Skywatcher’s Guide (July–September 2014)
Earth at aphelion (greatest distance from the Sun)—152,093,481 kilometers/94,506,507 miles—showing that the seasons are not caused by Earth’s distance from the Sun but rather by the tilt of its axis of rotation. If its orbit were less circular and more elliptical, like that of Mars, it would be a different story. See August 17.
Moon at first quarter, lit from the right-hand side. As seen from the West Coast just after nightfall, it is nestled snugly between the red planet Mars and the bright star Spica in Virgo the Maiden.
Full moon in Capricornus the Sea Goat. Native Americans named this full moon the "Killer Whale Moon" (Haida), the "Crane Moon" (Choctaw), and the "Moon of the Giant Cactus" (Pima).
Last quarter moon for the Pacific time zone, where it occurs before midnight. In the Mountain, Central, and Eastern time zones, it occurs after midnight and so on the 19th. Either way, it rises tonight against the stars of Pisces the Fishes and is high in the southeast at dawn, lit from the left-hand side.
New moon. Sighting of the first thin crescent after new marks the start of the month Shawwal in the Islamic calendar. This will not be possible until after sunset on the 28th.
First quarter moon lit from the right-hand side and located in the southwest after sunset, visible only for the first half of the night.
Full moon in Aquarius the Water Carrier and a perigeal full moon—that is, a full moon occurring within a half hour of perigee (the Moon’s nearest approach to Earth), making this the closest and biggest looking full moon of the year and resulting in higher tides than usual. The full moon of August is also known to some Native American nations as the "Sturgeon Moon" (Algonquin), the "Time When the Cherries are Ripe" (Cheyenne), and the "Blueberry Moon" (Ojibway).
Peak of the annual Perseid meteor shower as Earth plows through the trail of dust left in the wake of Comet Swift-Tuttle, producing up to 80 meteors per hour radiating from the constellation Perseus the Hero. Unfortunately, the Moon is a waning gibbous—two days past full—and its bright light will obscure all but the brightest meteors from view during the post-midnight hours that are considered best for watching a shower.
Last quarter moon occurs during the predawn hours, when the Moon is in Taurus the Bull, lit from the left-hand side.
New moon. The first visible crescent after new marks the start of Dhul-Qi’dah, the 11th month of the Moon based Islamic calendar. This will be visible only from South America on the 26th and from most of the rest of the world including the U.S. on the 27th.
First quarter moon in Ophiuchus the Serpent Bearer, not one of the usual constellations of the Zodiac, but one which intrudes across the ecliptic (the Sun’s path against the stars) and where solar system objects spend more time than against the stars of neighboring Scorpius the Scorpion.
Full moon in U.S. time zones (some calendars written for Greenwich Time say this occurs on the 9th). Located against the stars of Aquarius the Water Carrier, rises at sunset and is visible all night. Although the full moon is supposedly fully illuminated and theoretically shadowless, some observers search for a hint of shadows along the edge of the Moon’s disk. September’s full moon was known to some Native American tribes as the "Wild Rice Moon" (Ojibway), the "Cool Moon" (Cheyenne), and the "Moon When the Plums are Scarlet" (Lakota Sioux). Being closest to the September Equinox, this moon is also called the "Harvest Moon" (details in Notes for This Season).
Last quarter moon for the Pacific and Mountain time zones (after midnight and so on the 16th for Central & Eastern. Rises at midnight against the stars of Taurus the Bull.
September equinox at 7:29 p.m. PDT. Sunrise and sunset are due east and west, respectively, and—at least in theory—day and night are of equal length. For observers located on Earth’s equator, the Sun passes directly overhead at noon. In the Northern Hemisphere, this is the beginning of fall. In the Southern Hemisphere, it's the beginning of spring.
New Moon (the 24th in all but the Pacific time zone). Sighting of the first crescent after new marks the start of the month Dhul-Hijjah in the Islamic calendar, not visible in the U.S. until the 25th, and not in the Middle East or Asia until the 26th.