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Umbra, Penumbra, And Antumbra
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 the Earth, totally or partially. Such an alignment occurs during an eclipse season, approximately every six months, during the new moon phase, when the Moon's orbital plane is closest to the plane of the Earth's orbit. In a total eclipse, the disk of the Sun is fully obscured by the Moon. In 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 Moon's ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solar Eclipse 1999 4
Solar may refer to: Astronomy * Of or relating to the Sun ** Solar telescope, a special purpose telescope used to observe the Sun ** A device that utilizes solar energy (e.g. "solar panels") ** Solar calendar, a calendar whose dates indicate the position of the Earth on its revolution around the Sun * Solar Maximum Mission, a satellite * SOLAR (ISS), an observatory on International Space Station Music * Solar (composition), "Solar" (composition), attributed to Miles Davis * Solar (Red Garland album), ''Solar'' (Red Garland album), 1962 * Solar (Taeyang album), ''Solar'' (Taeyang album), 2010 * ''Solar'', a 2011 album by Rubik (band), Rubik * "Solar", a song by Northlane from ''Mesmer (Northlane album), Mesmer'', 2017 * SOLAR Records, a record label Geography * Solar (Spanish term), a type of urban site * Solar, County Antrim, Northern Ireland, United Kingdom * Solar, Erode, India * Solar, Iran, Iran Companies * Solar Entertainment Corporation, a Philippines television ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inclination
Orbital inclination measures the tilt of an object's orbit around a celestial body. It is expressed as the angle between a Plane of reference, reference plane and the orbital plane or Axis of rotation, axis of direction of the orbiting object. For a satellite orbiting the Earth directly above the Equator, the plane of the satellite's orbit is the same as the Earth's equatorial plane, and the satellite's orbital inclination is 0°. The general case for a circular orbit is that it is tilted, spending half an orbit over the northern hemisphere and half over the southern. If the orbit swung between 20° north latitude and 20° south latitude, then its orbital inclination would be 20°. Orbits The inclination is one of the six orbital elements describing the shape and orientation of a celestial orbit. It is the angle between the orbital plane and the plane of reference, normally stated in degree (angle), degrees. For a satellite orbiting a planet, the plane of reference is usually ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Comparison Angular Diameter
Comparison or comparing is the act of evaluating two or more things by determining the relevant, comparable characteristics of each thing, and then determining which characteristics of each are similar to the other, which are different, and to what degree. Where characteristics are different, the differences may then be evaluated to determine which thing is best suited for a particular purpose. The description of similarities and differences found between the two things is also called a comparison. Comparison can take many distinct forms, varying by field: To compare things, they must have characteristics that are similar enough in relevant ways to merit comparison. If two things are too different to compare in a useful way, an attempt to compare them is colloquially referred to in English as "comparing apples and oranges." Comparison is widely used in society, in science and in the arts. General usage Comparison is a natural activity, which even animals engage in when deci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Civil Twilight
Twilight is light produced by sunlight scattering in the upper atmosphere, when the Sun is below the horizon, which illuminates the lower atmosphere and the Earth's surface. The word twilight can also refer to the periods of time when this illumination occurs. The lower the Sun is beneath the horizon, the dimmer the twilight (other factors such as atmospheric conditions being equal). When the Sun reaches 18° below the horizon, the twilight's brightness is nearly zero, and evening twilight becomes nighttime. When the Sun again reaches 18° below the horizon, nighttime becomes morning twilight. Owing to its distinctive quality, primarily the absence of shadows and the appearance of objects silhouetted against the lit sky, twilight has long been popular with photographers and painters, who often refer to it as the blue hour, after the French expression ''l'heure bleue''. By analogy with evening twilight, the word ''twilight'' is also sometimes used metaphorically, to imply t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Umbra
The umbra, penumbra and antumbra are three distinct parts of a shadow, created by any light source after impinging on an opaque object. Assuming no diffraction, for a collimated beam (such as a point source) of light, only the umbra is cast. These names are most often used for the shadows cast by celestial bodies, though they are sometimes used to describe levels, such as in sunspots. Umbra The umbra (Latin for "shadow") is the innermost and darkest part of a shadow, where the light source is completely blocked by the occluding body. An observer within the umbra experiences a total eclipse. The umbra of a round body occluding a round light source forms a right circular cone. When viewed from the cone's apex, the two bodies appear the same size. The distance from the Moon to the apex of its umbra is roughly equal to that between the Moon and Earth: . Since Earth's diameter is 3.7 times the Moon's, its umbra extends correspondingly farther: roughly . Penumbra The pe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Annulus (mathematics)
In mathematics, an annulus (plural annuli or annuluses) is the region between two concentric circles. Informally, it is shaped like a ring or a hardware washer. The word "annulus" is borrowed from the Latin word ''anulus'' or ''annulus'' meaning 'little ring'. The adjectival form is annular (as in annular eclipse). The open annulus is topologically equivalent to both the open cylinder and the punctured plane. Area The area of an annulus is the difference in the areas of the larger circle of radius and the smaller one of radius : :A = \pi R^2 - \pi r^2 = \pi\left(R^2 - r^2\right). The area of an annulus is determined by the length of the longest line segment within the annulus, which is the chord tangent to the inner circle, in the accompanying diagram. That can be shown using the Pythagorean theorem since this line is tangent to the smaller circle and perpendicular to its radius at that point, so and are sides of a right-angled triangle with hypotenuse , and the ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solar Eclipse May 20,2012
