A solar eclipse overview

A total solar eclipse

Width is 400 times more than the moon, the sun is 400 times as far from the earth.Because of symmetry, the moon's shadow, which is on the surface of the earth's shadow, the width can cover the sun.Sunlight is completely cover the moon, bright sun disc was originally black shadow of the moon.There are, however, is only possible with the naked eye in the total solar eclipse occurs to the fuzzy of the corona.A total solar eclipse occurs when the moon is located in the perigee, only this time the moon's umbra a month to the distance between the length of the cone and umbra cone to sweep up the earth's surface.Due to the actual volume of the sun is much bigger than the moon, so the total solar eclipse usually only seen in a very small area on the earth, because the moon's umbra for the sun is just a small point.(seen in the area, the phase of an eclipse is partial eclipse).

A partial solar eclipse

Said in the history of Chinese history, there is food, not such as hook ", because of the cause of a partial solar eclipse observer in penumbra area falls on the moon, the observer will see a part of the sun is covered with the shadow of the moon, but another part of the continued to flourish.The sun and the moon only partially overlap, on the basis of both depending on the distance to the center of the (maximum diameter of the sun by the moon cover) to measure the size of the food.Partial solar eclipse is usually accompanied by other phase of an eclipse occurs, such as a total solar eclipse or an annular eclipse or full annular eclipse.But some solar eclipse in the polar regions will be pure partial (not accompanied by other phase of an eclipse), that's because the moon and the ecliptic plane is a bit far, only the penumbra touched the surface of the earth.

An annular eclipse

When the moon is at the apogee, the moon's umbra cone cannot reach the earth;To reach earth is extended out from the umbra pseudo-benying cone.At this time the moon's apparent diameter slightly smaller than the sun.Therefore, when the sun on the edge of the ball is still visible, forming a bright ring around in the shadow of the moon.(seen in the annular eclipse, the phase of an eclipse is partial eclipse).

The annular eclipse

The annular eclipse occurs only at the surface of the earth and the moon benying tip is very close, and the distance from the surface of the earth or the moon and the moon benying length is very close to the situation.Due to the earth as a sphere of relationships, and umbra shadow cone in contact with the earth as a total solar eclipse (often is in the middle of the feed belt), the food with both ends by shadow cone failed to contact with the earth, to have only pseudo-benying reach the earth, can see is an annular eclipse.So when the annular eclipse occurs, along with the relative movement between the to the moon will appear successively the annular eclipse - totality - annular eclipse, of course, for a particular site, during a solar eclipse is not at the same time see the totality and annular eclipse.The annular eclipse occurrence probability.

Solar eclipse, lunar eclipse is a typical example of light propagation along a straight line in the heavenly bodies.The moon moves between the sun and the earth is not happen every time a solar eclipse, lunar eclipse needs to meet two conditions.First, the solar eclipse happen when ShuoRi (lunar month).Not all ShuoRi must be a solar eclipse occurs, because the moon's orbit (white) and the earth's orbit (the zodiac) are not in a plane.The white plane and the ecliptic plane has 9 '5 ° Angle.Secondly, both the sun and the moon moves to Bai Daohe near the intersection of the ecliptic, the sun from the intersection point has a certain Angle (solar eclipse limit).

Due to the moon, the earth's orbit is not a perfect circle, day, month, with the distance between the earth near far, so the light from the sun by the moon covered the shadow of the formation, on the earth can be divided into the umbra, pseudo-benying (formed when the moon is farther from earth) and the penumbra.Within the scope of the observer in the umbra can see a total solar eclipse;Within the scope of the pseudo-benying can see an annular eclipse;And within the scope of the penumbra can only see a partial eclipse.

There are many mountains on the surface of the moon, the moon is not neat edge.In both fresh or raw light coming moment on the edge of the valley failed to completely cover the sun, the moon does not cover the parts form a light emitting area, like a glittering and translucent "diamond";Reddish aperture constitute a diamond ring around the "ring", as a whole, like a diamond ring decorated with bright gems, called "diamond ring".Sometimes forming many special bright light or light, as if with a string of pearls around the sun, known as "pearl" bailey (bailey is French astronomer).

Whether it is a partial solar eclipse, total solar eclipse or annular, time is very short.Of the solar eclipse can be seen on earth area is limited, this is because the moon is smaller, the umbra is small and short, thus benying sweep range on earth, time is not long, because the moon benying (373293 km) is less than the average length of the average distance between the moon and the earth (384400 km), in terms of the whole earth, the number of an annular eclipse occurs more than the total solar eclipse.

A solar eclipse phase of an eclipse

Total solar eclipse occurs, the surface with the sun round full moon surface, can be divided into five kinds of food, like:

1. The first contact.The moon than the sun's apparent motion walk fast.A solar eclipse when the moon catch up with the sun.Edges with the sun just east of the moon phase called "contact" first contact, is the first time "cut", is the beginning of the solar eclipse.

