Croatia set for rare pre-dawn lunar eclipse this Friday

Skywatchers across Croatia will have an unusual early-morning spectacle to look forward to this week, with a deep partial lunar eclipse visible on Friday, 28 August.

The eclipse will be particularly striking because at its maximum, 96.3% of the Moon’s disc will be inside Earth’s darkest shadow, making it appear very close to a total lunar eclipse. It will nevertheless officially remain a partial eclipse because a small part of the Moon will remain outside the umbra.

The partial phase will begin at approximately 4.33am Croatian time, with the maximum expected at around 6.12am.

The timing presents both an opportunity and a challenge for observers in Croatia. At the height of the eclipse, the Moon will be extremely low above the western horizon and will soon set.

For observers in Zagreb, Rijeka, Zadar, Split and Karlovac, more than 93% of the eclipse should be visible before the Moon disappears below the horizon, according to astronomical calculations cited by Zagreb Astronomical Observatory.

The best viewing locations will therefore be those with a clear, unobstructed view towards the west and south-west. Buildings, hills and trees could block the Moon during the most impressive part of the event.

As the Moon moves deeper into Earth’s shadow, part of its surface could take on a red, orange or copper colour. This happens because sunlight passing through Earth’s atmosphere is scattered before some of the longer red wavelengths reach the Moon.

Unlike a solar eclipse, no special eye protection is required to watch a lunar eclipse. The event can be viewed safely with the naked eye, while binoculars or a telescope can make the changing colours and edge of the shadow easier to see.

For many parts of Croatia, the event will be a race against sunrise and moonset — but those with a clear western horizon could be rewarded with one of the most striking astronomical sights of the summer.