Total Solar Eclipse Practice Report

The process of a total solar eclipse can include the following five periods: initial loss, eclipse, eclipse, light, and fullness.

First Waning Since the moon orbits the earth from west to east, a solar eclipse always starts on the western edge of the sun's disk. The moment when the east edge of the moon just touches the disk of the sun (that is, the moment when the east edge of the moon is tangent to the west edge of the moon), it is called first waning. The initial loss is the moment when the eclipse process begins.

Since eclipse starts from the initial loss, it is the partial eclipse stage. As the moon continues to move eastward, the portion of the sun's disc obscured by the moon gradually increases, and the intensity and heat of the sun decreases significantly. When the eastern edge of the moon is inscribed with the eastern edge of the sun, it is called an eclipse. At this time, the entire solar disk is covered, so the eclipse is also the moment when the total solar eclipse begins.

When the sun is about to be completely blocked by the moon, an arc of diamond-like light will suddenly appear on the eastern edge of the sun, just like the eye-catching shining light on a diamond ring. This is the diamond ring. At the same time, In an instant, they form a string of luminous bright spots, like a string of dazzling pearls hanging high in the dark sky. This phenomenon is called pearl eclipse. The British astronomer Bailey first described this phenomenon, so it is also called Beads. This is because there are many rugged peaks on the moon's surface. When sunlight hits the edge of the moon, the bead phenomenon is formed. The bead appears for a very short time, usually only one or two seconds, and then the sun's rays are completely blocked and a total solar eclipse occurs.

During a total solar eclipse, the earth becomes dark and the animals return to their lairs in fright. At this time, a wonderful scene will appear in the sky: bright stars will come out, and where the sun used to be, only the dark moon will be seen, with a beautiful, light red glow around it. This is the chromosphere of the sun; outside the chromosphere there is a silvery white or light blue light, which is the outer atmosphere of the sun - the corona; in some areas of the light red chromosphere, you can also see See some flame-like clouds erupting upward, which are solar prominences. Solar prominences are gas "fountains" formed by violent movement of gas in the upper part of the chromosphere. The chromosphere, solar bait, and corona are all components of the sun's outer atmosphere. They can be observed under certain conditions in normal times, but during a total solar eclipse, these phenomena can be seen particularly clearly.

After the light eclipse, the moon wheel continues to move eastward. When the center of the moon wheel and the center of the sun are closest to each other, the eclipse is reached. For a partial solar eclipse, the eclipse is the time when the sun is most obscured by the moon. The moon continues to move eastward, and the moment when the western edge of the moon is inscribed with the western edge of the sun is called luminescence, which is the moment when the total solar eclipse ends. Before the luminescence occurs, the phenomena of diamond rings and beads will appear at the western edge of the sun, but they will disappear soon. Then another dazzling ray of light shot out from the western edge of the sun. The chromosphere, prominences, corona and other phenomena that could be seen during the total solar eclipse were quickly hidden in the sunlight, the stars also disappeared, and the sunlight returned to the earth.

After completing the circle and generating light, the moon continues to move away from the sun, and the part of the sun that is blocked gradually decreases. The moment when the western edge of the moon is tangent to the east edge of the sun is called a complex circle. At this time, the sun takes on a disk shape again, and the entire solar eclipse process comes to an end.

The process of a partial solar eclipse is roughly the same as the process of a total solar eclipse. Since it only occurs a partial eclipse, there are only initial waning, eclipse and re-eclipse, but there are no two stages: eclipse and light generation. An annular solar eclipse also has stages such as initial loss, eclipse, eclipse, light generation, and full circle.

When the observatory forecasts a total solar eclipse or an annular solar eclipse, it often reports the times of these five stages. Based on these reports, people can understand the entire solar eclipse process and make observations. As for a partial solar eclipse, when forecasting, of course the observatory only gives three moments: initial waning, full eclipse, and full eclipse.

In solar eclipse forecasts, we often see the word "eclipse", which is used to indicate the extent of the solar eclipse. For a solar eclipse, the eclipse does not represent the area of ??the sun's disk that is obscured, but rather represents the ratio of the obscured portion of the sun's diameter to the diameter of the sun. Taking the diameter of the sun as 1, if the eclipse is 0.5, it means that half of the sun's diameter is covered; if the eclipse is 1, it means that the entire circular surface of the sun is covered, which is a total solar eclipse. Obviously, the greater the eclipse, the greater the extent to which the sun will be obscured. The eclipse value of a partial solar eclipse is less than 1.0, and the eclipse value of a total solar eclipse is 1.0.

The place where the moon's shadow sweeps across the eclipse belt. The length of the solar eclipse is related to the speed of the moon's shadow cone moving on the ground and the direction of the earth's rotation. In the case of a total solar eclipse, since the apparent diameter of the moon is only slightly larger than that of the sun, and the moon's shadow moves quickly on the ground, the duration of the total solar eclipse is very short. The duration of a total solar eclipse seen at a certain location in the total eclipse zone is usually only two to three minutes, and no more than 7 minutes at most. If the total eclipse belt passes near the equator, the total solar eclipse will last for 7 minutes and 40 seconds. This is the best opportunity to observe the total solar eclipse.

When an annular solar eclipse occurs, the moon is always located near the apogee. At this time, the moon moves slower, so the annular solar eclipse lasts longer. If the annular solar eclipse occurs near the equator, then the The viewing time of an annular solar eclipse near the equator can be as long as 12 minutes and 42 seconds.

On a global scale, if the time when the moon's penumbra begins to cover the sun is included, the entire process of the solar eclipse from initial waning to full circle can be as long as three and a half hours.

During a partial solar eclipse, because the moon's shadow is larger than its umbra, the length of time the eclipse passes depends on the size of the eclipse. The larger the eclipse, the longer it will take.

Because the moon's shadow cone is thin and long, when it falls on the earth's surface, it occupies a very small area, at most no more than one ten thousandth of the earth's total area. Its diameter is the largest. It’s only over 260 kilometers. When the moon rotates around the earth, the shadow cone sweeps across a relatively long area on the ground from west to east. In the area swept by the moon's shadow, the solar eclipse can be seen. So this belt is called the "solar eclipse belt". The zone where a total solar eclipse occurs is called a total eclipse zone; the zone where an annular solar eclipse occurs is called an annular eclipse zone. It can be seen that the scope of the partial eclipse is very broad. It is no longer like a belt, but a large area.

The totality belt is a narrow path with a width of only two to three hundred kilometers and a length of about thousands to 10,000 kilometers (sometimes the width of the totality belt is even only a few kilometers). Only those areas swept by the totality belt A total or annular solar eclipse can only be seen in certain areas. On both sides of the totality zone are wider penumbra-swept areas where partial eclipses are visible. The closer the partial eclipse area is to the total eclipse zone, the greater the degree of partial eclipse will be seen; the further away from the zone, the smaller the degree of partial eclipse will be visible; the solar eclipse will not be visible outside the penumbral zone.

Since the moon moves from west to east, its shadow also moves in the same direction, so the time for seeing the solar eclipse is different in different places. When the western area on the ground is already in the dark shadow area and people in this area have seen the solar eclipse, people in the eastern area cannot see the solar eclipse at the same time. They have to wait until the moon's shadow moves eastward before they can see the sun. Food. Therefore, people in the west always see the solar eclipse before people in the east.

Solar eclipses occur every year, but because the total eclipse belt is a narrow shadow belt, it is estimated that only every 200 to 300 years on average, a certain region or city has the opportunity to be swept by the total eclipse belt. , for people living in a city, they may have never seen a total solar eclipse in their lives