Will you also watch the solar eclipse tomorrow? Our science expert tells you how best to do that | Science & Planet

“An eclipse occurs when the moon and sun are aligned. The eclipse is possible because the distance between the earth and the sun is about 400 times greater than the distance between the earth and the moon and the diameter of the sun is about 400 times that of the moon. Because the difference is almost the same, the celestial bodies appear almost the same size and you can see an eclipse,” says science expert Martijn Peters.

“You don’t have the same amount of eclipse everywhere,” says Peters. “In the area of ​​the ‘core shadow’ the eclipse is maximum. That is about 100 kilometers in diameter. Around it lies the ‘penumbra’, in which the sun is only partly covered. The farther you are from the core shadow, the less eclipse there will be.” In Belgium it will be a partial solar eclipse.

“Every year there are about two to five eclipses somewhere in the world. However, you must be extremely lucky that the core shadow just travels over your land and is visible. A total solar eclipse is therefore not only one of the most spectacular, but also the rarest natural phenomena,” says Peters.

“But it can also be worth the effort in the penumbra. Just last year, in June, we could see how the moon covered about 27 percent of the sun’s diameter. But the most memorable for many will have been the August 11, 1999 solar eclipse. At that time, no less than 94 percent of the sun’s diameter was obscured,” says Peters, “In 2026 we will experience this again. On August 12 that year, around 8 p.m., 90 percent of the sun’s diameter will disappear. If you want to see this total eclipse in full, you have to go to Spain.”

“In Belgium, the partial eclipse is clearly visible,” says Peters. “At 11:09 a.m., the moon will begin to cover the sun from the right side. The solar eclipse reaches its peak around 12 noon. At that time, the moon is at the top of the sun, covering about 30 percent of its diameter. At 13 o’clock the moon disappears again along the left side of the sun.”

So plenty of time to enjoy the eclipse, at least if the weather is good. At the moment it is predicted that the day will start with a lot of low clouds. Gradually more and more clearings appear. It will remain dry in most places.

“A solar eclipse is a beautiful natural phenomenon to watch, but you should be careful,” warns the science expert. “When you look directly at the sun, ultraviolet light floods the retina and causes damage. This can cause light sensitivity and pain from burning the cornea. Usually, these ‘solar ratitis’ symptoms disappear within 24 hours. But serious damage can also occur when the UV light burns a hole in the retina (solar retinopathy). This can create a small blind spot. By the way, the retina has no pain receptors, so you don’t feel the damage. You only notice it later when it is already too late.”

Wearing protection is therefore the message. “Eclipse glasses are easy and safe,” says Peters. “These glasses are typically 100,000 times darker than sunglasses and are made of black polymer. That is a flexible resin infused with carbon particles. This blocks all UV rays and almost all visible light. So never use regular sunglasses.”

“If you don’t have eclipse glasses, no problem,” says Peters. “You can make a camera obscura. Sounds expensive, but is dirt cheap. Make a hole in a piece of cardboard and let the sun shine through it. This way you can project the eclipse onto a surface with the sun safely behind your back.”