2. Both fresh.About an hour after the first contact, the eastern edge of the moon and the sun in the east marginal facies "cut inside" moment called both fresh, is the beginning of totality (or annular eclipse), for a total solar eclipse at this time the whole covering the sun, the moon for annular eclipse when the sun began to form a ring;Eclipse of the sun, the moon shadows and the sun round cut inside for the first time the location of the relationship between the two, also refers to this position relationship takes time.

Both fresh occurs after the first contact.Starting from the first contact, and the moon to run east, the sun round surface were part of the moon hide gradually increase, the intensity of the sun with a significant reduction in the heat.The month the east edge of the Japanese east edge cut inside phase, called both fresh.The direction and map in the opposite direction.

3. Very fresh.The sun is the deepest moments, the moon's center moved to the nearest center with the sun;In the process of the partial solar eclipse, the sun by the moon covered the most time, the position relationship between the two;In the process of total solar eclipse and annular eclipse the sun be covered entirely by the moon and two nearest center, the position relationship between the two.Also refers to the position relations.

4. Light.West edge of the moon and the sun west edge "cut in" moment of light, is the end of the total solar eclipse;From both fresh to light usually only two or three minutes, the longest not more than seven and a half.

For the solar eclipse, very fresh, the moon relative surface moved to the east.

5. The last contact.Light after about an hour, the west edge of the moon and the sun in the east marginal facies "contact" is called the last contact, since then the moon completely "out of" the sun, the solar eclipse is over.

Total solar eclipse and annular eclipse had the five process, and a partial solar eclipse only first contact, very fresh, fourth contact three process, not both fresh, light.

Summary of the eclipse

Lunar eclipse may divide into the partial lunar eclipse, total lunar eclipse, and three kinds of penumbral lunar eclipse.When the moon only partially enters earth's umbra, partial lunar eclipse will occur.And the diameter of the earth's umbra is equivalent to 2.5 times of the moon.So the center of the earth and the moon is roughly in the same straight line, the moon will be fully into the earth's umbra, and produce a total eclipse of the moon.And if the moon benying only part is always the earth cover, that is only part of the earth's umbra, partial lunar eclipse.The moon will not appear YueHuanShi.Because, the volume of the moon is smaller than the earth in the earth's umbra, so won't appear on annular eclipse of the phenomenon.Eclipse number is generally 2 times a year, most happened three times, sometimes, it doesn't happen again.Because in general, the moon is not from the top of the earth's umbra, is gone, below rarely through the part or by the earth's umbra, so in general the eclipse will happen., according to the observation data in each century penumbral lunar eclipse, the partial lunar eclipse, the percentage of the total eclipse occurred at about 36.60%, 34.46% and 28.94%.

The eclipse phase of an eclipse

1. Changing the beginning: the moon just contact and the penumbra area, when the moon's surface luminosity slightly less, but more difficult to perceive to the naked eye.

2. The first contact (partial lunar eclipse and the eclipse only) : eclipse began.From east edge slowly into the shadow on the moon, the moon and the earth's umbra cut for the first time.

3. Both fresh (total eclipse) only: the moon enters the earth's umbra, and with the umbra cut inside for the first time.The moon just all into the earth's umbra.

4. Very fresh: the moon surface center and the center of the earth's umbra closest to the moment, at this time the moon's surface before and after a copper or dark red.(reason: is refracted through earth's atmosphere occurred, make the light bend inward, but each is not the same as the degree of bending (dispersion) of light, red light bending degree of the largest, the most close to the earth's shadow, reflected on the moon.In addition, because of the dust in the atmosphere and the content of cloud and position is different, the light bending degree will have different, so the total eclipse of the moon is dark red, red, or orange.In the same way, because of the atmosphere refraction, sunrise and the sunset is not white, and according to different height because the degree of atmospheric refraction, orange or red.)

5. Light (total eclipse) only: the moon benying earth in moving, and within the earth's umbra and the second cut.East edge of the moon with the earth's umbra east edge cut inside, then end of the total eclipse phase.

6. Last contact (only partial lunar eclipse and eclipse) : the moon gradually away from the earth's umbra, and earth's umbra second circumscribed.East west edge of the moon with the earth's umbra marginal facies cut, then a lunar eclipse whole process over.The moon was food degree is called "The Times", it is equal to its month edge into the earth and the moon benying longest distance between the ratio of the.

7. The changing end: the moon left the penumbra, the entire eclipse officially over.Partial lunar eclipse without both fresh, light process, its also said that only the most close to the earth's shadow.(The zodiac /astro/)

The size of the degree of the eclipse by times.Times is equal to its maximum, depending on the diameter of the moon in its part of the umbra and depending on the ratio of the diameter of the moon.Its just like the moon benying and cut inside, times is equal to 1.Its like the moon more deep umbra, expressed in Numbers greater than 1 times.The total times greater than or equal to 1.Certain times are less than 1.Times of penumbral lunar eclipse with the moon part into the penumbra in diameter and diameter of the moon as ratios.Penumbral lunar eclipse times greater than 0.7, the naked eye can perceive.