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Lunar Node
A lunar node is either of the two orbital nodes of the Moon; that is, the two points at which the orbit of the Moon intersects the ecliptic. The ''ascending'' (or ''north'') node is where the Moon moves into the northern ecliptic hemisphere, while the ''descending'' (or ''south'') node is where the Moon enters the southern ecliptic hemisphere. Motion The line of nodes, which is also the intersection between the two respective planes, rotates (precesses) with a period of 18.6 years or 19.35° per year. When viewed from the celestial north, the nodes move clockwise around Earth, I.e. with a retrograde motion (opposite to Earth's own spin and its revolution around the Sun). So the time from one node crossing to the next (see eclipse season) is approximately a half-year minus half of 19.1 days -- or about 173 days. Because the orbital plane of the Moon precesses in space, the lunar nodes also precess around the ecliptic, completing one revolution (called a ''draconic period' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lunar Eclipse Diagram-en
Lunar most commonly means "of or relating to the Moon". Lunar may also refer to: Arts and entertainment * Lunar (series), ''Lunar'' (series), a series of video games * Lunar (song), "Lunar" (song), by David Guetta * "Lunar", a song by Priestess from the 2009 album ''Prior to the Fire'' * Lunar Drive-in Theatre, in Dandenong, Victoria, Australia * Lunars, a fictional race in the series ''The Lunar Chronicles'' by Marissa Meyer Other uses * Lunar dynasty, a legendary house of warrior–rulers in ancient Indian texts * Lunar Magic, Super Mario World level editor * Lunar Design, or LUNAR, a San Francisco-based design consultancy * Hasselblad Lunar, a digital camera * Lunar, a brandname of Ethinylestradiol/cyproterone acetate, a birth control pill * Lunar C (Jake Brook, born 1990), English rapper * LUNAR (software) (1970–1972), question-answering system by Bill Woods (computer scientist) See also * * * Lunar calendar, based upon the monthly cycles of the Moon's phase ** Lunar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fixed Stars
In astronomy, the fixed stars () are the luminary points, mainly stars, that appear not to move relative to one another against the darkness of the night sky in the background. This is in contrast to those lights visible to the naked eye, namely the planets and comets, which appear to move slowly among those "fixed" stars. The fixed stars include all the stars visible to the naked eye other than the Sun, as well as the faint band of the Milky Way. Due to their star-like appearance when viewed with the naked eye, the few visible individual nebulae and other deep-sky objects are also counted among the fixed stars. Approximately 6,000 stars are visible to the naked eye under optimal conditions. The term ''fixed stars'' is a misnomer because those celestial objects are not actually fixed with respect to one another or to Earth. Due to their immense distance from Earth, these objects appear to move so slowly in the sky that the change in their relative positions is nearly imperce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astronomicum Caesareum (1540)
''Astronomicum Caesareum'' (''Astronomy of the Caesars''; also translated as ''The Emperor's Astronomy'') is a book by Petrus Apianus first published in 1540. ''Astronomicum'' was initially published in 1540. Charles V, Holy Roman Emperor, and his brother Ferdinand I, Holy Roman Emperor, both commissioned the work. It was printed at Apianus's press in Ingolstadt, Bavaria, and took eight years to produce. It expanded and changed when reprinted; the final version has 55 leaves. Apianus evidently changed his plans while producing a single edition. A volvelle in one version of ''Astronomicum'' has "an entirely irrelevant base of an astrolabe" underneath, suggesting that he considered creating one and then abandoned the idea. Twenty-one of its 36 woodcuts are volvelles. ''Astronomicum'' volvelles rely on a geocentric model of the universe. However, despite the false science on which they depended, knowledgeable readers could still use them to predict planetary movements. Ni ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solar Eclipse Of March 9, 2016
A total solar eclipse occurred at the Moon's descending node of orbit between Tuesday, March 8 and Wednesday, March 9, 2016, with a magnitude of 1.045. A total solar eclipse occurs when the Moon's apparent diameter is larger than the Sun's and the apparent path of the Sun and Moon intersect, blocking all direct sunlight and turning daylight into darkness; the Sun appears to be black with a halo around it. Totality occurs in a narrow path across Earth's surface, with the partial solar eclipse visible over a surrounding region thousands of kilometres wide. Occurring about 1.25 days before perigee (on March 10, 2016, at 7:00 UTC), the Moon's apparent diameter was larger. Totality was visible from parts of Indonesia, Micronesia, and the Marshall Islands. A partial eclipse was visible for parts of Southeast Asia, East Asia, Alaska, northwestern Australia, and Hawaii. If viewed from east of the International Date Line (for instance from Hawaii), the eclipse took place on March 8 (Tuesday ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tropical Year
A tropical year or solar year (or tropical period) is the time that the Sun takes to return to the same position in the sky – as viewed from the Earth or another celestial body of the Solar System – thus completing a full cycle of astronomical seasons. For example, it is the time from vernal equinox to the next vernal equinox, or from summer solstice to the next summer solstice. It is the type of year used by tropical solar calendars. The tropical year is one type of astronomical year and particular orbital period. Another type is the sidereal year (or sidereal orbital period), which is the time it takes Earth to complete one full orbit around the Sun as measured with respect to the fixed stars, resulting in a duration of 20 minutes longer than the tropical year, because of the precession of the equinoxes. Since antiquity, astronomers have progressively refined the definition of the tropical year. The entry for "year, tropical" in the '' Astronomical Almanac Onlin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eclipse
An eclipse is an astronomical event which occurs when an astronomical object or spacecraft is temporarily obscured, by passing into the shadow of another body or by having another body pass between it and the viewer. This alignment of three celestial objects is known as a ''syzygy''. An eclipse is the result of either an '' occultation'' (completely hidden) or a ''transit'' (partially hidden). A "deep eclipse" (or "deep occultation") is when a small astronomical object is behind a bigger one. "What is a deep eclipse? The smaller star is behind the bigger star" The term ''eclipse'' is most often used to describe either a solar eclipse, when the Moon's shadow crosses the Earth's surface, or a lunar eclipse, when the Moon moves into the Earth's shadow. However, it can also refer to such events beyond the Earth–Moon system: for example, a planet moving into the shadow cast by one of its moons, a moon passing into the shadow cast by its host planet, or a moon passing into the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gregorian Year
Gregorian may refer to: *The thought or ideology of Pope Gregory I or Pope Gregory VII (also called ''Gregorianism'') *Things named for Pope Gregory I: **Gregorian chant, the central tradition of Western plainchant, a form of monophonic, unaccompanied sacred song of the western Roman Catholic Church ** Gregorian mass **Brotherhood of Saint Gregory, a community of friars within the Anglican Communion. The community's members, known as "Gregorians", include clergy and laymen. Since 1987 there has also been a parallel order of sisters, the Sisters of Saint Gregory **Gregorian Antiphonary, an early Christian antiphonary, i.e. book of choral music to be sung antiphonally in services; it is associated traditionally with Pope Gregory I **Gregorian Sacramentary, a 10th-century illuminated Latin manuscript containing a sacramentary. Since the 16th century it has been in the Vatican Library as ''Lat. 3806'' *Things named for Pope Gregory VII: **The Gregorian Reform, a series of reforms initia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Draconic Year
A year is a unit of time based on how long it takes the Earth to orbit the Sun. In scientific use, the tropical year (approximately 365 solar days, 5 hours, 48 minutes, 45 seconds) and the sidereal year (about 20 minutes longer) are more exact. The modern calendar year, as reckoned according to the Gregorian calendar, approximates the tropical year by using a system of leap years. The term 'year' is also used to indicate other periods of roughly similar duration, such as the lunar year (a roughly 354-day cycle of twelve of the Moon's phasessee lunar calendar), as well as periods loosely associated with the calendar or astronomical year, such as the seasonal year, the fiscal year, the academic year, etc. Due to the Earth's axial tilt, the course of a year sees the passing of the seasons, marked by changes in weather, the hours of daylight, and, consequently, vegetation and soil fertility. In temperate and subpolar regions around the planet, four seasons are generally recogn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solar Eclipse Of July 31, 2000
