Within four months, the French will be able to witness “a major astronomical phenomenon”, according to the AFA (French Astronomy Association). On August 12, a total solar eclipse will cross the Northern Hemisphere and will be visible at least partially in a large part of Europe.
In mainland France, “the last visible total eclipse dates from August 11, 1999” and the next one is “planned for September 3, 2081,” notes Eclipse Infothe system developed by the AFA. You should therefore not miss the one on August 12. It promises a striking spectacle: the Moon will be placed between the Earth and the Sun, erasing daylight.
Better to be near the Pyrenees
The eclipse will not be total everywhere. It will completely darken the sky in a band crossing Spain, from Oviedo to Palma via Burgos, but it will be partial in France. On that day, it is better to be “in the west and south of the country”, according to Eclipse info: “up to 99% of the solar surface” will be obscured there, notably in Biarritz (99.5%) compared to 90% in Strasbourg for example. (see infographic below).
To fully enjoy the experience, the weather conditions will need to be right. Namely “clear skies”, “good visibility, without pollution” and “low humidity”, specifies Météo-France.
But will everyone have the chance to observe the eclipse? Not so sure: Alain Cirou, the general director of the French astronomy association (AFA) warned Thursday of a possible “shortage” of UV-protecting glasses. He sounds the alarm and calls for not repeating the mistakes of 1999, where “the last few days had been crazy for finding glasses”.
Beware of “eclipse blindness”
An eclipse, even if it is partial, requires the use of special glasses. When this phenomenon occurs, we no longer have the reflex to turn our eyes away from the Sun. However, “a few seconds of exposure to direct sunlight can permanently burn [la partie centrale de la rétine]even if more than 99% of the solar disk is hidden by the Moon,” explains the astronomers.
“Eclipse blindness” can be temporary or permanent. Since the retina does not have pain receptors, damage can occur without feeling anything. To protect yourself, you must wear glasses that meet the ISO 12312-2:2015 standard. “Only grade 14 welder’s glasses provide equivalent filtration,” adds Eclipse info.
Where to find special glasses?
Astronomy associations, specialized stores and websites, opticians, pharmacies, scientific institutions… It will be possible to buy these glasses in several places. “Their price can vary from 1.5 to 4 euros per pair,” slips Éclipse info. In certain tourist communities, they could be distributed free of charge. But not sure there is something for everyone.
Astronomers therefore warn against false alternatives, such as the basin of water, photo film negatives, CDs/DVDs or metal packaging. In the same way, stacking several pairs of glasses or wearing sunglasses does not guarantee any safety.
If you are unable to find special glasses between now and August 12, you can always opt for indirect observation and the Pinhole technique: all you need to do is “make a small hole in a piece of cardboard to project the image of the Sun onto a flat surface”, then use an object (a strainer, a skimmer, etc.) to “project images of the solar crescent onto the ground”, summarizes Eclipse info.
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