| The Magazine of the CALIFORNIA ACADEMY OF SCIENCES |
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Skyguide
Bing F. Quock July 10 New Moon at 3:27 a.m. By sunset at 8:33 p.m., the Moon will be a gorgeous, 17-hour-old crescent low in the west-northwest. Binoculars should improve viewing. July 16 On this day 33 years ago, humans blasted off from the Earth on a 250,000-mile journey to the Moon, where they would leave their footprints four days later. The Sea of Tranquility, where they landed, is visible as the center of a row of three dark patches on the illuminated eastern half of the Moon’s face. In the absence of eroding atmosphere or water, the astronauts’ footprints will survive for billions of years. July 24 Full Moon, known to the Choctaw as the “Crane Moon.” In medieval England, this was the “Mead Moon,” while the Chinese named it the “Hungry Ghost Moon.” Tonight, it’s located against the stars of the constellation Capricornus. August 8 New Moon. Tomorrow night’s visible crescent will be a lovely sight next to elusive Mercury, both low in the west after sunset. August 12 Peak of the annual Perseid meteor shower, typically one of the year’s best and the most popular for observers in the Northern Hemisphere. This year, it coincides with a waxing crescent Moon that sets at 10:54 p.m., so moonlight won’t interfere between midnight and dawn—the optimum time to view the shower. The traditional peak occurs during daylight hours on the 12th, but a possible new peak around 1 a.m. on the morning of the 13th may favor observers in North America. August 22 Full Moon in the constellation Aquarius. The Cherokee called this the “Fruit Moon,” the Dakota Sioux the “Moon When All Things Ripen.” September 6 New Moon at 8:10 p.m. The first visible “young” crescent Moon won’t be seen until tomorrow evening. It will be the closest new moon this year to the Autumnal equinox. Sunset on the 7th will mark the start of Rosh Hashanah, the first day of the Jewish year 5763. September 21 Full Moon. As the nearest Full Moon to the September equinox, this is traditionally known as the “Harvest Moon.” Though some cultures reserve the name for the Full Moon on or after the equinox. The Chinese, having used the name “Harvest Moon” for the Full Moon of the eighth month, called this one the “Chrysanthemum Moon.” September 22 The Autumnal equinox, or the start of Fall at 9:56 p.m., for the Northern Hemisphere. The Sun rises due east and sets due west, theoretically spending equal amounts of time above and below the horizon. In the Southern Hemisphere, this is the beginning of Spring. The Planets Mercury In early July, the swiftest planet is a morning object, but it quickly sinks into the glow of the rising Sun. It disappears from view by about mid-month. It emerges in the evening sky in mid-August, but is visible only briefly, since the angle of the ecliptic (its apparent arc against the stars) is quite shallow with respect to the horizon. The planet’s path is very low, and Mercury never gets far enough from the Sun to be easily seen before it sets. Look for a very close conjunction with Saturn in the morning sky on July 1. The Moon swings nearby on the morning of July 9 and on the evenings of August 9 and September 8. Although at greatest eastern elongation on September 1, the shallow angle of the ecliptic makes this a poor opportunity to view this elusive little world. Venus The brightest of the planets is in the evening sky all season—watch it edge slowly southward along the horizon at sunset, passing the bright star Regulus (the heart of Leo) on July 9, then Spica in Virgo on August 31. The crescent Moon passes by for visits on the evenings of July 12 and 13, August 11, and September 9. Mars Soon after sunset on July 1, look for Mars and Jupiter together very low in the west-southwest. This season, Mars and Earth are on opposite sides of the Sun, so the Red Planet is hidden in our star’s glare nearly the whole time. The Moon swings nearby—but is difficult to see—on the evening of July 10 and on the mornings of August 8 and September 6. Jupiter The “King of the Planets” is not visible in July as it passes conjunction with the Sun on the 20th. Like Mars, it’s on the other side of the Sun, lost in its glare until about mid-August, when it rises into the predawn sky against the stars of Cancer. It’s close to the Moon on the mornings of August 7 and September 4. Saturn The “Ringed Planet” slowly lumbers toward the eastern boundary of Taurus, passing the star Zubenel genubi (the tip of the bull’s southern horn) in early August. Look for the Moon nearby on the mornings of July 8, August 4 and 5, and September 1. Those with medium-sized telescopes can find Saturn and the faint Crab Nebula, the remnant of an exploded star, together just before dawn on July 25.
Times are for San Francisco, California, and are accurate to within two minutes.
Bing F. Quock is Assistant Chairman of the Morrison Planetarium. bquock@calacademy.org |