A partial solar eclipse occurred at the Moon’s ascending node of orbit between Sunday, July 30 and Monday, July 31, 2000, with a magnitude of 0.6034. A solar eclipse occurs when the Moon passes between Earth and the Sun, thereby totally or partly obscuring the image of the Sun for a viewer on Earth. A partial solar eclipse occurs in the polar regions of the Earth when the center of the Moon's shadow misses the Earth. This was the third of four partial solar eclipses in 2000, with the others occurring on February 5, July 1, and December 25. A partial eclipse was visible for parts of northern Russia, northeastern Scandinavia, Alaska, western Canada, Greenland, and the western United States. Images Eclipse details Shown below are two tables displaying details about this particular solar eclipse. The first table outlines times at which the moon's penumbra or umbra attains the specific parameter, and the second table describes various other parameters pertaining to this eclips ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solar Eclipse Of July 1, 2000
A partial solar eclipse occurred at the Moon’s ascending node of orbit on Saturday, July 1, 2000, with a magnitude of 0.4768. A solar eclipse occurs when the Moon passes between Earth and the Sun, thereby totally or partly obscuring the image of the Sun for a viewer on Earth. A partial solar eclipse occurs in the polar regions of the Earth when the center of the Moon's shadow misses the Earth. This was the second of four partial solar eclipses in 2000, with the others occurring on February 5, July 31, and December 25. A partial eclipse was visible for parts of extreme southern South America near sunset. Images Eclipse details Shown below are two tables displaying details about this particular solar eclipse. The first table outlines times at which the moon's penumbra or umbra attains the specific parameter, and the second table describes various other parameters pertaining to this eclipse. Eclipse season This eclipse is part of an eclipse season, a period, roughl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
New Moon
In astronomy, the new moon is the first lunar phase, when the Moon and Sun have the same ecliptic longitude. At this phase, the lunar disk is not visible to the naked eye, except when it is silhouetted against the Sun during a solar eclipse. The original meaning of the term 'new moon', which is still sometimes used in calendrical, non-astronomical contexts, is the first visible crescent of the Moon after conjunction with the Sun. This thin waxing crescent is briefly and faintly visible as the Moon gets lower in the western sky after sunset. The precise time and even the date of the appearance of the new moon by this definition will be influenced by the geographical location of the observer. The first crescent marks the beginning of the month in the Islamic calendar and in some lunisolar calendars such as the Hebrew calendar. In the Chinese calendar, the beginning of the month is marked by the last visible crescent of a waning Moon. The astronomical new moon occurs by def ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solar Eclipse
A solar eclipse occurs when the Moon passes between Earth and the Sun, thereby obscuring the view of the Sun from a small part of Earth, totally or partially. Such an alignment occurs approximately every six months, during the eclipse season in its new moon phase, when the Moon's orbital plane is closest to Ecliptic, the plane of Earth's orbit. In a total eclipse, the disk of the Sun is fully obscured by the Moon. In #Types, partial and annular eclipses, only part of the Sun is obscured. Unlike a lunar eclipse, which may be viewed from anywhere on the night side of Earth, a solar eclipse can only be viewed from a relatively small area of the world. As such, although total solar eclipses occur somewhere on Earth every 18 months on average, they recur at any given place only once every 360 to 410 years. If the Moon were in a perfectly circular orbit and in the same orbital plane as Earth, there would be total solar eclipses once a month, at every new moon. Instead, because the Mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
