Warning: eclipse peaks 20:13 tonight — never look without glasses
Austria gets a deep partial solar eclipse this evening, the strongest since 11 August 1999. In Vienna about 89 percent of the sun will be covered.
The timing is unusual and it is the reason this one is worth stepping outside for. In Vienna the eclipse begins at 19:22, the maximum comes at 20:13, and the sun sets one minute later at 20:14. Because the deepest point coincides almost exactly with sunset, the Austrian Astronomical Association notes that the usual side effects — the strange pale light, the noticeable drop in temperature — may be less obvious than during a midday eclipse. What you may get instead, if the sky is clear, is an unusually dark and dramatic sunset. Coverage is deepest in the west: around 90 percent in Bregenz, about 84 percent in Graz, with the maximum in Lienz at 20:18. Start and end times shift slightly depending where you are.
Never look at the sun without proper protection. Even during a partial eclipse the radiation can damage your eyes severely and permanently, and the damage is not something you feel happening. You need tested eclipse glasses; ordinary sunglasses are not enough, and neither is a very dark pair. Do not look through binoculars, a telescope or a camera lens while wearing eclipse glasses — the optics concentrate the light and can destroy the filter almost instantly. Those instruments need their own solar filter fitted in front of the lens.
Glasses have been hard to find. Queues formed outside Vienna shops and many outlets have sold out, so if you have not got a pair, use an indirect method instead. Punch a small hole in card and project the sun onto paper, or turn your back to the sun and let the light fall through a colander. Do not look through the holes — only the projected image is safe.
Because the sun sits very low by the maximum, find somewhere with a genuinely clear view west and west-north-west; a single row of trees or a building will hide it. Austria is outside the zone of total eclipse, which runs over Greenland, Iceland, northern Spain and the Balearics. Stay out afterwards for the Perseid meteor shower, which peaks tonight.