Astronomer: ordinary sunglasses won't work for August 12 solar eclipse

A partial solar eclipse will be visible in Estonia on Wednesday, August 12. Astronomer Ullar Kivila, who traveled to Spain to watch the eclipse, said on the R2 Päev radio programme that the eclipse will be total in Spain but only partial in Estonia.

According to him, the last similar eclipse in Estonia occurred in 2015, and the next one covering the same percentage of the Sun will not happen for another 10 years.

Eclipse just before sunset

Kivila noted that the eclipse will be visually interesting in Estonia because it will occur in the evening, right before sunset, meaning viewers won't need to tilt their heads far back — the Sun will sit low over the horizon. At the same time, this could make observation trickier, since a spot has to be found where trees or buildings don't block the view.

He explained that in Estonia the eclipse will make the Sun appear as if its lower part has been cut off, with the Sun resembling a crescent lying on its side above the horizon during the eclipse's peak. The eclipse will begin around 8 p.m., with the Sun most obscured at 20:55. The end of the eclipse won't be visible, as the Sun will set just five minutes after the maximum phase.

Special protective gear required

Since the eclipse won't be total in Estonia, Kivila stressed that observers should use special eclipse glasses, sooted glass, or a welding mask. He warned against looking at the Sun for extended periods even during a partial eclipse, adding that ordinary sunglasses won't help, since they are designed to darken an image rather than allow safe direct viewing of the Sun.

He offered a simple rule of thumb: if you still have to squint and find it uncomfortable to look at the Sun, the equipment you're using isn't suitable enough.