The Full Thunder Moon arrives July 27 at 4:21 p.m. EDT (2021 GMT), right in the middle of the longest "blood moon" eclipse of the century. Observers in the Eastern Hemisphere — Eastern Europe, Africa and Southeast Asia — will see the moon block the sun for up to 1 hour and 43 minutes.
Viewers in the eastern U.S. won't be able to see the moon at its fullest phase, because it will be below the horizon. However, the just-past-full moon will still look full to the casual observer when it rises around 8 p.m. local time. The sun will set about 15 minutes after moonrise, and four of five naked-eye planets will become visible — provided the horizon is flat and the sky is clear.
The July full moon will rise just 2 minutes after the sun sets in New York, according to timeanddate.com. New Yorkers will miss the eclipse, which starts at 1714 Universal Time, or about 1:14 p.m. EDT. [How Lunar Eclipses Work (Infographic)]
To catch the entire total lunar eclipse, one has to be watching the moon from at least as far east as Cairo or Ankara, Turkey. In Ankara, the penumbral phase of the eclipse (when the moon passes through the outer part of Earth's shadow) will start at 8:14 p.m. local time (1:14 p.m. EDT; 1714 GMT), and the more visible umbral shadow will hit the moon at 9:24 p.m. local time (2:24 p.m. EDT; 1824 GMT).
The classic "blood moon," or total lunar eclipse, will start at 10:30 p.m. (3:30 p.m. EDT; 1930 GMT) and will end at 12:13 a.m. on July 28 (5:13 p.m. EDT or 2113 GMT on July 27). The umbral phase will end when the moon emerges from the dark part of the Earth's shadow at 1:19 a.m., and the penumbral phase will end at 2:28 a.m.
Going farther east, the eclipse starts later at night, so that the moon will be higher in the sky. In New Delhi, the eclipse's partial phase starts at 11:54 p.m. local time; the moon will turn red at about 1 a.m. on July 28. Maximum eclipse is at 1:51 a.m. local time, and the moon emerges from the center of the Earth's shadow at 2:43 a.m. The partial eclipse ends at 3:49 a.m., and the penumbral phase ends at 4:58 a.m. local time.
Most European observers will see that the eclipse is already underway at moonrise, while those on the eastern edge of the area of visibility, in southeast Asia, Japan and Australia, will see the moon setting during the eclipse.
North American skywatchers needn't despair, though. From the Western Hemisphere, the full moon will share the sky with the naked-eye planets, and for a short time, all of them will be above the horizon at the same time — though two of them, Mercury and Mars, will be grazing the horizon when that happens.
On July 29, at 8:32 p.m. EDT, according to heavens-above.com, the moon will be about two days past full. In New York, Mercury is just above the horizon (it sets 3 minutes later) and Mars is just rising (the planet rises at 8:32 EDT). Meanwhile, Venus is still visible in the western sky, with Jupiter in the south and Saturn in the east.
Some Southern Hemisphere observers will get all five naked-eye planets (Mercury, Venus, Mars, Jupiter and Saturn) plus a full moon — and the lunar eclipse. From Cape Town, South Africa, the full moon occurs at 10:20 p.m. local time on July 27. The moon rises at 5:50 p.m. local time that day. The sun sets a few minutes after the moon rises, at 6:03 p.m. local time.
After the sky darkens enough to see the planets — the end of nautical twilight is at 7 p.m. — one can see Mercury in the western sky, 5.9 degrees above the horizon, and Venus about 30 degrees up from the horizon, both in the constellation Leo. Meanwhile, looking toward the east, one will see Mars and the rising moon; Mars will be about 16 degrees high. Looking toward the north and high in the sky, one will see Jupiter, and to the east, Saturn.
Meanwhile, the lunar eclipse starts at 7:14 p.m. in Cape Town, with the moon touching the penumbra. The partial phase of the eclipse starts at 8:24 p.m., and the "blood moon" starts at 9:30 p.m. The moon reaches the deepest part of the Earth's shadow at 10:21 p.m. The total phase ends at 11:13 p.m., and the partial phase ends at 12:19 a.m. on July 28. The moon finally emerges from the penumbra at 1:28 a.m. local time.
The "Thunder Moon"
Native Americans and other indigenous people had several different names for the full moon of July. Like most full moon names, these monikers reflect the fact that in the Northern Hemisphere it is summer and in the Southern Hemisphere it is winter. The name "Thunder Moon," according the Old Farmer's Almanac, was adapted from native peoples in what is now the United States, where summer is thunderstorm season, especially in the Northeast and Midwest. According to the Ontario Native Literacy Coalition, the Ojibwe called this moon the Raspberry Moon, while the Cree called it the Feather Molting Moon, as some birds molt at this time of year.
The Māori of New Zealand called the July-to-August lunar month Here-turi-kōkā, which they described as "The scorching effect of fire is seen on the knees of man," according to the Encyclopedia of New Zealand.
Aside from evocative names for full moons in July, lunar eclipses have had many associations in different cultures. The Maya and Inca saw the lunar eclipse as a manifestation of a jaguar eating the moon, according to a story in National Geographic, "Lunar Eclipse Myths from Around the World." While Western culture tends to see eclipses as bad omens, the Hupa of California interpreted the events as the moon being attacked by his (the Hupa saw the moon as male) pets and then healed by his wives. [Eclipse Superstitions Are a Thing of the Past, and the Present]
In some Islamic traditions, there is a prayer associated with lunar eclipses, called the Salat-al-Kusuf, which should be accompanied by doing good deeds. Eclipses were seen as a way for Allah to strike fear in the hearts of the congregations (interestingly, Muhammad is supposed to have told his people that eclipses are expressly not related to human lives, but rather reflect the will of Allah).
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