On August 12, millions of people will witness a rare total solar eclipse, as the Moon passes directly between the Earth and the Sun, completely blocking sunlight along a narrow path across the planet. It will be the first total solar eclipse visible from mainland Spain in more than a century, while the last total eclipse observable from continental Europe occurred in 2006. A total solar eclipse takes place when the Moon aligns precisely between the Sun and the Earth, casting its shadow onto the planet’s surface. Widely regarded as one of nature’s most awe-inspiring spectacles, a total solar eclipse combines the rare geometric alignment of three celestial bodies with an experience shared simultaneously by thousands, or even millions, of observers. The eclipse marks a historic moment for Spain, where it will be the first total solar eclipse visible from the mainland since 1905.