early stages of progressive hearing loss.


title: Creed (film)

text: Donnie, fighting under his biological mother's surname, Johnson, and the fight name "Hollywood", defeats local fighter Leo "The Lion" Sporino, which upsets the opposing corner. This leads to the opposing side leaking the news that Donnie is Creed's illegitimate son. Rocky receives a call from the handlers of world light heavyweight champion "Pretty" Ricky Conlan, who is being forced into retirement by an impending prison term. He offers to make Donnie his final challenger—provided that he legally change his surname to Creed. Donnie balks at first, wanting to forge his own legacy. However, he eventually agrees.


title: Creed (film)

text: While helping Donnie train, Rocky is diagnosed with non-Hodgkin's lymphoma. He is unwilling to undergo chemotherapy, remembering that it was not enough to save Adrian when she had ovarian cancer. His diagnosis and the fact that his best friend and brother-in-law Paulie Pennino—Adrian's brother—has now died on top of Adrian, Apollo, and his old trainer, Mickey Goldmill, further force him to confront his own mortality. Seeing Rocky shaken, Donnie urges him to seek treatment, which he does.


title: Creed (film)

text: Donnie fights Conlan at Goodison Park in Conlan's hometown of Liverpool, and many parallels emerge between the bout that ensues, and Apollo and Rocky's first fight forty years earlier. First, before entering the ring, Donnie receives a present from Mary Anne — new American flag trunks similar to the ones Apollo and later Rocky wore. Additionally, to the surprise of nearly everyone, Donnie gives Conlan all he can handle. Conlan knocks Donnie down, but Donnie recovers to knock Conlan down for the first time in his career. Donnie goes the distance, but Conlan wins on a split decision, and Donnie has won the respect of Conlan and the crowd. As Max Kellerman puts it while calling the fight for HBO, "Ricky Conlan won the fight, but Adonis Creed won the night." Conlan tells Donnie that he is the future of the light heavyweight division.


title: Creed (film)

text: The film ends with Donnie and a frail but improving Rocky climbing the 72 steps outside the entrance of the Philadelphia Museum of Art.


title: Creed (film)

text: Liev Schreiber voices an "HBO 24/7" announcer, while Michael Buffer cameos as himself serving as ring announcer. Other sports media personalities who appear include ESPN's Tony Kornheiser, Michael Wilbon, Hannah Storm, and Max Kellerman, and HBO Sports' boxing announcer Jim Lampley.


title: Creed (film)

text: On July 24, 2013, it was announced that Metro-Goldwyn-Mayer had signed on with "Fruitvale Station" director Ryan Coogler to direct a spin-off of "Rocky", a seventh film in the "Rocky" series, which Coogler would also co-write with Aaron Covington. Sylvester Stallone also worked on the screenplay for the seventh film. The film would focus on a man following in the footsteps of his late father, Apollo Creed, and getting a mentor in the now-retired Rocky Balboa. Michael B. Jordan was set for the role of Creed's son, Adonis "Donnie" Creed, and Stallone was set to reprise his character of Rocky. Original producers Irwin Winkler and Robert Chartoff would produce, along with Stallone and Kevin King-Templeton. On April 25, 2014, while talking to "THR", Coogler stated that he had sent his latest draft to the studio, and confirmed the involvement of Jordan and Stallone.


title: Creed (film)

text: On November 10, real-life boxers Tony Bellew and Andre Ward joined the film, with Bellew to play a fighter, "Pretty" Ricky Conlan, the main opponent for Creed. Shooting was set to begin in January 2015, in Las Vegas and Philadelphia. On December 16, Tessa Thompson was added to the cast as the female lead. On January 8, 2015, Phylicia Rashad reportedly joined the film to play Mary Anne Creed, Apollo's widow. Sylvia Meals, who portrayed Mrs. Creed in "Rocky II" and "Rocky IV" had died in 2011. On January 21, Graham McTavish tweeted about his involvement in the film.


title: Creed (film)

text: Principal photography began on January 19, 2015 on location at Goodison Park, with the first scene shot taking place during a Barclays Premier League football match between Everton (of which Stallone and native Evertonian Bellew are fans) and West Bromwich Albion. Goodison would later host both the climactic film fight between Donnie and Conlan and also Bellew's real-life title fight against Ilunga Makabu in May 2016, which was the first outdoor boxing match in Liverpool since 1949.


title: Creed (film)

text: Filming also took place in Philadelphia. In early February, an empty store in Philadelphia was converted into a boxing gym, where some training scenes were shot.


title: Creed (film)

text: On February 13, the crew was spotted filming in the Victor Cafe in South Philadelphia. The cafe was transformed into the "Adrian's Restaurant", and crew were again spotted filming there on February 16. Stallone and Jordan were also spotted on the set of the film on February 18. From February 24–27 and then on March 3, filming took place at Sun Center Studios in Aston Township.


