The last chance in this century to see the transit of Venus across the sun will commence on the morning of June 6 in Guangzhou, along with most of China, even though the 21st Century has barely begun.
The phenomenon occurs when Venus moves right between the sun and the earth. It will last for almost seven hours from 6:12am to 12:49pm. Venus will be observed as a moving black spot across the sun, or as “a birthmark on the sun's face” as described by Alpharabius, the Persian scientist who first discovered the phenomenon in the year 910.
People all over China will be able to witness the transit, while East China is the best place to view the entire process. The next chance to see the spectacle will be on Dec 11, 2117, in 105 years.
People will be able to witness the spectacle with their naked eye. However, like observing a solar eclipse, it is best viewed with a professional filter, or a few pieces of dark film used in X-ray or photos, to protect the eyes from permanent damage – ordinary sunglasses cannot protect your eyes.