八大行星英语作文

famous for its extensive ring systemsemi-permanent features in its atmosphere, such as cloud bands and the Great Red Spot. Jupiter has sixty-three known satellites. The four largest, known satellites. The four largest, Ganymede, Callistoside; its axial tilt is over ninety degrees to the ecliptic. It has a much colder core than the other gas giants, and radiates very little heat into space.Uransubstantial atmosphere and evidence of internal geological activity. However, it is much drier than Earth and its atmosphere is ninety times as dense. Venus has no natural satellites. It is the hottest planet, with surface temperatures over 400 °C, most likely due to the amount of greenhouse gases in the atmosphere.No definitive us has twenty-seven known satellites, the largest ones being Titania, Oberon, Umbriel, Ariel and Miranda. known moons), and billions of small bodies. This last category includes asteroids, Kuiper belt objects, comets, meteoroids, and interplanetary dust. In broad terms, the charted regions of the Solar System consist of the Sun, four terrestrial inner planets, an asteroid belt composed of small rocky bodies, four gas giant outer planets, and a second belt, called the Kuiper belt, composed of icy objects. Beyond the Kuiper belt lies the

Mars is one of the eight major planets of the solar system. It is the fourth planet in our solar system from inside to outside. It belongs to the terrestrial planet(类地行星). It has a diameter of about half of the earth. The period of its revolving on its axis, is similar to the earth, while the period of its orbiting around the sun is two times of the earth . The Orange red appearance is caused by iron oxide(氧化铁)on its surface. Mars is basically a desert planet with dunes(沙丘), gravels(砂砾) everywhere. There is no liquid water on Mars. With thin carbon dioxide and dust in the atmosphere it is cold and try all year round. In winter the cold temperature can reach minus 130 degrees centigrade while in summer time it can rise to 27 degrees Celsius. Strong sand storms visit this planet every year. The Martian poles have dry ice caps with seasonal fluctuation. Mars has two moons rotating around it. Mars can be seen by the human eyes and it is slightly darker than the Venus(金星) but much brighter than Jupiter(木星). The nearest distance from Mars to the earth is about 55 millions kilometers, while the farthest distance is about 400 million kilometers.

太阳系Solar Systemsolar system consists of the Sun and the other celestial objects gravitationally bound to it: the eight planets, their 165 known moons,[1] three dwarf planets (Ceres, Pluto, and Eris and their four known moons), and billions of small bodies. This last category includes asteroids, Kuiper belt objects, comets, meteoroids, and interplanetary dust.In broad terms, the charted regions of the Solar System consist of the Sun, four terrestrial inner planets, an asteroid belt composed of small rocky bodies, four gas giant outer planets, and a second belt, called the Kuiper belt, composed of icy objects. Beyond the Kuiper belt lies the scattered disc, the heliopause, and ultimately the hypothetical Oort cloud.In order of their distances from the Sun, the planets are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. Six of the eight planets are in turn orbited by natural satellites, usually termed "moons" after Earth's Moon, and each of the outer planets is encircled by planetary rings of dust and other particles. All the planets except Earth are named after gods and goddesses from Greco-Roman mythology. The three dwarf planets are Pluto, the largest known Kuiper belt object; Ceres, the largest object in the asteroid belt; and Eris, which lies in the scattered disc.Jupiter Jupiter (5.2 AU), at 318 Earth masses, masses 2.5 times all the other planets put together. It is composed largely of hydrogen and helium. Jupiter's strong internal heat creates a number of semi-permanent features in its atmosphere, such as cloud bands and the Great Red Spot. Jupiter has sixty-three known satellites. The four largest, Ganymede, Callisto, Io, and Europa, show similarities to the terrestrial planets, such as volcanism and internal heating.