Coming up this October is the annular total solar eclipse that will captivate viewers in northwestern United States, Brazil and parts of Central and South America. This phenomenon is caused by the Moon's "ring of fire" appearance during its farthest point from Earth.
When Will the Ring of Fire Appear?
A mesmerizing annular total solar eclipse will grace the skies on October 14, offering a celestial spectacle visible to millions worldwide. This celestial event will start in the northwestern United States, traverse through Mexico and Central America, and conclude its breathtaking journey in Brazil.
This celestial spectacle will be observable, commencing in Oregon and traversing regions of California, Nevada, Utah, New Mexico, Texas, and a small section of Colorado and Arizona. The eclipse will follow a path spanning 130 miles in width, with visibility initiating near Eugene, Oregon, at 9:16 A.M. PDT on October 14 and concluding near San Antonio, Texas, at 11:56 A.M. CDT.
But for those who find themselves beyond the eclipse's direct path, the possibility of witnessing a partial solar eclipse still exists, contingent upon favorable weather conditions.
An annular solar eclipse is a celestial occurrence wherein the Moon positions itself between the Earth and the Sun, albeit not entirely covering the Sun due to its elliptical orbit.
This differs from a total solar eclipse, where the Moon completely obscures the Sun, plunging the surroundings into a brief period of daytime darkness. The term "annular" derives its meaning from the Latin word "annulus," signifying a ring-like shape.
During an annular solar eclipse, the Sun's outer edge remains visible, creating a luminous ring that encompasses the darkened disk of the Moon. This captivating phenomenon transpires because the apparent size of the Moon in the sky is smaller than that of the Sun, meaning it does not appear large enough to completely block the Sun's radiant presence.
Moon's Distance A Factor in the Formation of the Ring of Fire
The Sun and the Moon seem nearly the same size in the sky due to their different distances and sizes; this is because the Sun is about 400 times larger and 400 times farther from Earth than the Moon, resulting in both appearing roughly half a degree wide.
However, the Moon follows an elliptical orbit, varying its distance from Earth, ranging from about 355,000 kilometers at perigee to approximately 397,000 kilometers at apogee.
This fluctuation of about 10% in distance leads to a 10 percent change in the moon's apparent size in the sky during half of its orbital journey, a critical factor in the occurrence of an annular eclipse.
Five days prior to an upcoming eclipse, the Moon will reach its farthest point from Earth, known as apogee, situated at around 391,000 kilometers away, although the precise measurement varies based on factors like observer location and time of day.
At this distance, the Moon will have an apparent width of 0.51 degrees, while the Sun, positioned at an average distance of 149 million kilometers from Earth, will have an apparent width of about 0.54 degrees.
Due to a slight difference in apparent size caused by the Moon's position at apogee, an annular eclipse occurs where the moon does not fully block the sun's disk, leaving a luminous ring or annulus encircling the sun.
Despite technically being a partial eclipse, it is a unique and perfectly centered celestial event, obscuring up to 91% of the sun's surface during three main phases: first contact, annularity, and last contact.
RELATED ARTICLE : Annular Solar Eclipse 2023: North America's First 'Ring of Fire' To Be Visible From Eight US States; Here's How To Watch
Check out more news and information on Solar Eclipse in Science Times.
