Sunday, 21 June, will see an annular solar eclipse, starting in central Africa, going over Eastern Africa, and then on to the Middle East, Southern Asia and East Asia.

 

The astronomical phenomenon will be very visible in countries like the Democratic Republic of Congo, Central African Republic, South Sudan, Ethiopia and Eritrea.

 

Unfortunately, South Africans will witness only a partial eclipse.  Residents in the north eastern parts of the country will witness a very limited eclipse at sunrise, for example, only 7% of the sun will be covered in Limpopo and only 3,12% in Pretoria. 

 

In other places, like Cape Town, there will be nothing to see, but you can watch the phenomenon livestreamed on various websites.

 

A solar eclipse can be seen when the moon comes between the sun and the Earth, and the moon's shadow sweeps across some parts of the Earth over a few hours. When the moon comes exactly in between, then locations under the central shadow will experience a total solar eclipse, where for a few minutes during mid-eclipse, the moon will completely cover the disc of the sun.

 

However, on 21 June, the moon will cover only about 96-97% of the sun's surface at the maximum point of the eclipse. A ring of exposed sun will be visible at mid-eclipse, which is why it is called an annular (ring-shaped) eclipse.

 

Eclipses are about celestial shadows. The moon goes around the Earth in little less than a month, and the moon and the Earth together go around the sun once a year.  The sun continuously illuminates half of the Earth and the moon, and also continuously casts a shadow behind each of them.  As they move around each other, the moon sometimes comes between the sun and the Earth.  The moon's shadow then falls on a part of the Earth and regions in this shadow will see the sun slowly being covered by the moon over the course of a few hours.

 

Similarly, when the shadow of the Earth falls on the moon, we get a lunar eclipse. Since a solar eclipse happens when the moon comes in between us and the sun, this can occur only during a new moon. Similarly, a lunar eclipse can happen only during a full moon.

 

Though it may look as if the sun and the moon are close together, they are far apart. 

 

If you observe a solar eclipse using a safe method (you can permanently damage your eyesight by looking directly at the sun), you will see the moon beginning to move in front of the sun, gradually covering some of it.  Many ancient cultures interpreted eclipses as events caused by some mythical creature eating the sun (or the moon) at this time. Slowly, the moon will begin to move past the disc of the sun, and continue on its way.

 

As a result of the COVID-19 pandemic, the public will not be able to gather to view the eclipse.  However, the African Astronomical Society has produced posters and a handbook, and a free Android app to inform the public about simple but safe ways to view the eclipse from their homes.