"the relationship between the formation of the planets and their internal structure, for the gas giants Jupiter and Saturn, and the ice giants Neptune and Uranus. The processes that lead to the formation of planets in our solar system are compared to the formation of exoplanets. The study also examines whether a uniform mechanism can be found predicting the formation of the planets, and the differences between different planetary systems and the physical processes that influence the formation of planets in a particular system. Helled's research group also examines the internal structure of the planets and their composition. In the"
"on a mathematical analysis of the planet's ability to scatter other objects out of its orbit over a long period of time. Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune were classified as neighborhood-clearing ""überplanets"" and Pluto was classified as an ""unterplanet"". One could take this classification system as planet and dwarf planet respectively, with the major difference of the IAU definition classifying the two as distinct categories of celestial bodies instead of two subsets of planets. Some large satellites are of similar size or larger than the planet Mercury, e.g. Jupiter's Galilean moons and Titan. Stern has argued"
"by Jupiter. Neptune's equatorial radius of 24,764 km is nearly four times that of Earth. Neptune, like Uranus, is an ice giant, a subclass of giant planet, because they are smaller and have higher concentrations of volatiles than Jupiter and Saturn. In the search for extrasolar planets, Neptune has been used as a metonym: discovered bodies of similar mass are often referred to as ""Neptunes"", just as scientists refer to various extrasolar bodies as ""Jupiters"". Neptune's internal structure resembles that of Uranus. Its atmosphere forms about 5% to 10% of its mass and extends perhaps 10% to 20% of the"
"not much is yet known about it. Generational planet In the field of astrology, generational planets are planets that affect an entire generation of people. The generational planets are the outer planets Uranus, Neptune, Pluto, Sedna, and Quaoar. Uranus was discovered by amateur astronomer William Herschel on 13 March 1781. Uranus exhibits the ideals of the 18th century, where people such as Benjamin Franklin endeavoured to use their inventive mind to move man into a more enlightened era. It has an orbit of 84 years, staying in each sign of the zodiac for approximately 7 years. Uranus is considered to"
"Generational planet In the field of astrology, generational planets are planets that affect an entire generation of people. The generational planets are the outer planets Uranus, Neptune, Pluto, Sedna, and Quaoar. Uranus was discovered by amateur astronomer William Herschel on 13 March 1781. Uranus exhibits the ideals of the 18th century, where people such as Benjamin Franklin endeavoured to use their inventive mind to move man into a more enlightened era. It has an orbit of 84 years, staying in each sign of the zodiac for approximately 7 years. Uranus is considered to be a higher octave of Mercury, which"
"Since the dawn of the Space Age, close observation by space probes has found that Earth and the other planets share characteristics such as volcanism, hurricanes, tectonics, and even hydrology. Planets are generally divided into two main types: large low-density giant planets, and smaller rocky terrestrials. There are eight planets in the Solar System. In order of increasing distance from the Sun, they are the four terrestrials, Mercury, Venus, Earth, and Mars, then the four giant planets, Jupiter, Saturn, Uranus, and Neptune. Six of the planets are orbited by one or more natural satellites. Several thousands of planets around other"
"Sometimes, the Sun and Moon were referred to as ""the lights"" or the ""luminaries"". Vesta and Uranus can also just be seen with the naked eye, though no ancient culture appears to have taken note of them. The astrological descriptions attached to the seven classical planets have been preserved since ancient times. Astrologers call the seven classical planets ""the seven personal and social planets"", because they are said to represent the basic human drives of every individual. The personal planets are the Sun, Moon, Mercury, Venus and Mars. The social or transpersonal planets are Jupiter and Saturn. Jupiter and Saturn"
"Uranus and Neptune are far less massiveless than 20 Earth masses () eachand are composed primarily of ices. For these reasons, some astronomers suggest they belong in their own category, ice giants. All four giant planets have rings, although only Saturn's ring system is easily observed from Earth. The term ""superior planet"" designates planets outside Earth's orbit and thus includes both the outer planets and Mars. The centaurs are icy comet-like bodies whose orbits have semi-major axes greater than Jupiter's (5.5 AU) and less than Neptune's (30 AU). The largest known centaur, 10199 Chariklo, has a diameter of about 250"
