The longest total solar eclipse of this century will occur on July 22. Although it will be visible only from a limited number of places in Japan, including Yakushima and Amami-Oshima islands in Kagoshima Prefecture, a partial eclipse will be visible around the country. According to experts, just a little effort will make it possible to enjoy the eclipse safely. However, extra care should be taken to prevent children from looking directly at the sun, as many primary and middle school students will be on summer vacation on July 22 and are likely to watch the eclipse. "This is a rare chance to see so much of the sun blocked out," 45-year-old astrophotographer Akio Nakanishi said. At its height, the partial eclipse will cover about 50 percent of the sun in Sapporo, about 75 percent in Tokyo and about 90 percent in Fukuoka. Although not as impressive as a total solar eclipse, in which the sun is entirely covered by the moon, a partial eclipse is still an impressive sight. The eclipse will be at its height at about 11 a.m. As the rays of the sun are strong, people in Tokyo will be able to observe the eclipse from about 10:40 a.m. when the sun will be about half concealed. Nakanishi recommended watching the eclipse indirectly, by standing in the shadow of a tree around this time and watching sunbeams streaming through the leaves. The small openings between the leaves will act as pinholes, causing the sunlight falling on the ground to be crescent-shaped. This phenomenon is more effectively seen on smooth surfaces than on grassy areas.
Another possibility is to catch the shifting sunbeams on a handkerchief. You can also make a small hole with a pencil or a drafting compass in a piece of drawing paper. Let the sunlight shine through the hole onto another piece of paper, and enjoy the image of the eclipse. Even a partial eclipse must not be viewed directly with the naked eye. The sun's infrared rays will cause retinal damage, and there is even the danger of losing one's sight. The last time a total eclipse was visible in Japan--46 years ago--it is said that many people watched through glass panels darkened with black soot. However, this too is dangerous. The same holds for sunglasses and black shitajiki (sheets of material placed under paper when writing). Although such items will reduce glare, they will not block the infrared and ultraviolet rays harmful to the eye. To view an eclipse directly, observers must use a filter designed for this purpose. Such filters can be purchased at large home appliance stores and elsewhere, but observers should still be careful as there is also a danger of heat stroke if you watch the eclipse for an extended period. Times when the eclipse can be seen in different regions can be found on the Web site of the National Astronomical Observatory of Japan
