The scintillating cosmic phenomenon of a total solar eclipse will be visible to millions of people across parts of Greenland, Iceland, northern Russia, Spain and Portugal on August 12.

It’s the first of three eclipses anticipated over Spain in the next two years. The best way to prepare for safe viewing of the stellar lineup is to locate a pair of eclipse glasses. Sunglasses won’t be enough to protect your eyes for direct viewing of the spectacle.

A total solar eclipse occurs when the moon passes between Earth and the sun, completely blocking the sun’s face. Since the total solar eclipse will occur over Spain in the evening, sky-gazers are in for a rare treat: a sunset eclipse in which they will see a crescent sun setting after the total solar eclipse.

Those in the path of totality, or locations where the moon’s shadow will completely cover the sun, will see a total solar eclipse. People outside the path of totality will be able to see a partial solar eclipse, where the moon only blocks part of the sun’s face. A partial eclipse will pass across the northern United States, Canada, much of Europe and northwestern Africa. Check Time and Date to see when it will occur in your area.

If your location only affords a view of the partial solar eclipse, some of the sun’s powerful light will be visible throughout the event. And any glimpse of the sun’s brightness with the naked eye is not only uncomfortable but also dangerous.