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Exhibition Guide

The Earth

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Purpose of Exhibition


Celestial objects and various information on astronomy subjects are displayed on the perimeter of this exhibition room. Walking alongside the wall clockwisely, we can travel through the scale of the universe starting from the earth to the edge of the universe.
The first scale is "The Earth". In this exhibition, you can see the images of the Earth and the Moon on a large screen, as well as the magnetosphere, aurora and the type and origin of meteorites and shooting stars.

Additional Knowledge


[The Real Number of Shooting Stars]
During the meteor showers, you can see many more shooting stars than on the usual nights. However, this does not mean you will be able to see stars going across one after the other. Throughout the year, the most active meteor showers are the Perseids, in mid-August, and the Geminids, in mid-December. These two meteor showers become active every year steadily.
Now, let’s count the number of shooting stars in these cases. To do so, it is necessary to normalize the conditions in order to add and compare the number of meteor showers over several years. Ideally, the revised number of meteor showers is described as "ZHR" (Zenith Hourly Rate). This observation is conducted as follows: First, the sky must be clear for at least one hour. Second, the chosen location should be dark enough for the Milky Way to be visible and to have a good view of the starry sky. Third, the radiant of the meteor shower should be exactly at the zenith. Finally, the condition should be such that you can count any shooting star, including dark and subtle ones. This is the ideal condition for counting meteors, which is not able to fully satisfy. Although this method is essential for a comparative study, you should not think that this counting record is equal to the real number of visible shooting stars. In most cases, there is a cloud covererage, and also the Milky Way is not visible. In other cases, we can see stars before or after the radiant point rises at the zenith. Finally, there is a possibility of counting loss. So, even if you go to the mountain or the ocean where you can clearly see the starry sky, the possibility of encountering shooting stars is likely to be less than half of ZHR.
Furthermore, the record of the number of meteor per hour might also be confusing.
Let’s put it another way.
On the night of a meteor shower, let’s think of it as a night when we can see rare meteors, and not a night when many meteors will cross one after another. Very bright meteors can be easily seen not only from the mountains but also from a town. The night when you are likely to encounter such memorable meteor must be a night of meteor showers. Why not try stay up late for such a special night?

 


【 References 】

Article by Astronomy Section

 

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