How to watch a solar eclipse?

How to watch a solar eclipse

WATCH A SOLAR ECLIPSE. Can you see a solar eclipse with the naked eye or do you need to buy goggles? What you need to know to observe a solar eclipse safely.

[Mis à jour le 25 octobre 2022 à 14h39] A solar eclipse, this astronomical phenomenon that occurs when the Moon passes in front of the Sun, lasts about 2 hours, and cannot be observed with the naked eye under pain of serious damage to the retina, and even if it is not always visible depending on the weather. A number of precautions must be taken to enjoy the celestial spectacle without risk.

It is always necessary to be equipped with protections designed for a solar eclipse. If you do not have special glasses sold in pharmacies, opticians or astronomy shops, there are alternatives to observe a solar eclipse indirectly, using an eclipse box or a sheet of paper. hole for example. Find all our advice in our file.

Can you watch a solar eclipse without glasses?

If you do not have suitable glasses for observing a solar eclipse, do not take any risks and do not try to admire the spectacle with the naked eye. The UV rays emitted by the sun are very dangerous for the eyes and can cause irreversible damage to different parts of the eye. In particular, you risk burning part of your retina or even damaging your cornea. To enjoy a solar eclipse safely, you must obtain protective equipment that will allow you to watch the sun without danger or to observe the eclipse indirectly.

There are a few tricks you can use to enjoy the event safely and without glasses. For example, you can make an eclipse box that will allow you to watch the show without looking directly at the sun. If you haven’t had time to create your eclipse box, you can always pierce a slightly thick sheet using a needle. Orient the sheet so that sunlight passes through the hole and look at the light spot that occurs on the ground: you will see the eclipse projected on the ground.

How to watch a solar eclipse?
If you don’t have time to buy special eclipse glasses, there is always a plan B. © Andrei Samsonov/TASS/Sipa USA/SI (published 25/10/2022)

What glasses should I buy to watch a solar eclipse?

Protective glasses designed for eclipses are the most suitable equipment to observe the phenomenon in complete safety. They are available for sale in different places:

Some pharmacies offer glasses suitable for observing eclipses. To get them, you will have to pay between 2 and 5 euros per pair.

You can also go to an optician to buy eclipse goggles. A number of optical stores offer this equipment for a few euros. The stores Krys or Optics 2000 sell this type of glasses on the occasion of solar eclipses.

Specialty astronomy stores usually sell eclipse viewing glasses. This is also the case for certain brands that have an astronomy department. This is particularly the case of Observation World located in Paris in the 4e district or shops Nature and Discoveries established throughout France.

If you prefer to buy on the internet, many online sales sites allow you to buy this type of glasses. This is the case ofAmazonof Rakuten or sites specializing in astronomy such as the astronomy house.

How to watch a solar eclipse?
Special eclipse goggles © Lost_in_the_Midwest – stock.adob

Can you watch a solar eclipse with sunglasses?

You should never use conventional sunglasses to observe a solar eclipse. Even the darkest lenses do not protect your eyes from the sun’s rays. As the magazine explains Science and Future, during an eclipse, the infrared rays emitted by the sun are extremely dangerous for your eyes. These can cause irreversible retinal burns that are painless at the time. This is why it is essential to wear glasses specifically designed for eclipses.

If you don’t have glasses or equipment to observe the sun directly, you can make an eclipse box to take advantage of the event and admire the eclipse indirectly.

To do this, take a cardboard box and attach a white sheet to the inside. On the opposite side, create a first opening that will let the light through. Then attach aluminum foil to this opening and pierce it with a hole using a needle. At least ten centimeters from this opening on the same side, make a second one that will allow you to look into the box. Then seal the box with adhesive tape. The eclipse box works on the pinhole principle which allows you to admire the phenomenon by projection.

At the time of the eclipse, stand with your back to the sun, so that its rays enter through the small hole in the aluminum foil. Looking through the small opening next to it, you will see the eclipse projected into the bottom of the box onto the white sheet of paper.

Which solar filter to use to watch a solar eclipse?

There are solar filters that allow direct observation of the sun using a telescope or astronomical telescope. This filter is used to protect the eyes of the observer by allowing only a tiny amount of light to pass into the device.

If you use a pair of astronomical binoculars, you will need to equip them with a suitable solar filter to take advantage of the eclipse. Depending on the outer diameter of your binoculars, you can find this type of equipment in astronomy shops or on dedicated websites such as the astronomy house.

There are filters specifically designed for different models of telescopes and refractors. In order for the filter to perfectly cover the opening of the telescope or telescope, the diameter of the instrument must be checked. The Stelvision store offers three sizes of sun filters: ASTF80, ASTF140 and ASTF200, for telescopes or telescopes with an aperture between 100 and 290 millimeters. It’s up to you to choose the model compatible with your instrument.

How to watch a solar eclipse?
Solar filter attached to a telescope © astrosystem – stock.adobe.com

The welder’s mask: another alternative for watching a solar eclipse

Special protective glasses are the best equipment to admire an eclipse. However, it is not always possible to obtain them in time to take advantage of the event. Welding masks can be an interesting alternative to watch the eclipse without danger. However, it is necessary to make sure of the type of mask used. In fact, only grade 14 arc welding masks will protect your eyes from the sun’s rays. The grade of the mask is usually indicated on it. If in doubt, don’t take the risk and don’t use it!

Is it dangerous to watch a solar eclipse?

It is extremely dangerous to look at the sun directly with the naked eye. The latter emits light rays that can cause irreversible damage to the eye. In the least serious cases, these lesions are limited to conjunctivitis or inflammation of the cornea, which, caught in time, can be cured. But the main risk is to suffer a burn of the retina which is irreversible or even a lesion of the lens which can lead to an early cataract. These wounds are painless, especially when the sun is less dazzling because it is partially obscured. This is why one must be very vigilant when observing an eclipse and not give in to the temptation to admire it with the naked eye.

“A solar eclipse observed in Tokyo”

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