El eclipse anular de sol del 15 de enero de 2010

Eclipse anular de sol hoy

El fenómeno astronómico no ocultará al Sol completamente, pudiéndose ver durante el máximo del eclipse un singular anillo de luz proveniente del astro.
Durante el máximo del eclipse solar, se podrá apreciar un “anillo de fuego”, que corresponde a una porción anular del disco solar que no fue ocultada por la Luna (NASA).
Las líneas azules indican las zonas en dónde se podrá ver el eclipse en forma parcial, mientras que las rojas muestran en dónde se verá anular (NASA, F. Espenak).
Ver las imágenes en detalle…
¿Te pareció interesante esta Noticia?
1 votos
Valoración media: 7/7.
Enlaces Patrocinados
Redacción de AstronomíaHoy.
05/01/2010. Para el Viernes 15 de Enero de este año, la NASA ha predicho un eclipse de Sol, el cual podrá ser avistado desde el este de África y Europa, y en toda Asia. Desde una estrecha franja sobre la Tierra, que pasará por el centro de África, el océano Índico, el sur de la India, hasta el norte de China, se podrá observar la anularidad del fenómeno.

Técnicamente, el fenómeno comenzará a las 04:05 UT, cuando la penumbra generada por la Luna comience a cubrir a la Tierra, saliendo completamente de esta a las 10:07 UT.

Observacionalmente, lo más interesante de estos fenómenos es cuando es cuando el Sol es cubierto por la Luna (equivalentemente, cuando la Tierra entra en la sombra generada por el satélite): el inicio de esta etapa del eclipse será a las 05:14 UT, y la Tierra saldrá de la sombra a las 08:59 UT.

Para aquellos observadores que se encuentren sobre la franja de anularidad, la etapa anular del eclipse tendrá una duración máxima de 11 minutos con 8 segundos.

La NASA ha publicado una completa información acerca del eclipse, incluyendo las circunstancias locales en que podrá ser visto el fenómeno, en su sitio web (en inglés, véanse referencias).

Astronomos observando un eclipse,A.Caron (Wikipedia)

El próximo eclipse solar ocurrirá el 11 de Julio del 2010, y se podrá ver desde el sur del Océano Pacífico, todo Chile, Perú, Bolivia, Paraguay, Uruguay y Argentina.

AstronomíaHoy se encuentra preparando un sitio web especial, con toda la información para este evento astronómico.

LOS ECLIPSES EN LA HISTORIA

Existen numerosas referencias históricas de este tipo de fenómenos en distintas épocas y culturas; así constan documentados eclipses en el año 709 a. C. en China o en el 332 a. C. en Babilonia. El eclipse solar más antiguo del que existe constancia sucedió en China el 22 de octubre del año 2137 a. C., y que al parecer costó la vida a los astrónomos reales Hi y Ho, los cuales no supieron predecirlo a tiempo.

Los eclipses de Sol y Luna han representado mucho para el desarrollo científico. Fueron los griegos los que descubrieron el período Saros que les permitió predecir eclipses. Por otra parte, Aristarco de Samos (310 a. C.-230 a. C.) determinó por primera vez la distancia de la Tierra a la Luna mediante un eclipse total de Luna. Hiparco(194 a. C.-120 a. C.) descubrió la Precesión de los equinoccios basándose en eclipses lunares totales cerca de los Equinoccios y en unas tablas para el Sol, y mejoró la determinación de la distancia de la Tierra a la Luna realizada por Aristarco. Kepler propuso usar los eclipses de Luna como una señal absoluta para medir la longitud geográfica de un lugar sobre la Tierra.

Hacia 1700 los astrónomos llegan a la conclusión de que los eclipses antiguos observados por chinos, caldeos y árabes eran incompatibles con la duración del día actual. Las mareas habían alargado el día 1,45 milisegundos cada siglo y en 20 siglos el retardo acumulado es de unas 3 horas. Durante el siglo XIX se produce un gran avance en espectroscopia que permite descubrir el helio en el Sol y Einstein resuelve el enigma del excesivo avance del perihelio de Mercurio y la curvatura de la luz cerca del Sol. Los eclipses del Sol son una brillante confirmación de la Teoría de la Relatividad

LOS ECLIPSES EN LA HISTORIA (Wikipedia en ingles)

Historical eclipses

Astronomers Studying an Eclipse by Antoine Caron

Historical eclipses are a valuable resource for historians, in that they allow a few historical events to be precisely dated, from which other dates and a society’s calendar can be deduced. Aryabhata (476–550) concluded the Heliocentric theory in solar eclipse. A solar eclipse of June 15, 763 BCE mentioned in an Assyrian text is important for the Chronology of the Ancient Orient. Also known as the eclipse of Bur Sagale, it is the earliest solar eclipse mentioned in historical sources that has been successfully identified. Perhaps the earliest still-unproven claim is that of archaeologist Bruce Masse; on the basis of several ancient flood myths that mention a total solar eclipse, he links an eclipse that occurred May 10, 2807 BCE with a possible meteor impact in the Indian Ocean.^[20] There have been other claims to date earlier eclipses, notably that of Mursili II (likely 1312 BCE), in Babylonia, and also in China, during the 5th year (2084 BCE) of the regime of Emperor Zhong Kang of Xia dynasty, but these are highly disputed and rely on much supposition.^[21][22]

Herodotus wrote that Thales of Miletus predicted an eclipse which occurred during a war between the Medians and the Lydians. Soldiers on both sides put down their weapons and declared peace as a result of the eclipse. Exactly which eclipse was involved has remained uncertain, although the issue has been studied by hundreds of ancient and modern authorities. One likely candidate took place on May 28, 585 BCE, probably near the Halys river in the middle of modern Turkey.^[23]

