The mid-weeks of August are usually taken over by the Perseids meteor shower, but there’s another contender this year. A partial solar eclipse will be visible on August 11, just hours before the peak of the Perseids.
The moon will cover about 65 percent of the solar disk at the most, with its maximum happening in the East Siberian Sea near the Wrangel Island at 9:47 am UTC (5:47 ET). The eclipse will be visible from many countries in the Northern Hemisphere, with Eastern Canada experiencing it after dawn and North and South Korea able to see the event at sunset. Seoul will see a 35 percent coverage of the Sun.
Scandinavian capitals Helsinki, Oslo, and Stockholm will respectively experience 8, 5, and 4 percent coverage of the solar disk. Scotland will experience similar levels of coverage as well. For Europe and Western Russia, the higher the latitude, the higher the coverage, but in Asia being toward the East also helps. The eclipse will be visible throughout Siberia, Mongolia, and most of China, while the percent cover in Shanghai will be about 20 percent, roughly what people in Iceland are going to experience. Check out a location map here.
This eclipse is part of the Metonic series of eclipses, which repeat almost every 19 years exactly, in a cycle of five. This one is the last in this cycle, with the previous four taking place on August 12, 1942, August 11, 1961, August 10, 1980, and August 11, 1999. The last one was a total eclipse visible across most of continental Europe and attracted similar media interest to 2017’s Great American Eclipse.
The Metonic cycle is important in both ancient and modern calendars – the Babylonians and Ancient Chinese used it, and it is still used in the modern Hebrew calendar. It was also used to calculate the date of Easter in the Middle Ages. The most famous example of the use of this system is probably the Antikythera mechanism, an ancient Greek clockwork computer that, thanks to 37 gears, was able to follow the movement of the Moon and the Sun with respect to the zodiac as well as predict eclipses.
The next solar eclipse will be another partial one on January 6, 2019, visible in Eastern Asia. The next total one will happen on July 2, 2019, across the Pacific Ocean and South America.