June 21, 2020 is going to be special as an annular solar eclipse is going to occur that day. The Moon is going to obstruct the light coming from the Sun, allowing only a ‘ring
of fire” to be visible.
Solar eclipse observation should be a fun educational activity and to ensure that it stays that way, SPACE India has some guidelines that you must follow while observing the eclipse for maximum safety.
How the Sun can damage our eyes
You might’ve seen someone burn a piece of paper or a leaf with a magnifying glass (a lens). It happens because the lens focuses on the energy of sunlight at one point.
The human eye also has a lens in it that focuses light on the retina. If too much sunlight goes through this lens, it can end up burning a hole in our retinas.
Since retinas do not have any pain receptors, we wouldn’t even feel anything while our eyes are getting damaged.
Failure to protect our eyes may lead to instant and permanent blindness or significant damage to sight.
Things that you shouldn’t do
First thing that you should keep in mind is never to look at the Sun directly. Neither should you use dark sunglasses, homemade filters, tinted glass,old floppy disks, food wrappers, x-ray films for the same.
Looking at the sun through optical devices such as telescopes, cameras and binoculars without filters specifically designed for them is also extremely dangerous. It is not safe to use telescopes, binoculars, cameras in combination with eclipse glasses.
Eclipse glasses and solar filters should not be used without inspection. They may have holes or scratches on them. To inspect, place them in direct sunlight and look at their shadow, if you see sunlight leaking through or any bright spots, discard them.
If any children are to observe the eclipse, make sure to teach them all the rules and keep a close watch on them as they may try to take off their glasses.
Things you should do
You can either observe the eclipse directly or indirectly.
Direct methods include:
- Observing the eclipse while wearing eclipse glasses. Use them only after inspecting them properly.
- Using Welder’s glass grade 14 or higher to view the eclipse. To use it, place it between your eyes and the Sun.
- Using telescopes, binoculars, and cameras to observe the eclipse after attaching a suitable solar filter.
Note: To aim a telescope at the Sun, point it in the general direction of the Sun (without looking through the eyepiece) and move it around till the size of the telescope’s shadow becomes minimum.
Indirect methods include:
An image of the eclipse can be projected onto a surface using a telescope. Point the telescope in the direction of the Sun such that the size of its shadow is minimum, place the surface in front of the outlet of the telescope (without using a lens and filter)
Make sure that the surface isn’t flammable.
Use a pinhole projector to get an image of the eclipse on another surface. Place the projector in the path of the sunlight, observe the eclipse projected
Find the image of the sun being reflected off of the mirror and move the ball in such a way that it is projected on the wall in front of you. Vary the distance between the ball and the wall until the image becomes focused and clear. Alternatively, you could also use a lens and vary its distance from the projector to focus the image
Now that you have all the necessary knowledge, go out and enjoy this grand spectacle of nature while following all the rules.