title: Creed (film)

text: The musical score for "Creed" was written by Swedish composer Ludwig Göransson, who is only the third composer in the history of the "Rocky" series, following Bill Conti ("Rocky", "II", "III", "V", and "Balboa") and Vince DiCola ("Rocky IV"). "Creed" also features a soundtrack that consists mostly of music new to the series, including hip hop tracks by artists such as Future, Meek Mill, and White Dave. Both a score and a soundtrack album were released on November 20, 2015 by WaterTower Music and Atlantic Records, respectively. One tribute to Conti's original soundtrack is included – the track "You're a Creed" uses both "Gonna Fly Now" and "Going the Distance".


title: Creed (film)

text: On February 3, 2015, Warner Bros. slated the film to be released domestically on November 25, 2015. This date coincides with the 40th anniversary of the opening scene in the original film, where Rocky fights Spider Rico.


title: Creed (film)

text: On December 20, 2015, screeners of numerous prospective awards contenders, including "Creed", were uploaded to torrent sites. The FBI has linked the case to co-CEO Andrew Kosove of Alcon Entertainment. Kosove claimed that he had "never seen this DVD", and that "it never touched his hands".


title: Creed (film)

text: "Creed" grossed $109.8 million in North America and $63.8 million in other territories for a worldwide total of $173.6 million, against a budget of $35 million. In North America, "Creed" opened on Wednesday, November 25, 2015, alongside "The Good Dinosaur" and "Victor Frankenstein", as well as the expanding wide releases of "Brooklyn", "Spotlight" and "Trumbo". The film ended up grossing $42.6 million in its first five days, including $30.1 million in its opening weekend, finishing third at the box office.


title: Creed (film)

text: The "Los Angeles Times" reported that the film received "early critical raves". On review aggregator website Rotten Tomatoes, the film holds an approval rating of 95% based on 312 reviews, with an average rating of 7.90/10. The website's critical consensus reads, ""Creed" brings the "Rocky" franchise off the mat for a surprisingly effective seventh round that extends the boxer's saga in interesting new directions while staying true to its classic predecessors' roots." On Metacritic, the film has a weighted average score of 82 out of 100, based on 42 critics, indicating "universal acclaim". Audiences polled by CinemaScore gave the film an average grade of "A" on an A+ to F scale, while PostTrak reported filmgoers gave it an overall positive score of 85%.


title: Creed (film)

text: "A.V. Wire"s Herman Dhaliwal gave the film a very positive review, writing, "I will say the film was everything I could have ever wanted and then some. It's a film that could have gone so wrong in so many ways so easily, but the results show something that is genuine and inspired. It takes the smartest possible routes with the story it wants to tell and delivers in basically every way it needed to. Ryan Coogler cements himself as one of the best rising filmmakers working today, as he crafts an emotional, funny, compelling and uplifting film that is full of strong performances." Andrew Barker of "Variety" stated that the film lives up to the expectation of its predecessors, while forging its own unique path. He also appreciated the performances of Stallone and Jordan, saying that Stallone deserved credit for taking a chance on young director Coogler, and that his trust had paid off. He concluded that the director "offered a smart, kinetic, exhilaratingly well-crafted piece of mainstream filmmaking". IGN reviewer John Lasser gave the film an 8.5 out of 10, saying, ""Creed" is a mirror of Rocky's story and we have all been watching that unfold on the big screen for decades. Coogler's film does nothing to break the mold. Rather, it shows that the mold exists for a reason. Jordan delivers a knockout performance, and Stallone does as well. In the end, we can all only hope that we'll get to see Adonis on screen for just as long as we've seen Rocky."


title: Creed (film)

text: The screenplay was ranked the 22nd best American screenplay of the 21st century in IndieWire, with Zack Sharf writing, "Not only does the script manage to tell an authentic origin story of the young and determined Adonis Creed, but it also finds an authentic way to revive Sylvester Stallone's Rocky and make him the emotional lynchpin of Adonis' rise to champion boxer."


title: Creed (film)

text: In January 2016, Sylvester Stallone and MGM CEO Gary Barber confirmed that a sequel to "Creed" was in development. That same month, Stallone posed the possibility of seeing Milo Ventimiglia appear in the sequel, reprising his role as Rocky's son Robert Balboa from "Rocky Balboa". Ventimiglia previously revealed during the development of "Creed" that he was open to returning to the franchise, stating, "I'll tell you what, if they invited me, I'd love to be there. If they didn't, I wouldn't be offended."


title: Creed (film)

text: Also that month, it was reported that the sequel's release was tentatively set for November 2017, although it was later pushed back to an unconfirmed date. Development was seemingly delayed by the announcement Coogler had cast Michael B. Jordan in his next film, Marvel's "Black Panther", thus delaying production until both men's schedules permitted.