"the term only for the planets similar to the latter two. With this terminology in mind, some astronomers have started referring to Uranus and Neptune as ice giants to indicate the predominance of the ""ices"" (in fluid form) in their interior composition. The alternative term ""jovian planet"" refers to the Roman god Jupiter—the genitive form of which is ""Jovis"", hence ""Jovian""—and was intended to indicate that all of these planets were similar to Jupiter. Objects large enough to start deuterium fusion (above 13 Jupiter masses for solar composition) are called brown dwarfs, and these occupy the mass range between that"
"Classical planet In classical antiquity, the seven classical planets were the seven non-fixed astronomical objects in the sky visible to the naked eye: Mars, Jupiter, Venus, Saturn, Mercury, the Sun, and the Moon. The word ""planet"" comes from two related Greek words, πλάνης ""planēs"" (whence πλάνητες ἀστέρες ""planētes asteres"" ""wandering stars, planets"") and πλανήτης ""planētēs"", both with the original meaning of ""wanderer"", expressing the fact that these objects move across the celestial sphere relative to the fixed stars. The term ""planet"" in modern terminology is only applied to natural satellites directly orbiting the Sun, so that of the seven classical"
"mostly of water, methane, and ammonia. There is also some rock and gas, but various proportions of ice–rock–gas could mimic pure ice, so that the exact proportions are unknown. Uranus and Neptune have very hazy atmospheric layers with small amounts of methane, giving them aquamarine colors; light blue and ultramarine respectively. Both have magnetic fields that are sharply inclined to their axes of rotation. Unlike the other giant planets, Uranus has an extreme tilt that causes its seasons to be severely pronounced. The two planets also have other subtle but important differences. Uranus has more hydrogen and helium than Neptune"
"Neptune Neptune is the eighth and farthest known planet from the Sun in the Solar System. In the Solar System, it is the fourth-largest planet by diameter, the third-most-massive planet, and the densest giant planet. Neptune is 17 times the mass of Earth and is slightly more massive than its near-twin Uranus, which is 15 times the mass of Earth and slightly larger than Neptune. Neptune orbits the Sun once every 164.8 years at an average distance of . It is named after the Roman god of the sea and has the astronomical symbol ♆, a stylised version of the"
"that—like Pluto—Earth, Mars, Jupiter and Neptune have not cleared their orbital neighbourhoods either. Earth co-orbits with 10,000 near-Earth asteroids (NEAs), and Jupiter has 100,000 trojans in its orbital path. ""If Neptune had cleared its zone, Pluto wouldn't be there"", he has said. However, Stern himself co-developed one of the measurable discriminants: Stern and Levison's ""Λ"". In that context he stated, ""we define an ""überplanet"" as a planetary body in orbit about a star that is dynamically important enough to have cleared its neighboring planetesimals ..."" and a few paragraphs later, ""From a dynamical standpoint, our solar system clearly contains 8"
"in the image, with bits going to the right and more significant digits below. Earth The solar system, showing the Sun and the planets in the order of their position from the Sun: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto. (Pluto has since been reclassified as a dwarf planet by the International Astronomical Union, but it was still considered a planet at the time the message was transmitted.) The Earth is the third planet from the Sun; its graphic is shifted up to identify it as the planet from which the signal was sent. Additionally, the human"
"the Sun, and Vesta in order of discovery. When Ceres (1801), Pallas (1802), Juno (1804) and Vesta (1807) were discovered in the 19th century, they were known as planets, and Neptune was not discovered until 1846, there were a total of eleven planets. At the time, even Uranus had been recognized as a planet for twenty years. However, the number of planets rapidly grew from 1850 onward, and Ceres, Pallas, Juno, and Vesta were re-classified as asteroids one, two, three, and four; the number of recognized planets dropped to eight until the discovery of Pluto in 1930. For example, in"
"means that as people develop within their selves, their character and means of communication will exhibit more influences of the sign and house of Uranus. In essence, Uranus can be seen as a person's higher self. Because it takes Uranus 84 years to travel through the zodiac, transiting Uranus just might conjoin the natal Uranus within a person's lifetime. Neptune was discovered on 23 September 1846. Neptune is a 19th-century planet in that it heralded in many of the varied assortment of Protestant religions, as well as spiritualism, took hold. Visionaries such as Edgar Cayce and Rudolf Steiner were born"
