Skywatchers are set to witness a rare total solar eclipse on August 12, when the Moon completely blocks the Sun, plunging parts of northern Spain into darkness in the first total solar eclipse visible from mainland Europe since 2006.
A total solar eclipse occurs when the Moon passes directly between the Earth and the Sun, casting its shadow over a narrow section of the planet. During the brief period of totality, daylight fades into twilight, temperatures may drop, shadows become distorted and some animals exhibit nighttime behaviour.
According to NASA, the phenomenon is possible because the Sun, despite being about 400 times larger than the Moon, is also approximately 400 times farther away from Earth. This unique alignment allows the Moon to appear almost the same size as the Sun, completely obscuring it and revealing the Sun’s outer atmosphere, known as the corona.
The eclipse’s path of totality will begin over a remote region of northern Russia before crossing Greenland, Iceland, Spain and the northeastern tip of Portugal. In Spain, the shadow is expected to travel from around Oviedo in the north to the island of Mallorca.
Observers in northern Spain will experience just under two minutes of total darkness shortly before sunset. In Burgos, totality is forecast to last about one minute and 48 seconds, while slightly longer durations of less than two and a half minutes are expected in parts of Russia and Greenland. Before and after totality, a partial solar eclipse will be visible for approximately one hour and 45 minutes. Partial phases of the eclipse will also be observable across much of Europe, Canada, the northern United States and northwest Africa.
Although solar eclipses occur somewhere on Earth every year, total eclipses are far less common at any single location because the Moon’s shadow follows a narrow path, meaning some regions may wait centuries before witnessing another one.
Spain is expected to experience two more significant eclipse events in the coming years. On August 2, 2027, another total solar eclipse will cross southern Spain, northern Africa and the Arabian Peninsula. The event has been described by astronomers 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.
The country will also 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.
Experts have advised the public never to look directly at the Sun during any stage of a solar eclipse without certified eye protection, warning that doing so can cause permanent eye damage. They recommend using eclipse glasses that meet the ISO 12312-2:2015 international safety standard to safely observe the event.
Health specialists also note that eye damage from viewing an eclipse without proper protection may not be immediately apparent because the eyes lack pain receptors. Studies conducted after the 2024 total solar eclipse in the United States recorded a sharp increase in online searches related to eye pain following the event.