[51] Ganymede, the largest satellite in the Solar System, is larger than Mercury.Saturn Saturn (9.5 AU), famous for its extensive ring system, has similarities to Jupiter, such as its atmospheric composition. Saturn is far less massive, being only 95 Earth masses. Saturn has sixty known satellites (and 3 unconfirmed); two of which, Titan and Enceladus, show signs of geological activity, though they are largely made of ice.[52] Titan is larger than Mercury and the only satellite in the Solar System with a substantial atmosphere.Uranus Uranus (19.6 AU), at 14 Earth masses, is the lightest of the outer planets. Uniquely among the planets, it orbits the Sun on its side; its axial tilt is over ninety degrees to the ecliptic. It has a much colder core than the other gas giants, and radiates very little heat into space.[53] Uranus has twenty-seven known satellites, the largest ones being Titania, Oberon, Umbriel, Ariel and Miranda.Mercury Mercury (0.4 AU) is the closest planet to the Sun and the smallest planet (0.055 Earth masses). Mercury has no natural satellites, and its only known geological features besides impact craters are "wrinkle-ridges", probably produced by a period of contraction early in its history.[36] Mercury's almost negligible atmosphere consists of atoms blasted off its surface by the solar wind.[37] Its relatively large iron core and thin mantle have not yet been adequately explained. Hypotheses include that its outer layers were stripped off by a giant impact, and that it was prevented from fully accreting by the young Sun's energy.[38][39]Venus Venus (0.7 AU) is close in size to Earth (0.815 Earth masses) and, like Earth, has a thick silicate mantle around an iron core, a substantial atmosphere and evidence of internal geological activity. However, it is much drier than Earth and its atmosphere is ninety times as dense. Venus has no natural satellites. It is the hottest planet, with surface temperatures over 400 °C, most likely due to the amount of greenhouse gases in the atmosphere.[40] No definitive evidence of current geological activity has been detected on Venus, but it has no magnetic field that would prevent depletion of its substantial atmosphere, which suggests that its atmosphere is regularly replenished by volcanic eruptions.[41]Earth Earth (1 AU) is the largest and densest of the inner planets, the only one known to have current geological activity, and the only planet known to have life. Its liquid hydrosphere is unique among the terrestrial planets, and it is also the only planet where plate tectonics has been observed. Earth's atmosphere is radically different from those of the other planets, having been altered by the presence of life to contain 21% free oxygen.[42] It has one satellite, the Moon, the only large satellite of a terrestrial planet in the Solar System.Mars Mars (1.5 AU) is smaller than Earth and Venus (0.107 Earth masses). It possesses a tenuous atmosphere of mostly carbon dioxide. Its surface, peppered with vast volcanoes such as Olympus Mons and rift valleys such as Valles Marineris, shows geological activity that may have persisted until very recently.[43] Mars has two tiny natural satellites (Deimos and Phobos) thought to be captured asteroids.[44] 我听说英文的维基百科已经可以在中国使用了，所以你直接去wikipedia查就可以了。 Neptune Neptune (30 AU), though slightly smaller than Uranus, is more massive (equivalent to 17 Earths) and therefore denser. It radiates more internal heat, but not as much as Jupiter or Saturn.[54] Neptune has thirteen known satellites. The largest, Triton, is geologically active, with geysers of liquid nitrogen.[55] Triton is the only large satellite with a retrograde orbit. Neptune is accompanied in its orbit by a number of minor planets in a 1:1 resonance with it, termed Neptune Trojans.

Jupiter Jupiter (5.2 AU), at 318 Earth masses, masses 2.5 times all the other planets put together. It is composed largely of hydrogen and helium. Jupiter's strong internal heat creates a number of semi-permanent features in its atmosphere, such as cloud bands and the Great Red Spot. Jupiter has sixty-three known satellites. The four largest, Ganymede, Callisto, Io, and Europa, show similarities to the terrestrial planets, such as volcanism and internal heating.Ganymede, the largest satellite in the Solar System, is larger than Mercury. Saturn Saturn (9.5 AU), famous for its extensive ring system, has similarities to Jupiter, such as its atmospheric composition. Saturn is far less massive, being only 95 Earth masses. Saturn has sixty known satellites (and 3 unconfirmed); two of which, Titan and Enceladus, show signs of geological activity, though they are largely made of ice.Titan is larger than Mercury and the only satellite in the Solar System with a substantial atmosphere. Uranus Uranus (19.6 AU), at 14 Earth masses, is the lightest of the outer planets. Uniquely among the planets, it orbits the Sun on its side; its axial tilt is over ninety degrees to the ecliptic. It has a much colder core than the other gas giants, and radiates very little heat into space.Uranus has twenty-seven known satellites, the largest ones being Titania, Oberon, Umbriel, Ariel and Miranda. Mercury Mercury (0.4 AU) is the closest planet to the Sun and the smallest planet (0.055 Earth masses). Mercury has no natural satellites, and its only known geological features besides impact craters are "wrinkle-ridges", probably produced by a period of contraction early in its history.Mercury's almost negligible atmosphere consists of atoms blasted off its surface by the solar wind.Its relatively large iron core and thin mantle have not yet been adequately explained. Hypotheses include that its outer layers were stripped off by a giant impact, and that it was prevented from fully accreting by the young Sun's energy. Venus Venus (0.7 AU) is close in size to Earth (0.815 Earth masses) and, like Earth, has a thick silicate mantle around an iron core, a substantial atmosphere and evidence of internal geological activity. However, it is much drier than Earth and its atmosphere is ninety times as dense. Venus has no natural satellites. It is the hottest planet, with surface temperatures over 400 °C, most likely due to the amount of greenhouse gases in the atmosphere.No definitive evidence of current geological activity has been detected on Venus, but it has no magnetic field that would prevent depletion of its substantial atmosphere, which suggests that its atmosphere is regularly replenished by volcanic eruptions. Earth Earth (1 AU) is the largest and densest of the inner planets, the only one known to have current geological activity, and the only planet known to have life. Its liquid hydrosphere is unique among the terrestrial planets, and it is also the only planet where plate tectonics has been observed. Earth's atmosphere is radically different from those of the other planets, having been altered by the presence of life to contain 21% free oxygen.It has one satellite, the Moon, the only large satellite of a terrestrial planet in the Solar System. Mars Mars (1.5 AU) is smaller than Earth and Venus (0.107 Earth masses). It possesses a tenuous atmosphere of mostly carbon dioxide. Its surface, peppered with vast volcanoes such as Olympus Mons and rift valleys such as Valles Marineris, shows geological activity that may have persisted until very recently.Mars has two tiny natural satellites (Deimos and Phobos) thought to be captured asteroids. Neptune Neptune (30 AU), though slightly smaller than Uranus, is more massive (equivalent to 17 Earths) and therefore denser. It radiates more internal heat, but not as much as Jupiter or Saturn.Neptune has thirteen known satellites. The largest, Triton, is geologically active, with geysers of liquid nitrogen.Triton is the only large satellite with a retrograde orbit. Neptune is accompanied in its orbit by a number of minor planets in a 1:1 resonance with it, termed Neptune Trojans. 