title: Creed (film)

text: A confrontation between Adonis "Donnie" Creed and Ivan Drago was hinted at on Instagram. Stallone later confirmed that he had finished writing the script for the sequel, which would see Dolph Lundgren reprising his role as Ivan Drago from "Rocky IV". By October 2017, Stallone stated on his social media page that he would direct the film, however, by December of the same year, Steven Caple Jr. was announced as the director of "Creed II". Boxer Florian Munteanu was cast as Drago's son. In an interview on "The Ellen DeGeneres Show", Jordan confirmed that "Creed II" was his next project.


title: Creed (film)

text: A sequel, "Creed III", directed by Jordan in his directorial debut, is scheduled to be released on March 3, 2023.


title: Donald Rumsfeld

text: Donald Henry Rumsfeld (July 9, 1932 – June 29, 2021) was an American politician, government official and businessman who served as Secretary of Defense from 1975 to 1977 under president Gerald Ford, and again from 2001 to 2006 under President George W. Bush. He was both the youngest and the oldest secretary of defense. Additionally, Rumsfeld was a three-term U.S. Congressman from Illinois (1963–1969), director of the Office of Economic Opportunity (1969–1970), counselor to the president (1969–1973), the U.S. Representative to NATO (1973–1974), and the White House Chief of Staff (1974–1975). Between his terms as secretary of defense, he served as the CEO and chairman of several companies.


title: Donald Rumsfeld

text: Born in Illinois, Rumsfeld attended Princeton University, graduating in 1954 with a degree in political science. After serving in the Navy for three years, he mounted a campaign for Congress in Illinois's 13th Congressional District, winning in 1962 at the age of 30. Rumsfeld accepted an appointment by President Richard Nixon to head the Office of Economic Opportunity in 1969; appointed counsellor by Nixon and entitled to Cabinet-level status, he also headed up the Economic Stabilization Program before being appointed ambassador to NATO. Called back to Washington in August 1974, Rumsfeld was appointed chief of staff by President Ford. Rumsfeld recruited a young one-time staffer of his, Dick Cheney, to succeed him when Ford nominated him to be Secretary of Defense in 1975. When Ford lost the 1976 election, Rumsfeld returned to private business and financial life, and was named president and CEO of the pharmaceutical corporation G. D. Searle & Company. He was later named CEO of General Instrument from 1990 to 1993 and chairman of Gilead Sciences from 1997 to 2001.


title: Donald Rumsfeld

text: Rumsfeld was appointed Secretary of Defense for a second time in January 2001 by President George W. Bush. As Secretary of Defense, Rumsfeld played a central role in the invasion of Afghanistan and invasion of Iraq. Before and during the Iraq War, he claimed that Iraq had an active weapons of mass destruction program; yet no stockpiles were ever found. A Pentagon Inspector General report found that Rumsfeld's top policy aide "developed, produced, and then disseminated alternative intelligence assessments on the Iraq and al-Qaeda relationship, which included some conclusions that were inconsistent with the consensus of the Intelligence Community, to senior decision-makers". Rumsfeld's tenure was controversial for its use of torture and the Abu Ghraib torture and prisoner abuse scandal. Rumsfeld gradually lost political support and resigned in late 2006. In his retirement years, he published an autobiography, "", as well as "Rumsfeld's Rules: Leadership Lessons in Business, Politics, War, and Life".


title: Donald Rumsfeld

text: Donald Henry Rumsfeld was born on July 9, 1932, in Chicago, Illinois, the son of Jeannette Kearsley (née Husted) and George Donald Rumsfeld. His father came from a German family that had emigrated in the 1870s from Weyhe in Lower Saxony, but young Donald was sometimes ribbed about looking like a "tough Swiss." Growing up in Winnetka, Illinois, Rumsfeld became an Eagle Scout in 1949 and is the recipient of both the Distinguished Eagle Scout Award from the Boy Scouts of America and its Silver Buffalo Award in 2006. Living in Winnetka, his family attended a Congregational church. From 1943 to 1945, Rumsfeld lived in Coronado, California, while his father was stationed on an aircraft carrier in the Pacific in World War II. He was a ranger at Philmont Scout Ranch in 1949.


title: Donald Rumsfeld

text: Rumsfeld attended Baker Demonstration School, and later graduated from New Trier High School. He attended Princeton University on academic and NROTC partial scholarships. He graduated in 1954 with an A.B. in politics after completing a senior thesis titled "The Steel Seizure Case of 1952 and Its Effects on Presidential Powers". During his time at Princeton, he was an accomplished amateur wrestler, becoming captain of the varsity wrestling team, and captain of the Lightweight Football team playing defensive back. While at Princeton he was friends with another future Secretary of Defense, Frank Carlucci.


