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Planetshine
Planetshine is the dim illumination, by sunlight reflected from a planet, of all or part of the otherwise dark side of any moon orbiting the body. Planetlight is the diffuse reflection of sunlight from a planet, whose albedo can be measured. The most observed and familiar example of planetshine is earthshine on the Moon, which is most visible from the night side of Earth when the lunar phase is crescent or nearly new, without the atmospheric brightness of the daytime sky. Typically, this results in the dark side of the Moon being bathed in a faint light. Planetshine has also been observed elsewhere in the Solar System. In particular, the ''Cassini'' space probe used Saturn's shine to image portions of the planet's moons, even when they do not reflect direct sunlight. The '' New Horizons'' space probe similarly used Charon's shine to discover albedo variations on Pluto's dark side. Although using a geocentric model in 510 AD, Indian mathematician and astronomer Aryabhata ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lunar Phase
Concerning the lunar month of ~29.53 days as viewed from Earth, the lunar phase or Moon phase is the shape of the Moon's directly sunlit portion, which can be expressed quantitatively using areas or angles, or described qualitatively using the terminology of the 4 major phases: new moon, first quarter, full moon, last quarter and 4 minor phases: waxing crescent, waxing gibbous, waning gibbous, and waning crescent. The lunar phases gradually change over a synodic month (~29.53 days) as the Moon's orbital positions around Earth and Earth around the Sun shift. The visible side of the Moon is variously sunlit, depending on the position of the Moon in its orbit. Thus, this face's sunlit portion can vary from 0% (at new moon) to 100% (at full moon). Each of the 4 major lunar phases (see below) is ~7.4 days, with +/− 19 hours in variation (6.58–8.24 days) due to the elliptical shape of the Moon's orbit. Phases of the Moon There are four ''principal'' (primary/major) lunar phases: ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lunar Phase
Concerning the lunar month of ~29.53 days as viewed from Earth, the lunar phase or Moon phase is the shape of the Moon's directly sunlit portion, which can be expressed quantitatively using areas or angles, or described qualitatively using the terminology of the 4 major phases: new moon, first quarter, full moon, last quarter and 4 minor phases: waxing crescent, waxing gibbous, waning gibbous, and waning crescent. The lunar phases gradually change over a synodic month (~29.53 days) as the Moon's orbital positions around Earth and Earth around the Sun shift. The visible side of the Moon is variously sunlit, depending on the position of the Moon in its orbit. Thus, this face's sunlit portion can vary from 0% (at new moon) to 100% (at full moon). Each of the 4 major lunar phases (see below) is ~7.4 days, with +/− 19 hours in variation (6.58–8.24 days) due to the elliptical shape of the Moon's orbit. Phases of the Moon There are four ''principal'' (primary/major) lunar phases: ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mimas Double Terminator
Mimas may refer to: * Mimas (Giant), son of Gaia in Greek mythology, one of the Gigantes * Mimas (''Aeneid''), a son of Amycus and Theono, born the same night as Paris, who escorted Aeneas to Italy * Karaburun, a town and district in Turkey, formerly called Mimas in reference to the Giant *Mimas (moon), in astronomy, a moon of Saturn marked by a giant crater on its surface * ''Mimas'' (moth), a genus of hawk moths *Mimas (data centre), a UK national academic data centre at the University of Manchester * Mimas, a centaur mentioned in the archaic Greek epic poem, the ''Shield of Heracles'', at line 182 * Mimas, grandfather of Aeolus In Greek mythology, Aeolus or Aiolos (; grc, Αἴολος , ) is a name shared by three mythical characters. These three personages are often difficult to tell apart, and even the ancient mythographers appear to have been perplexed about which A ..., the keeper of the winds in Homer's ''Odyssey'' Pronounced with a final /z/ sound, it may be: * Mima mou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saturn
Saturn is the sixth planet from the Sun and the second-largest in the Solar System, after Jupiter. It is a gas giant with an average radius of about nine and a half times that of Earth. It has only one-eighth the average density of Earth; however, with its larger volume, Saturn is over 95 times more massive. Saturn's interior is most likely composed of a core of iron–nickel alloy, iron–nickel and rock (silicon and oxygen compounds). Its core is surrounded by a deep layer of metallic hydrogen, an intermediate layer of liquid hydrogen and liquid helium, and finally, a gaseous outer layer. Saturn has a pale yellow hue due to ammonia crystals in its upper atmosphere. An electrical current within the metallic hydrogen layer is thought to give rise to Saturn's planetary magnetic field, which is weaker than Earth's, but which has a magnetic moment 580 times that of Earth due to Saturn's larger size. Saturn's magnetic field strength is around one-twentieth of Jupiter's. The out ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leonardo Da Vinci
Leonardo di ser Piero da Vinci (15 April 14522 May 1519) was an Italian polymath of the High Renaissance who was active as a painter, Drawing, draughtsman, engineer, scientist, theorist, sculptor, and architect. While his fame initially rested on his achievements as a painter, he also became known for #Journals and notes, his notebooks, in which he made drawings and notes on a variety of subjects, including anatomy, astronomy, botany, cartography, painting, and paleontology. Leonardo is widely regarded to have been a genius who epitomized the Renaissance humanism, Renaissance humanist ideal, and his List of works by Leonardo da Vinci, collective works comprise a contribution to later generations of artists matched only by that of his younger contemporary, Michelangelo. Born Legitimacy (family law), out of wedlock to a successful Civil law notary, notary and a lower-class woman in, or near, Vinci, Tuscany, Vinci, he was educated in Florence by the Italian painter and sculptor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Earth Illuminates
Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's surface is made up of the ocean, dwarfing Earth's polar ice, lakes, and rivers. The remaining 29% of Earth's surface is land, consisting of continents and islands. Earth's surface layer is formed of several slowly moving tectonic plates, which interact to produce mountain ranges, volcanoes, and earthquakes. Earth's liquid outer core generates the magnetic field that shapes the magnetosphere of the Earth, deflecting destructive solar winds. The atmosphere of the Earth consists mostly of nitrogen and oxygen. Greenhouse gases in the atmosphere like carbon dioxide (CO2) trap a part of the energy from the Sun close to the surface. Water vapor is widely present in the atmosphere and forms clouds that cover most of the planet. More solar energy is rec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sunlight
Sunlight is a portion of the electromagnetic radiation given off by the Sun, in particular infrared, visible, and ultraviolet light. On Earth, sunlight is scattered and filtered through Earth's atmosphere, and is obvious as daylight when the Sun is above the horizon. When direct solar radiation is not blocked by clouds, it is experienced as sunshine, a combination of bright light and radiant heat. When blocked by clouds or reflected off other objects, sunlight is diffused. Sources estimate a global average of between 164 watts to 340 watts per square meter over a 24-hour day; this figure is estimated by NASA to be about a quarter of Earth's average total solar irradiance. The ultraviolet radiation in sunlight has both positive and negative health effects, as it is both a requisite for vitamin D3 synthesis and a mutagen. Sunlight takes about 8.3 minutes to reach Earth from the surface of the Sun. A photon starting at the center of the Sun and changing direction ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sir Patrick Spens
"Sir Patrick Spens" is one of the most popular of the Child Ballads (No. 58) ( Roud 41), and is of Scottish origin. It is a maritime ballad about a disaster at sea. Background ''Sir Patrick Spens'' remains one of the most anthologized of British popular ballads, partly because it exemplifies the traditional ballad form. The strength of this ballad, its emotional force, lies in its unadorned narrative which progresses rapidly to a tragic end that has been foreshadowed almost from the beginning. It was first published in eleven stanzas in 1765 in Bishop Thomas Percy's ''Reliques of Ancient English Poetry'', based on "two MS. copies transmitted from Scotland". The protagonist is referred to as "young Patrick Spens" in some versions of the ballad. Plot The story as told in the ballad has multiple versions, but they all follow the same basic plot. The King of Scotland has called for the greatest sailor in the land to command a ship for a royal errand. The name "Sir Patrick Spens ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Earthshine Diagram
Earthlight is the diffuse reflection of sunlight reflected from Earth's surface and clouds. Earthshine (an example of planetshine), also known as the Moon's ashen glow, is the dim illumination of the otherwise unilluminated portion of the Moon by this indirect sunlight. Earthlight on the Moon during the waxing crescent is called "the old Moon in the new Moon's arms", while that during the waning crescent is called "the new Moon in the old Moon's arms". Earthlight has a calculated maximum apparent magnitude of −17.7 as viewed from the Moon. Earthshine has a calculated maximum apparent magnitude of −3.69 as viewed from Earth. This phenomenon is most visible from Earth at night (or astronomical twilight) a few days before or after the day of new moon, when the lunar phase is a thin crescent. On these nights, the entire lunar disk is both directly and indirectly sunlit, and is thus unevenly bright enough to see. Earthshine is most clearly seen after dusk during the waxing cresc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aryabhatiya
''Aryabhatiya'' (IAST: ') or ''Aryabhatiyam'' ('), a Sanskrit astronomical treatise, is the '' magnum opus'' and only known surviving work of the 5th century Indian mathematician Aryabhata. Philosopher of astronomy Roger Billard estimates that the book was composed around 510 CE based on historical references it mentions. Structure and style Aryabhatiya is written in Sanskrit and divided into four sections; it covers a total of 121 verses describing different moralitus via a mnemonic writing style typical for such works in India (see definitions below): 1. Gitikapada (13 verses): large units of time— kalpa, manvantara, and yuga—which present a cosmology different from earlier texts such as Lagadha's Vedanga Jyotisha (ca. 1st century BCE). There is also a table of ine (jya), given in a single verse. The duration of the planetary revolutions during a mahayuga is given as 4.32 million years. 2. Ganitapada (33 verses): covering mensuration (kṣetra vyāvahāra); arithmetic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aryabhata
Aryabhata ( ISO: ) or Aryabhata I (476–550 CE) was an Indian mathematician and astronomer of the classical age of Indian mathematics and Indian astronomy. He flourished in the Gupta Era and produced works such as the ''Aryabhatiya'' (which mentions that in 3600 ''Kali Yuga'', 499 CE, he was 23 years old) and the ''Arya-siddhanta.'' Aryabhata created a system of phonemic number notation in which numbers were represented by consonant-vowel monosyllables. Later commentators such as Brahmagupta divide his work into ''Ganita ("Mathematics"), Kalakriya ("Calculations on Time") and Golapada ("Spherical Astronomy")''. His pure mathematics discusses topics such as determination of square and cube roots, geometrical figures with their properties and mensuration, arithmetric progression problems on the shadow of the gnomon, quadratic equations, linear and indeterminate equations. Aryabhata calculated the value of pi (''π)'' to the fourth decimal digit and was likely aware that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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