回答者： luorichard321 - 高级魔法师 六级 1-10 14:36太阳系Solar System solar system consists of the Sun and the other celestial objects gravitationally bound to it: the eight planets, their 165 known moons,[1] three dwarf planets (Ceres, Pluto, and Eris and their four known moons), and billions of small bodies. This last category includes asteroids, Kuiper belt objects, comets, meteoroids, and interplanetary dust. In broad terms, the charted regions of the Solar System consist of the Sun, four terrestrial inner planets, an asteroid belt composed of small rocky bodies, four gas giant outer planets, and a second belt, called the Kuiper belt, composed of icy objects. Beyond the Kuiper belt lies the scattered disc, the heliopause, and ultimately the hypothetical Oort cloud. In order of their distances from the Sun, the planets are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. Six of the eight planets are in turn orbited by natural satellites, usually termed "moons" after Earth's Moon, and each of the outer planets is encircled by planetary rings of dust and other particles. All the planets except Earth are named after gods and goddesses from Greco-Roman mythology. The three dwarf planets are Pluto, the largest known Kuiper belt object; Ceres, the largest object in the asteroid belt; and Eris, which lies in the scattered disc. Jupiter Jupiter (5.2 AU), at 318 Earth masses, masses 2.5 times all the other planets put together. It is composed largely of hydrogen and helium. Jupiter's strong internal heat creates a number of semi-permanent features in its atmosphere, such as cloud bands and the Great Red Spot. Jupiter has sixty-three known satellites. The four largest, Ganymede, Callisto, Io, and Europa, show similarities to the terrestrial planets, such as volcanism and internal heating.[51] Ganymede, the largest satellite in the Solar System, is larger than Mercury. Saturn Saturn (9.5 AU), famous for its extensive ring system, has similarities to Jupiter, such as its atmospheric composition. Saturn is far less massive, being only 95 Earth masses. Saturn has sixty known satellites (and 3 unconfirmed); two of which, Titan and Enceladus, show signs of geological activity, though they are largely made of ice.[52] Titan is larger than Mercury and the only satellite in the Solar System with a substantial atmosphere. Uranus Uranus (19.6 AU), at 14 Earth masses, is the lightest of the outer planets. Uniquely among the planets, it orbits the Sun on its side; its axial tilt is over ninety degrees to the ecliptic. It has a much colder core than the other gas giants, and radiates very little heat into space.[53] Uranus has twenty-seven known satellites, the largest ones being Titania, Oberon, Umbriel, Ariel and Miranda. Mercury Mercury (0.4 AU) is the closest planet to the Sun and the smallest planet (0.055 Earth masses). Mercury has no natural satellites, and its only known geological features besides impact craters are "wrinkle-ridges", probably produced by a period of contraction early in its history.[36] Mercury's almost negligible atmosphere consists of atoms blasted off its surface by the solar wind.[37] Its relatively large iron core and thin mantle have not yet been adequately explained. Hypotheses include that its outer layers were stripped off by a giant impact, and that it was prevented from fully accreting by the young Sun's energy.[38][39] Venus Venus (0.7 AU) is close in size to Earth (0.815 Earth masses) and, like Earth, has a thick silicate mantle around an iron core, a substantial atmosphere and evidence of internal geological activity. However, it is much drier than Earth and its atmosphere is ninety times as dense. Venus has no natural satellites. It is the hottest planet, with surface temperatures over 400 °C, most likely due to the amount of greenhouse gases in the atmosphere.[40] No definitive evidence of current geological activity has been detected on Venus, but it has no magnetic field that would prevent depletion of its substantial atmosphere, which suggests that its atmosphere is regularly replenished by volcanic eruptions.[41] Earth Earth (1 AU) is the largest and densest of the inner planets, the only one known to have current geological activity, and the only planet known to have life. Its liquid hydrosphere is unique among the terrestrial planets, and it is also the only planet where plate tectonics has been observed. Earth's atmosphere is radically different from those of the other planets, having been altered by the presence of life to contain 21% free oxygen.[42] It has one satellite, the Moon, the only large satellite of a terrestrial planet in the Solar System. Mars Mars (1.5 AU) is smaller than Earth and Venus (0.107 Earth masses). It possesses a tenuous atmosphere of mostly carbon dioxide. Its surface, peppered with vast volcanoes such as Olympus Mons and rift valleys such as Valles Marineris, shows geological activity that may have persisted until very recently.[43] Mars has two tiny natural satellites (Deimos and Phobos) thought to be captured asteroids.[44] 我听说英文的维基百科已经可以在中国使用了，所以你直接去wikipedia查就可以了。 Neptune Neptune (30 AU), though slightly smaller than Uranus, is more massive (equivalent to 17 Earths) and therefore denser. It radiates more internal heat, but not as much as Jupiter or Saturn.[54] Neptune has thirteen known satellites. The largest, Triton, is geologically active, with geysers of liquid nitrogen.[55] Triton is the only large satellite with a retrograde orbit. Neptune is accompanied in its orbit by a number of minor planets in a 1:1 resonance with it, termed Neptune Trojans.