An annular eclipse of the Sun occurred at Sardis on February 17, 478 BCE, while Xerxes was departing for his expedition against Greece, as Herodotus recorded.^[24] Hind and Chambers considered this absolute date more than a century ago.^[25] Herodotus also reports that another solar eclipse was observed in Sparta during the next year, on August 1, 477 BCE.^[26][27][28] The sky suddenly darkened in the middle of the day, well after the battles of Thermopylae and Salamis, after the departure of Mardonius to Thessaly at the beginning of the spring of (477 BCE) and his second attack on Athens, after the return of Cleombrotus to Sparta. The modern conventional dates are different by a year or two, and that these two eclipse records have been ignored so far.^[29] The Chronicle of Ireland recorded a solar eclipse on June 29, 512 CE, and a solar eclipse was reported to have taken place during the Battle of Stiklestad in July, 1030.

In the Indian epic the Mahabharata the incident is related of the 13th day when Arjun vows to slay Jayadrath before nightfall, to avenge the death of Abhimanyu at Jayadratha’s hands. What can only be described as a solar eclipse brings Jayadrath out to celebrate his surviving the day, only to have the sun reappear, and Arjun kill Jayadrath. In the epic Astronomers have calculated all possible eclipse pairs matching the above time difference and visible from Kurukshetra, the battlefield of the Mahabharata war. 3129 BCE and 2559 BCE appear to be the best candidate for the Mahabharata war ^[30]

It has also been attempted to establish the exact date of Good Friday by means of solar eclipses, but this research has not yielded conclusive results.^[31] Research has manifested the inability of total solar eclipses to serve as explanations for the recorded Good Friday features of the crucifixion eclipse.^[32] (Good Friday is recorded as being at Passover, which is also recorded as being at or near the time of a full moon.)

The ancient Chinese astronomer Shi Shen (fl. 4th century BCE) was aware of the relation of the moon in a solar eclipse, as he provided instructions in his writing to predict them by using the relative positions of the moon and sun.^[33] The ‘radiating influence’ theory for a solar eclipse (i.e., the moon’s light was merely light reflected from the sun) was existent in Chinese thought from about the 6th century BCE (in the Zhi Ran of Zhi Ni Zi),^[34] and opposed by the Chinese philosopher Wang Chong (27–97 CE), who made clear in his writing that this theory was nothing new.^[35] This can be said of Jing Fang’s writing in the 1st century BCE, which stated:

The moon and the planets are Yin; they have shape but no light. This they receive only when the sun illuminates them. The former masters regarded the sun as round like a crossbow bullet, and they thought the moon had the nature of a mirror. Some of them recognized the moon as a ball too. Those parts of the moon which the sun illuminates look bright, those parts which it does not, remain dark.^[34]

The ancient Greeks had known this as well, since it was Parmenides of Elea around 475 BCE who supported the theory of the moon shining because of reflected light, and was accepted in the time of Aristotle as well.^[34] The Chinese astronomer and inventor Zhang Heng (78–139 CE) wrote of both solar and lunar eclipses in the publication of Ling Xian in 120 CE, supporting the radiating influence theory that Wang Chong had opposed (Wade-Giles):

The sun is like fire and the moon like water. The fire gives out light and the water reflects it. Thus the moon’s brightness is produced from the radiance of the sun, and the moon’s darkness (pho) is due to (the light of) the sun being obstructed (pi). The side which faces the sun is fully lit, and the side which is away from it is dark. The planets (as well as the moon) have the nature of water and reflect light. The light pouring forth from the sun (tang jih chih chhung kuang) does not always reach the moon owing to the obstruction (pi) of the earth itself—this is called ‘an-hsü’, a lunar eclipse. When (a similar effect) happens with a planet (we call it) an occulation (hsing wei); when the moon passes across (kuo)(the sun’s path) then there is a solar eclipse (shih).^[36]

The later Chinese scientist and statesman Shen Kuo (1031–1095 CE) also wrote of eclipses, and his reasoning for why the celestial bodies were round and spherical instead of flat (Wade-Giles spelling):

The Director [of the Astronomical Observatory] asked me about the shapes of the sun and moon; whether they were like balls or (flat) fans. If they were like balls they would surely obstruct (ai) each other when they met. I replied that these celestial bodies were certainly like balls. How do we know this? By the waxing and waning (ying khuei) of the moon. The moon itself gives forth no light, but is like a ball of silver; the light is the light of the sun (reflected). When the brightness is first seen, the sun(-light passes almost) alongside, so the side only is illuminated and looks like a crescent. When the sun gradually gets further away, the light shines slanting, and the moon is full, round like a bullet. If half of a sphere is covered with (white) powder and looked at from the side, the covered part will look like a crescent; if looked at from the front, it will appear round. Thus we know that the celestial bodies are spherical…Since the sun and moon are in conjunction (ho) and in opposition (tui) once a day, why then do they have eclipses only occasionally?’ I answered that the ecliptic and the moon’s path are like two rings, lying one over the other (hsiang tieh), but distant by a small amount. (If this obliquity did not exist), the sun would be eclipsed whenever the two bodies were in conjunction, and the moon would be eclipsed whenever they were exactly in position. But (in fact) though they may occupy the same degree, the two paths are not (always) near (each other), and so naturally the bodies do not (intrude) upon one another.^[37]

Eclipses have been interpreted as omens, or portents, especially when associated with battles. On 22 January 1879 a British battalion was massacred by Zulu warriors during the Zulu War in South Africa. At 2:29 PM there was a solar eclipse.^[38] The conflict was named the Battle of Isandlwana, the Zulu name for the battle translates as “the day of the dead moon”.^[39]

Wikipedia en español: