Safety is key as you gear up to watch the annular solar eclipse on June 21
Pic/AccuAstronomy's Twitter
On June 21, 2020, an annular solar eclipse will take place. The annular eclipse of the sun, is a special case of the total solar eclipse in which the Moon does not cover the Sun completely. On a narrow track over the Earth, people can see the moon traversing on the Sun and in a short period of time one can see a 'ring of fire' in the sky. Over a large landmass, north and south of this track, people will be able to observe a partial solar eclipse.
ADVERTISEMENT
Apna time aayega
Bhuj will be the first town to see the beginning of the eclipse at 9:58 am. The eclipse ends four hours later at Dibrugarh at 2:29 pm.
The annular phase of the eclipse will be first seen over Ghersana at the western boundary of India at 11:50 am. It will last for 30 seconds. Kurukshetra, about 155 km, almost due north of Delhi will be the best place. Dehra Dun is another place where the annular eclipse can be seen. Kalanka peak in Uttarakhand will be the last major landmark to see the eclipse at 12:10 pm lasting for 28 seconds.
The importance
How significant this is, is evident when you consider that this will be the last eclipse to be seen from India for the next 28 months. We will see the next eclipse on October 25, 2022. It will be a solar eclipse, a partial solar eclipse and visible only from the west of India. Next Umbral lunar eclipse that will be visible from India will take place on September 7, 2025.
Stay safe
There are certain 'how to' and 'how not to' to observe the eclipse. It is important to note that the Sun is a very bright object. Looking at it directly can cause permanent damage to the retina.
There are some safe methods to observe the Sun, and a few of those are the use of special goggles made for looking at the Sun. These goggles filter the sunlight for safe viewing. We have something called welder filters which welders use in fabrication shops. These are dark filters to protect their eyes. Such welders' filters can be used to see the Sun.
There is yet another method called pinhole imaging. One has to make a pinhole in a card sheet and hold it under the Sun. At some distance keep a screen of white paper. The image of the Sun can be seen on this sheet. The size of the image can be increased by increasing the distance between the card sheet with pinhole and the screen.
Go the natural way by looking from under a tree. Small gaps between the leaves also act like pinholes. You can also use a small piece of a mirror (such as in a makeup compact) and place a card sheet with a small hole on it. One can then reflect the Sun's image on a distant wall.
The Sun can be imaged on a sheet of white paper using a pair of binoculars or a telescope.
That's unsafe
Having cited safe methods to observe the Sun, there are some unsafe ones too, to be avoided completely.
Looking at the Sun directly is very dangerous to the retina of the eye. It can lead to permanent damage to the retina.
Do not use ordinary dark glasses as these are meant to cut only the terrestrial light.
Reflection in water has been advocated by some to look at the Sun, but a water reflection does not reduce the intensity of sunrays to safe limits. The water surface cannot be kept constant, so reflected sunrays are also moving constantly and cause eyestrain.
Looking at the Sun through a glass which is coated with lampblack or carbon soot, is unsafe.
Happy viewing, but keep safety both for eyes and COVID-19 guidelines in mind.
The columnist is director, Nehru Planetarium, Mumbai
Send your feedback to mailbag@mid-day.com
Catch up on all the latest Mumbai news, crime news, current affairs, and a complete guide from food to things to do and events across Mumbai. Also download the new mid-day Android and iOS apps to get latest updates.
Mid-Day is now on Telegram. Click here to join our channel (@middayinfomedialtd) and stay updated with the latest news
Subscribe today by clicking the link and stay updated with the latest news!" Click here!