title: Donald Rumsfeld

text: Rumsfeld married Joyce P. Pierson on December 27, 1954. They had three children, six grandchildren, and one great-grandchild. He attended Case Western Reserve University School of Law and the Georgetown University Law Center, but did not take a degree from either institution.


title: Donald Rumsfeld

text: Rumsfeld served in the United States Navy from 1954 to 1957, as a naval aviator and flight instructor. His initial training was in the North American SNJ Texan basic trainer after which he transitioned to the T-28 advanced trainer. In 1957, he transferred to the Naval Reserve and continued his naval service in flying and administrative assignments as a drilling reservist. On July 1, 1958, he was assigned to Anti-submarine Squadron 662 at Naval Air Station Anacostia, District of Columbia, as a selective reservist. Rumsfeld was designated aircraft commander of Anti-submarine Squadron 731 on October 1, 1960, at Naval Air Station Grosse Ile, Michigan, where he flew the S2F Tracker. He transferred to the Individual Ready Reserve when he became Secretary of Defense in 1975 and retired with the rank of captain in 1989.


title: Donald Rumsfeld

text: In 1957, during the Dwight D. Eisenhower administration, Rumsfeld served as administrative assistant to David S. Dennison Jr., a Congressman representing the 11th district of Ohio. In 1959, he moved on to become a staff assistant to Congressman Robert P. Griffin of Michigan. Engaging in a two-year stint with an investment banking firm, A. G. Becker & Co., from 1960 to 1962, Rumsfeld instead set his sights on becoming a member of Congress.


title: Donald Rumsfeld

text: He was elected to the United States House of Representatives for Illinois's 13th congressional district in 1962, at the age of 30, and was re-elected by large majorities in 1964, 1966, and 1968. While in Congress, he served on the Joint Economic Committee, the Committee on Science and Aeronautics, and the Government Operations Committee, as well as on the Subcommittees on Military and Foreign Operations. He was also a co-founder of the Japanese-American Inter-Parliamentary Council in addition to being a leading cosponsor of the Freedom of Information Act.


title: Donald Rumsfeld

text: In 1965, following the defeat of Barry Goldwater by Lyndon B. Johnson in the 1964 presidential election, which also led to the Republicans losing many seats in the House of Representatives, Rumsfeld proposed new leadership for the Republicans in the House, suggesting that representative Gerald Ford from Michigan's 5th congressional district was the most suited candidate to replace Charles A. Halleck as Republican leader. Rumsfeld, along with other members of the Republican caucus, then urged Gerald Ford to run for Republican leader. Ford eventually defeated Halleck and became House Minority Leader in 1965. The group of Republicans that encouraged Ford to run for the Republican leadership was later known as the "Young Turks". Rumsfeld later served during Ford's presidency as his chief of staff in 1974, and was chosen by Ford to succeed James Schlesinger as United States Secretary of Defense in 1975.


title: Donald Rumsfeld

text: During Rumsfeld's tenure as member of the U.S. House of Representatives, he voiced concerns about U.S. ability in the Vietnam War, saying that President Johnson and his national security team was too overconfident with how the war was being conducted. On one occasion Rumsfeld joined with other members of the House and traveled to Vietnam for a fact-finding mission to see for themselves how the war was going. The trip led to Rumsfeld believing that the South Vietnamese government was much too dependent on the United States. Rumsfeld was also unsatisfied when he received a briefing about war planning from the commander of the U.S. troops in Vietnam, General William Westmoreland. The trip led Rumsfeld to cosponsor a resolution to bring the conduct of the war to the House floor for further debate and discussion about the mismanagement which ultimately decided the fate of the war. However under constant pressure from the Johnson administration, the Democrats, who at that time held the majority at the House of Representatives, blocked the resolution from consideration.


title: Donald Rumsfeld

text: As a young Congressman, Rumsfeld attended seminars at the University of Chicago, an experience he credits with introducing him to the idea of an all volunteer military, and to the economist Milton Friedman and the Chicago School of Economics. He later took part in Friedman's PBS series "Free to Choose".


title: Donald Rumsfeld

text: During his tenure in the House, Rumsfeld voted in favor of the Civil Rights Acts of 1964 and 1968, and the Voting Rights Act of 1965.


title: Donald Rumsfeld

text: Rumsfeld resigned from Congress in 1969his fourth termto serve in the Nixon administration in a variety of executive branch positions. Nixon appointed Rumsfeld director of the United States Office of Economic Opportunity (OEO), a position with Cabinet rank. Rumsfeld had voted against the creation of OEO when he was in Congress, and, according to his 2011 memoirs, he initially rejected Nixon's offer, citing his own inherent belief that the OEO did more harm than good, and he felt that he was not the right person for the job. After much negotiation, he accepted the OEO appointment with Nixon's "assurances that he would be ... also an assistant to the President, with Cabinet-level status and an office in the White House," which "sweetened (the OEO position) with status and responsibility".