Yunnan Observatory Expert Interprets Astronomical Science Knowledge

At 9:00 a.m., Prof. Gao, expert from Yunnan Observatory, Chinese Academy of Sciences interpreted astronomical science, especially the formation of solar and lunar eclipses, to National Middle School students.
Total solar eclipse occurs only when the moon passes between the sun and the earth and the three celestial bodies come exactly in a straight line, or at least very close to it, so that the Sun is fully covered. Total solar eclipses are nevertheless rare at any location because during each eclipse totality exists only along a narrow corridor in the relatively tiny area of the Moon's umbra.It may happen only once in 3-4 hundred years on average at one area, and the time for the sun being completely covered is no longer than 7 minutes and 41 seconds.
Prof.. Gao reminded students again and again to keep away from staring at the sun with naked eyes, because the sun emits infrared and ultraviolet lights as well as a strong visible light. UV not only sunburns the skins, it also damages the retina of eyes. Looking directly at the sun may result in permanent injury to your eyes, or even blindness. Observing the sun through telescope lack of adequate optical equipment will bring up dreadful consequences. Therefore, to avoid possible damages, the total solar eclipse observation must be done with the help of equipments for special usage; and never think of doing it with naked eyes.

Prof. Gao explains the different sizes of Sun and Moon by comparing them to pan lid and teacup.