"seven corresponds to the seven classical planets known to antiquity. Ancient observers noticed that these objects moved at different paces in the sky both from each other and from the fixed stars beyond them: Mercury, Venus, the Moon, the Sun, Mars, Jupiter, and Saturn. Unlike comets, which appeared in the sky with no warning, they did move in regular patterns that could be predicted. They also observed that objects in the sky influenced objects on earth, as when movements of the sun affect the behavior of plants or movements of the moon affect ocean tides. While others believe the seven"
"same composition as the Sun, but the planets could also have formed when a solid core captured nebular gas. In current models, the four giant planets have cores of rock and ice that are roughly the same size, but the proportion of hydrogen and helium decreases from about 300 Earth masses in Jupiter to 75 in Saturn and just a few in Uranus and Neptune. Thus, while the gas giants are primarily composed of hydrogen and helium, the ice giants are primarily composed of heavier elements (O, C, N, S), primarily in the form of water, methane and ammonia. The"
"are often called the first of the ""transpersonal"" or ""transcendent"" planets as they represent a transition from the inner personal planets to the outer modern, impersonal planets. The outer modern planets Uranus, Neptune and Pluto are often called the collective or transcendental planets. The following is a list of the planets and their associated characteristics. The Sun () is the ruling planet of Leo and is exalted in Aries. In classical Greek mythology, the Sun was represented by the Titans Hyperion and Helios (Roman Sol, and later by Apollo, the god of light). The Sun is the star at the"
"When subsequent planets were discovered in the 18th and 19th centuries, the naming practice was retained with ""Neptūnus"" (Poseidon). Uranus is unique in that it is named for a Greek deity rather than his Roman counterpart. 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"
"Jove et Marte"" (""""The outer planets: Saturn, Jupiter and Mars""""), ""De Venere"" (""""Venus"""") and ""De Mercurio"" (""""Mercury""""). In this section, the heavenly spheres are given in order from outermost to innermost. The outermost sphere is that of the fixed stars, which remains perfectly stationary. Then follow those of Saturn, Jupiter, Mars, Earth, Venus and Mercury, which each revolve about the Sun from west to east with successively shorter periods of revolution, Saturn's being between 29 and 30 years, Jupiter's between 11 and 12, Mars's between 2 and 3, Earth's exactly one, Venus's between 8 and 9 months, and Mercury's between"
"the asteroids. Terrestrial planets would have no major moons which does not account for Luna. It predicts certain observations such as the similar angular velocity of Mars and Earth with similar rotation periods and axial tilts. In this scheme there are 6 principal planets: 2 terrestrial, Venus and Earth, 2 major, Jupiter and Saturn, and 2 outer, Uranus and Neptune; and 3 lesser planets: Mercury, Mars, and Pluto. This theory has a number of problems, such as explaining the fact that the planets all orbit the Sun in the same direction, which would appear highly unlikely if they were each"
"that of Uranus, is primarily composed of ices and rock, which is why Uranus and Neptune are normally considered ""ice giants"" to emphasise this distinction. Traces of methane in the outermost regions in part account for the planet's blue appearance. In contrast to the hazy, relatively featureless atmosphere of Uranus, Neptune's atmosphere has active and visible weather patterns. For example, at the time of the ""Voyager 2"" flyby in 1989, the planet's southern hemisphere had a Great Dark Spot comparable to the Great Red Spot on Jupiter. These weather patterns are driven by the strongest sustained winds of any planet"
"be visible to the naked eye and can be outshone by Jupiter's Galilean moons, the dwarf planet Ceres and the asteroids 4 Vesta, 2 Pallas, 7 Iris, 3 Juno, and 6 Hebe. A telescope or strong binoculars will resolve Neptune as a small blue disk, similar in appearance to Uranus. Because of the distance of Neptune from Earth, its angular diameter only ranges from 2.2 to 2.4 arcseconds, the smallest of the Solar System planets. Its small apparent size makes it challenging to study visually. Most telescopic data was fairly limited until the advent of the ""Hubble Space Telescope"" and"
"planets, dwarf planets, a few asteroids, our star, our planet, and our Moon. Uranium, neptunium, plutonium, cerium, and palladium were named after Uranus, Neptune, Pluto, Ceres, and Pallas respectively, which were at the time of their naming all considered to be planets. (Today, Pluto and Ceres are considered to be dwarf planets, and Pallas is considered to be an asteroid.) The name of the element selenium came from the Greek word for the Moon (Σελήνη, ""Selene""). The name helium comes from the Greek word for the Sun (Ἢλιος, ""Helios""). This is because the first evidence for helium was in distinctive,"
"Discovery and exploration of the Solar System Discovery and exploration of the Solar System is observation, visitation, and increase in knowledge and understanding of Earth's ""cosmic neighborhood"". This includes the Sun, Earth and the Moon, the major planets including Mercury, Venus, Mars, Jupiter, Saturn, Uranus, and Neptune, their satellites, as well as smaller bodies including comets, asteroids, and dust. For many thousands of years, astronomers maintained a geocentric world view and did not recognize the existence of a Solar System. Most believed Earth was stationary at the center of the Universe and categorically different from the divine or ethereal objects"
"Moons of Uranus Uranus is the seventh planet of the Solar System; it has 27 known moons, all of which are named after characters from the works of William Shakespeare and Alexander Pope. Uranus's moons are divided into three groups: thirteen inner moons, five major moons, and nine irregular moons. The inner moons are small dark bodies that share common properties and origins with Uranus's rings. The five major moons are massive enough to have reached hydrostatic equilibrium, and four of them show signs of internally driven processes such as canyon formation and volcanism on their surfaces. The largest of"
"planet in the Solar System, referred to as Planet Nine, was proposed as an explanation for the orbital behavior of six trans-Neptunian objects, but it is speculated to be instead an ice giant like Uranus or Neptune. Due to the larger mass of super-Earths, their physical characteristics may differ from Earth's; theoretical models for super-Earths provide four possible main compositions according to their density: low-density super-Earths are inferred to be composed mainly of hydrogen and helium (mini-Neptunes); super-Earths of intermediate density are inferred to either have water as a major constituent (ocean planets), or have a denser core enshrouded with"
"Gas giant A gas giant is a giant planet composed mainly of hydrogen and helium. Gas giants are sometimes known as failed stars because they contain the same basic elements as a star. Jupiter and Saturn are the gas giants of the Solar System. The term ""gas giant"" was originally synonymous with ""giant planet"", but in the 1990s it became known that Uranus and Neptune are really a distinct class of giant planet, being composed mainly of heavier volatile substances (which are referred to as ""ices""). For this reason, Uranus and Neptune are now often classified in the separate category"
"That part of the curve is generally fairly flat, like that of Venus, for these cloudy planets. The apparent magnitude of Jupiter ranges from −2.9 to −1.4, Saturn from −0.5 to +1.4, Uranus from +5.3 to +6.0, and Neptune from +7.8 to +8.0. Most of these variations are due to distance. However, the magnitude range for Saturn also depends on its ring system as explained below. The brightness of the Saturn system depends on the orientation of its ring system. The rings contribute more to the overall brightness of the system when they are more inclined to the direction of"
"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). There is no official definition of extrasolar planets. In 2003, the International Astronomical Union (IAU) Working Group on Extrasolar Planets issued a position statement, but this position statement was never proposed as an official IAU resolution and was never voted on by IAU members. The positions statement incorporates the following guidelines, mostly focused upon the boundary between planets and brown dwarfs: This"
"According to Plato, the Earth was a sphere, stationary at the center of the universe. The stars and planets were carried around the Earth on spheres or circles, arranged in the order (outwards from the center): Moon, Sun, Venus, Mercury, Mars, Jupiter, Saturn, fixed stars, with the fixed stars located on the celestial sphere. In his ""Myth of Er"", a section of the ""Republic"", Plato describes the cosmos as the Spindle of Necessity, attended by the Sirens and turned by the three Fates. Eudoxus of Cnidus, who worked with Plato, developed a less mythical, more mathematical explanation of the planets'"
"accepted by most astrologers. Uranus () is the ruling planet of Aquarius and is exalted in Scorpio. In classical Greek mythology, Uranus is the personification of the sky. The planet Uranus is very unusual among the planets in that it rotates on its side, so that it presents each of its poles to the Sun in turn during its orbit; causing both hemispheres to alternate between being bathed in light and lying in total darkness over the course of the orbit. Uranus takes 84 years to orbit the Sun, spending about 7 years in each sign of the zodiac. Uranus"