On May 20 a solar eclipse will block out most of the sun, leaving a spectacular ring of fire
shining in the sky for observers located along the eclipse’s path. The event is what’s known as an annular solar eclipse, from the Latin “annulus,” meaning “little ring”, and its full glory should be visible from much of Asia, the Pacific region and some of western North America, weather permitting. At its peak, the eclipse will block about 94 percent of the sun’s light. Other parts of the United States and Canada will still see a partial solar eclipse, without being treated to the ring of fire effect, though the East Coast will miss the event since the sun will have set before it begins. The eclipse will occur in the late afternoon or early evening of May 20 throughout North America, and May 21 for observers in Asia. Solar eclipses occur when the moon comes between Earth and the sun, casting a shadow on our planet. When the moon lines up perfectly with the sun and blots out all of its light, the result is a total eclipse. Partial eclipses cover only part of the sun’s face. Annular eclipses are similar to total eclipses in that the moon lines up with the sun dead-on. But in this case, the moon is close to apogee, the farthest point from Earth in its elliptical orbit around our planet, so it’s a smidge too small in the sky to cover the solar disk completely. As a result, a ring of bright sunlight will still blaze around the moon’s circumference. Like other types of solar eclipses, annular eclipses are spectacular but potentially dangerous skywatching events. Care must be taken to observe them properly.