Mercury (水星): ——The Mercury is the smallest of the planets and the one nearest the sun, having a sidereal period of revolution about the sun of 88 days (水星是行星中最小且离太阳最近的星，围绕太阳公转所需的周期为88天。) Mars (火星): ——The Mars is the fourth planet from the sun, having a sidereal period of revolution about the sun of 687 days. (火星是距太阳距离居第四位的行星，绕太阳公转周期为687天，). Venus (金星): ——The Hesper is the planet Venus in its appearance. The Venus is the second planet from the sun, having a mass 0.815 times that of Earth, and a sidereal period of revolution about the sun of 224.7 days. When appearing as the evening star, it can be called Hesper/Hesperus. (金星是离太阳第二远的行星，它的质量是地球质量的0.815倍，绕太阳转的公转周期为224.7天。傍晚出现时称作长庚星) Saturn (土星): ——It is the sixth planet from the sun and the second largest in the solar system, having a sidereal period of revolution about the sun of 29.5 years and a mass 95 times that of Earth. (土星是距太阳第六远的行星，是太阳系中第二大行星，绕日公转周期29.5年，质量是地球的95倍。) Jupiter (木星): ——The Jupiter is the fifth planet from the sun, the largest and most massive in the solar system, having a sidereal period of revolution about the sun of 11.86 years. (木星是靠近太阳的第5颗行星，也是太阳系中最大的行星，绕太阳公转的恒星期为11.86年。) Uranus (天王星): ——The Uranus is the seventh planet from the sun, revolving about it every 84.07 years. (是离太阳第七近的行星，每绕太阳一周为84.07年。) Neptune (海王星): ——The Neptune is the eighth planet from the sun, having a sidereal period of revolution around the sun of 164.8 years.（是太阳的第八颗行星。围绕太阳公转的恒星周期为164.8年） Pluto (冥王星): ——The Pluto used to be the ninth planet in the solar system, but now it is listed as the Dwarf Planet. （冥王星曾经是太阳系的第九颗行星，但是现在被列为矮行星。）

MercuryMercury is the closest planet to the sun. Its cratered surface can reach upwards of 800 degrees fahrenheit because of its proximity to the sun and its slow rotation. Only slightly larger than Earth's moon, it is the smallest planet in the solar system. It has no moons, no rings, and a very thin atmosphere.VenusThe second planet from the sun, Venus, is slightly smaller than Earth. Because of its relative proximity to Earth, it is the largest planet seen in the night sky. The cratered surface of the planet is hot, with surface temperatures around 900 degrees fahrenheit. Venus has a thick atmosphere of sulfuric acid and carbon dioxide. The density of its atmosphere makes the air pressure 90 times that of Earth's. This makes the planet decidedly inhospitable to life.MarsMars, also called the Red Planet, is the solar system's fourth planet. Its surface is characterized by dust storms, large volcanoes and deep valleys. The red color of the surface comes from iron oxide or rust in the soil. Some of the surface features of Mars, such as dry river beds, hint toward water previously existing on the planet. The atmosphere is very thin on Mars, with only 1/100th the air pressure of Earth, and the planet is relatively cold with surface temperatures ranging from -171 to 32 degrees fahrenheit.JupiterFurther from the sun, past a ring of asteroids, lies the largest planet in our solar system -- Jupiter -- the first of the gas giant planets. Its characteristic colored cloud patterns are caused by enormous, swirling storms in its atmosphere. The largest and most distinctive of these, the Great Red Spot, is large enough to swallow Earth. The interior of this great planet is mostly hydrogen and helium. Jupiter has 63 moons and a faint ring system.SaturnSaturn, the sixth planet from the sun and the second gas giant, is unique in that an extensive and complex set of rings orbit the planet in a thin band. Saturn is large -- about 9.5 times the radius of Earth. It has 62 moons in its orbit. The interior of Saturn, like Jupiter, is made of mostly hydrogen and helium in liquid form because of the strong pressure there.UranusWhile most planets spin on their axis with a slight tilt, the gas giant Uranus spins on a plane with the orbit of the sun. This creates unique seasonal changes. This cold planet is four times the diameter of Earth, and is made of a large atmosphere of methane with a dense core of frozen methane. Uranus has a faint ring system and 27 moons in its orbit.NeptuneThe blue planet Neptune is the farthest from the sun and, like Uranus, is a very cold place. Because of its distance from the sun, one year on Neptune is 165 Earth years. The large amount of methane in the atmosphere gives the planet its blue color, and the cold interior of the planet is mainly methane ice. It is a relatively large planet. Also like Uranus, it has a diameter roughly four times that of Earth. Thirteen moons and a faint ring system orbit the planet.需要说明的是，8大行星里没有冥王星，因为在2006年8月24日召开的国际天文学联合会第26届大会，经两千余天文学家表决通过———太阳系只有八大行星。不再将传统九大行星之一的冥王星视为行星，而将其列入“矮行星”