The moon will officially become full Aug. 26 at 7:56 a.m. EDT (1156 GMT), but the moon can typically look full to casual stargazers a day before and after its peak. For New York City observers, that's after moonset, but the moon won't be noticeably smaller when it rises again at 8:01 p.m., some 24 minutes after the sun sets.
Before the nearly full moon sets on that morning, Mercury will be near its greatest western elongation (or greatest angular distance) from the sun at about 3:59 p.m. EDT (1959 GMT), according to NASA. The planet will be 18.3 degrees from the sun along the line of the ecliptic, which is a projection of the plane of Earth's orbit against the sky. (Your clenched fist held at arm's length measures about 10 degrees.) [The Brightest Planets in August's Night Sky: How to See Them (and When)]
On Aug. 26, Mercury will be visible very close to the eastern horizon, at about magnitude 0, equal to the brightness of the star Vega. The planet will rise at 4:46 a.m. local time in New York. At that time, the sun will be a bit less than 18 degrees below the horizon; astronomical twilight will begin at 4:38 a.m. So, catching sight of the planet will mean competing with a brightening sky.
Meanwhile, Venus will be an "evening star," still well placed for viewing as the planet sets at 9:10 p.m. on Aug. 26 in New York. Soon after sunset, the -4.6-magnitude planet will be visible against the sky, even though it will not be completely dark yet. (The lower the magnitude, the brighter the object.) The full moon, meanwhile, will be rising in the east.
Mars will rise at 6:20 p.m. on Aug. 26 and will set at 3:05 a.m. the next morning, so it will offer good views all night. Jupiter also will be well placed for evening viewing, though the planet sets at 10:38 p.m. for skywatchers in New York; Saturn will set at 1:25 a.m. on Aug. 27 in New York. (You can find out exactly when and where the planets will be visible from your specific location via timeanddate.com/astronomy.)
Even from a dark-sky location, the full moon tends to overwhelm the fainter stars. That said, asterisms such as the Summer Triangle — which consists of the stars Vega, Deneb and Altair — will be prominent and easily spotted. About an hour and a half after sunset in the Northern Hemisphere, you can look nearly straight up to find Vega, which, at midnorthern latitudes, is at an altitude of between 80 and 88 degrees (depending on how far north or south you are in the lower 48 states).
For Southern Hemisphere observers, the austral winter will mean the moon appears higher in the sky when it crosses the meridian. Skywatchers in Sydney will see the nearly full moon rise at 6:17 p.m. on Aug. 26, and it will cross the meridian at 12:04 a.m. on Aug. 27 at an altitude of about 68 degrees, as opposed to about 39 degrees in New York.
The August full moon is often called the Sturgeon Moon, according to the Old Farmer's Almanac, because sturgeon (a type of fish) are more easily caught in August and early September. Sturgeon are native to both Europe and the Americas; the name likely came from both colonists and Algonquian-speaking people in northeastern North America.
However, not every nation in the region called it that. The Ojibwa — who lived in what is now southeastern Canada, near the Great Lakes — referred to the eighth moon of the year as the Blackberry Moon, which could also occur in July. The August full moon — the ninth full moon of the year — was called the Corn Moon by peoples in northeastern North America, per the Old Farmer's Almanac. The eighth full moon, usually occurring in August, was called the Full Sturgeon Moon because that species was more easily caught in late summer (the August full moon happens to be the ninth in 2018 because there were two full moons in January).
The Cree of Ontario called the August full moon the Flying Up Moon because it was when young birds would fledge. In the Pacific Northwest, the Haida called it the Salmon Moon ("chíin kungáay"), according to Dolly Garza's book "Tlingit Moon & Tide."
In China, the seventh lunar month (which, in 2018, is August; it shifts from year to year) is when the Ghost Festival occurs. In 2018, it starts on Aug. 25. The Ghost Festival is celebrated during the seventh lunar month, often called the Ghost Month, on the 15th day, coinciding with the full moon. In Buddhist and Taoist traditions ghosts of people who were not given proper respects when they died return. People make burnt offerings – commonly fake bank notes. Sometimes lotus-shaped lanterns are lit and sent into lakes and rivers to float and guide souls to the afterlife.
For Muslims, the August full moon comes halfway through the month of Dhu'l-Hijja, the last month of the Islamic calendar. The days prior to that full moon (Aug. 19 to 23) are when devout Muslims are required to make the pilgrimage to Mecca, known as the hajj.
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- Jesse Emspak, Space.com Contributor
Jesse Emspak is a contributing writer for Live Science, Space.com and Toms Guide. He focuses on physics, human health and general science. Jesse has a Master of Arts from the University of California, Berkeley School of Journalism, and a Bachelor of Arts from the University of Rochester. Jesse spent years covering finance and cut his teeth at local newspapers, working local politics and police beats. Jesse likes to stay active and holds a third degree black belt in Karate, which just means he now knows how much he has to learn.
- Jesse Emspak, Space.com Contributor on