According to Sapo news, between 9:36 and 11:29 tomorrow, the sun will be covered by the moon, precisely 19 years after the last partial solar eclipse visible in Portugal.

The sun will thus appear similar to a crescent moon for almost two hours. The eclipse will be visible throughout the country, but the Azores are where observers will have the best visibility in Portugal. In Ponta Delgada, more than half of the sun's surface will be covered by the moon, with a coverage rate of around 58%. In Lisbon, this figure will be around 40% and will reach its peak at around 10:30 am on Saturday.

The best place to view the eclipse will be from a high point, such as a mountain or a balcony, but be careful. Those who wish to observe the eclipse directly are advised to wear special glasses to protect their eyes from the risks of visible, infrared and ultraviolet radiation. Glasses are sold in pharmacies or other authorised locations. The Lisbon Astronomical Observatory warns that "Incorrect use of solar filters or observation devices, as well as direct observation, can cause instantaneous or gradual blindness without regression” and normal sunglasses should not be used.

The last partial solar eclipse of this kind occurred on 29 March, 2006, exactly 19 years ago. It is no coincidence, since it is a Metonic cycle, an astronomical occurrence that means that every 6,939.69 days, the Moon coincides again in the same position, in relation to the Earth and the Sun, on the same day of the year, in the same region, explains astronomer Alejandro Sánchez to El País.

This will be the first in a series of astronomical phenomena that will reach Portugal until August 2026, when there will be a near-total eclipse of the sun. Later this year, there will be a new lunar eclipse on September 7th and this time, it will be total and visible throughout the country.