Feb 24, 2017

Southern Hemisphere Solar Eclipse

Something strange is about to happen to sunbeams in the southern hemisphere.

On Sunday, February 26th, the moon will pass in front of the sun, transforming rays of sunlight across parts of South America, southern Africa and Antarctica into fat crescents and thin rings of light.


It's a solar eclipse, in which the moon will cover as much as 99% of the sun. Millions of people will be able to witness the event since the eclipse zone encompasses more than two dozen countries in three continents.

There are three types of solar eclipses.

  1. A total eclipse: The moon completely covers the blinding disk of the sun.  The sun’s ghostly outer atmosphere, called the corona, springs into view, mesmerizing onlookers in the path of totality.
  2. A partial eclipse: The moon crosses in front of the sun off-center, leaving a crescent-shaped portion of the sun visible.
  3. An annular eclipse. The moon crosses in front of the sun dead-center, but the lunar disk does not completely block the sun. The edge of the sun juts out on all sides of the moon, creating a bright “ring of fire.”

There are also instances when an eclipse is a hybrid between the first and third types, a total/annular eclipse. This occurs when the curve of the Earth results in the eclipse path moving between the eclipse’s total and annular shadows. A total eclipse can change to an annular eclipse, or vice versa, along sections of the eclipse path!

This eclipse will be an annular eclipse, with a narrow path of annularity snaking across five countries: Chile and Argentina in South America and Angola, the Democratic Republic of the Congo, and Zambia in Africa.  People in those countries can see the “ring of fire” for almost a minute and a half.

Outside that path, the eclipse will be partial.  This means the sun will turn into a crescent—a slender one near the path of annularity and a fatter one away from it.

Caution: The ring of sunlight throughout the eclipse is blindingly bright. Even though most of the sun's disk will be covered, do NOT attempt to observe the eclipse directly with the naked eye. Observers still need to use a solar filter or some type of projection technique. A widely available filter is number 14 welder’s glass or darker. Another option is to look at the sun-dappled ground beneath leafy trees.  The sight of a thousand crescent-shaped sunbeams swaying back and forth on a grassy lawn or sidewalk is unforgettable.

Astronomers are excited about this eclipse mainly because it brings us closer to another one we’ve been anticipating for years:  The Total Solar Eclipse of August 21, 2017.  On that date, the moon will completely cover the sun for a total eclipse visible in the United States from coast to coast, in easy driving distance of a hundred million people. If the weather accommodates, it should be the best observed eclipse in the history of astronomy.

Let the countdown begin!

For more news about eclipses and other celestial phenomena, stay tuned to