Solar may refer to: Astronomy * Of or relating to the Sun ** Solar telescope, a special purpose telescope used to observe the Sun ** A device that utilizes solar energy (e.g. "solar panels") ** Solar calendar, a calendar whose dates indicate the position of the Earth on its revolution around the Sun * Solar Maximum Mission, a satellite * SOLAR (ISS), an observatory on International Space Station Music * "Solar" (composition), attributed to Miles Davis * ''Solar'' (Red Garland album), 1962 * ''Solar'' (Taeyang album), 2010 * ''Solar'', a 2011 album by Rubik * "Solar", a song by Northlane from ''Mesmer'', 2017 * SOLAR Records, a record label Geography * Solar (Spanish term), a type of urban site * Solar, County Antrim, Northern Ireland, United Kingdom * Solar, Erode, India * Solar, Iran, Iran Companies * Solar Entertainment Corporation, a Philippines television and radio media company * Solar TV, a former TV channel * Solar Television Network, Inc., a former name o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Occultation Symbol
An occultation is an event that occurs when one object is hidden from the observer by another object that passes between them. The term is often used in astronomy, but can also refer to any situation in which an object in the foreground blocks from view (occults) an object in the background. In this general sense, occultation applies to the visual scene observed from low-flying aircraft (or computer-generated imagery) when foreground objects obscure distant objects dynamically, as the scene changes over time. If the closer body does not entirely conceal the farther one, the event is called a ''transit''. Both transit and occultation may be referred to generally as ''occlusion''; and if a shadow is cast onto the observer, it is called an eclipse. The symbol for an occultation, and especially a solar eclipse, is file:Occultation symbol.svg (U+1F775 🝵). Occultations by the Moon The term occultation is most frequently used to describe lunar occultations, those relatively ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eclipse Chasing
Eclipse chasing is the pursuit of observing solar eclipses when they occur around the Earth. Solar eclipses must occur at least twice and as often as five times a year across the Earth. Total eclipses may occur multiple times every few years. A person who chases eclipses is known as a umbraphile, meaning shadow lover. Umbraphiles often travel for eclipses and use various tools to help view the sun including solar viewers also known as eclipse glasses, as well as telescopes. The solar eclipse of March 29, 2006, is an example for an eclipse that many people around the world chased it, when traveling to areas where it was visible as a total eclipse. As of 2017, three New Yorkers, Glenn Schneider, Jay Pasachoff, and John Beattie have each seen 33 total solar eclipses, the current record. Donald Liebenberg, professor of astronomy at Clemson University in South Carolina has seen 26 traveling to Turkey, Zambia, China, the Cook Islands and others. History In the 19th century, Mabel Lo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sungazing
Sungazing is the dangerous practice of looking directly into the Sun. It is sometimes done as part of a spiritual or religious practice, most often near dawn or dusk. The human eye is very sensitive, and exposure to direct sunlight can lead to solar retinopathy, pterygium, cataracts, and often blindness. Studies have shown that even when viewing a solar eclipse the eye can still be exposed to harmful levels of ultraviolet radiation. Movements Referred to as ''sunning'' by William Horatio Bates as one of a series of exercises included in his Bates method, it became a popular form of alternative therapy in the early 20th century. His methods were widely debated at the time but ultimately discredited for lack of scientific rigor. The ''British Medical Journal'' reported in 1967 that "Bates (1920) advocated prolonged sun-gazing as the treatment of myopia, with disastrous results". See also * Inedia (breatharianism) * Joseph Plateau * Scientific skepticism Scientific skepticis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Omen
An omen (also called ''portent'') is a phenomenon that is believed to foretell the future, often signifying the advent of change. It was commonly believed in ancient times, and still believed by some today, that omens bring divine messages from the gods. These omens include natural phenomena, for example an eclipse, abnormal births of animals (especially humans) and behaviour of the sacrificial lamb on its way to the slaughter. Specialists, known as diviners, variously existed to interpret these omens. They would also use an artificial method, for example, a clay model of a sheep liver, to communicate with their gods in times of crisis. They would expect a binary answer, either yes or no, favourable or unfavourable. They did these to predict what would happen in the future and to take action to avoid disaster. Though the word ''omen'' is usually devoid of reference to the change's nature, hence being possibly either "good" or "bad", the term is more often used in a forebodin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Supernatural
Supernatural refers to phenomena or entities that are beyond the laws of nature. The term is derived from Medieval Latin , from Latin (above, beyond, or outside of) + (nature) Though the corollary term "nature", has had multiple meanings since the ancient world, the term "supernatural" emerged in the Middle Ages and did not exist in the ancient world. The supernatural is featured in folklore and religious contexts, but can also feature as an explanation in more secular contexts, as in the cases of superstitions or belief in the paranormal. The term is attributed to non-physical entities, such as angels, demons, gods, and spirits. It also includes claimed abilities embodied in or provided by such beings, including magic, telekinesis, levitation, precognition, and extrasensory perception. The philosophy of naturalism contends that nothing exists beyond the natural world, and as such approaches supernatural claims with skepticism. Etymology and history of the concept Occurr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
