A total solar eclipse will sweep across Greenland, Iceland, Portugal and northern Spain on August 12, the first time totality has been visible in continental Europe since 2006, according to the European Space Agency.
The eclipse occurs when the Moon passes between the Sun and Earth, casting a shadow that completely blocks sunlight along a narrow path, according to NASA. A partial eclipse, in which only part of the sunlight is blocked, will be visible across parts of Europe, Africa and North America.
Where to see it
The path of totality stretches 8,300 kilometres (5,157 miles), beginning over the Arctic coast and passing near the North Pole before crossing Greenland, Iceland, northeastern Portugal and northern Spain, according to EarthSky. Observers in Greenland will have just over two minutes of totality; those in northern Spain can expect about 20 seconds if weather conditions allow.
The eclipse will pass through Galicia and then the Balearic Islands at nightfall, accelerating the shift from day to night, according to the Spanish Scientific and Advisory Committee for the Eclipse Trio. For those outside the path, the ESA will stream the event live from the Astrophysical Observatory of Javalambre in Teruel, Spain.
Why it matters
August 12 marks the first total solar eclipse visible in continental Spain since 1905 and the first of three the country will witness before 2028, the ESA said. The most recent total solar eclipse visible from the United States, Mexico and Canada occurred in April 2024.
Carole Mundell, the ESA’s science director, said a total solar eclipse was one of those rare moments when millions of people could look at the sky together and feel awe and curiosity. She added that it was a shared moment connecting people to the universe and a reminder that the desire to explore is one of humanity’s greatest drives.
Watching safely
Looking directly at the sun is never safe except during totality, when the light is completely blocked. Certified eclipse glasses or a handheld solar viewer are required at all other times. Standard sunglasses are not a substitute; eclipse glasses are thousands of times darker and meet an international standard. Torn, scratched or damaged glasses should not be used.
NASA warns that looking at the sun through optical devices such as camera lenses, telescopes or binoculars while wearing eclipse glasses is also dangerous. Solar rays concentrate as they pass through optical equipment and can burn through filter material, causing serious eye injury.
The science
During the eclipse, scientists plan to launch high-altitude balloons to capture images of the event and reproduce a 1919 experiment that confirmed Albert Einstein’s general theory of relativity by measuring how the sun’s gravity bends light from distant stars, according to the Spanish committee. Citizen scientists are invited to build their own instruments to track atmospheric changes as the sky briefly darkens.
The next total solar eclipse will pass through southern Spain, northern Africa, Saudi Arabia and Yemen on August 2, 2027, NASA said. The next one visible from the United States will cross Alaska on March 30, 2033. Continental US viewers will wait until August 22, 2044, when totality reaches North Dakota and Montana, followed by a coast-to-coast eclipse on August 12, 2045, with a path spanning California, Nevada, Utah, Colorado, Kansas, Oklahoma, Arkansas, Mississippi, Alabama and Florida.
