A rare total solar eclipse will plunge parts of northern Spain into darkness on August 12, as the Moon completely covers the Sun in the first total solar eclipse visible from mainland Europe since 2006.
What causes a solar eclipse?
A solar eclipse occurs when the Moon passes directly between the Sun and the Earth, casting a narrow shadow across the planet. During totality, daylight briefly turns into twilight, temperatures can fall, shadows appear unusual, and some animals behave as though night has arrived.
According to NASA, the phenomenon is possible because of a unique cosmic alignment. Although the Sun is about 400 times larger than the Moon, it is also roughly 400 times farther away, making both appear nearly the same size from Earth. This allows the Moon to completely block the Sun, revealing its outer atmosphere, known as the corona.
Path of totality and visibility
The eclipse will first be visible over a remote region of northern Russia before the path of totality moves across Greenland, Iceland, Spain and the northeastern tip of Portugal. In Spain, the eclipse will travel roughly from the northern city of Oviedo to the island of Mallorca.
Observers in Spain will experience less than two minutes of total darkness shortly before sunset. In Burgos, for example, totality is expected to last one minute and 48 seconds. The eclipse will last slightly longer in parts of Russia and Greenland, although totality will still remain under two-and-a-half minutes.
Partial eclipse and future events
Before and after totality, a partial eclipse will be visible for around one hour and 45 minutes. Partial phases of the eclipse will also be seen across much of Europe, Canada, the northern United States and northwest Africa.
While one or two solar eclipses occur somewhere on Earth each year, total eclipses are much rarer for any specific location because the Moon's shadow covers only a narrow path. As a result, some places may wait hundreds of years before experiencing another total eclipse.
Skywatchers in Spain will not have to wait long for another major event. On August 2, 2027, another total solar eclipse will cross southern Spain, northern Africa and the Arabian Peninsula. The event has been described by some as the "eclipse of the century" because totality is expected to last six minutes and 23 seconds, making it the longest total solar eclipse of the 21st century.
Spain is also expected to witness an annular, or "ring of fire," solar eclipse on January 26, 2028, when the Moon will cover the centre of the Sun while leaving a bright ring of sunlight visible around its edges.
Safety warnings from experts
Experts have warned that people should never look directly at the Sun during any phase of a solar eclipse without proper eye protection, as doing so can cause permanent eye damage. They recommend using eclipse glasses that meet the ISO 12312-2:2015 international safety standard, which filters harmful ultraviolet rays.
Health experts also note that because the eyes lack pain receptors, damage may not be immediately noticeable. Research conducted after the 2024 total solar eclipse in the United States found a sharp increase in online searches for "my eyes hurt" following the event.
