Ha Noi (Viet Nam News/ANN) - An annular solar eclipse will occur on May 21 and can be observed in some parts across Vi?t Nam, according to Dang Vu Tuan Son, chairman of the Vi?t Nam Amateur Club of Astronomy.
"Citizen in the capital will be able to see the eclipse between 5.20 - 6.13 in the morning. However, people in other parts of the country can only witness the event after 5.20", Son said.
He added that it could be quite difficult to observe due to its fleeting occurrence and smog.
Son also warned that an annular eclipse was also dangerous to look at directly with the naked eye. Stargazers must use the pin-hole projection method or solar filters as safety precautions instead of cameras, binoculars and telescopes.
The Moon's orbit around Earth and its orbit around the sun are both elliptical in shape. Therefore, their distance varies. When the Moon is on the near side of its orbit, it appears larger than the Sun. If an eclipse occurs at that time, it will be a total eclipse. However, if an eclipse occurs while the Moon is on the far side of its orbit, it appears smaller than the Sun and cannot completely cover it, causing the Sun to look like a ring (annulus), blocking most of its light.