August’s main sky event promises to be our annual encounter with the tenuous trail of debris left in solar orbit by comet 109/P Swift-Tuttle. As Earth plows through this veil of mostly small grains and dust, we can see comet fragments appear as swift light traces of Perseid meteors.
The Perseid shower is the night of August 12/13. It peaks for viewers in the eastern United States during predawn hours of Thursday August 13 and the show should be better than usual because that night the Moon is new so lunar glow won’t wash out meteor trails of lesser brightness. Although Perseids arrive in greatest numbers early on the morning of the 13th, there’ll be a gradual lead-up during the previous several days and late arrivals may be spotted for several nights after the peak.
Try and get to a relatively dark location and prepare with bug repellent and a reclining chair. Refreshments and good company can add to the occasion, and although binoculars might be used occasionally—perhaps to examine lingering trails of bright fireballs, I prefer wider views provided by unaided eyes.
Meteor trails from the August 12/13 shower appear to originate at a vanishing point known as the radiant in the constellation Perseus. Stars of Perseus rise above the north-northeast horizon around 9 p.m. for observers in mid-northern latitudes, and about 4 a.m.—peak time in the eastern U.S, the radiant will be two-thirds of the way between horizon and zenith toward east-northeast. To see the entire flight of a meteor it’s usually best to look near the zenith, with a slight nod toward Perseus whence these meteors radiate. If you get to a reasonably dark location, one meteor per minute might be seen as the objects are heated to incandescence at altitudes of about 50 to 75 miles.
For folks who would like to delve into meteor observing, the American Meteor Society provides information and related activities. The Perseid shower is one of the best, and though its brightest examples may be seen even from a Manhattan sidewalk, the prime variable under your control for meteor watching is being at a darkest possible location. Attilla Danko’s Clear Dark Sky service provides a light pollution map linking charts and coordinates of relatively dark observing locales in a multi-state area centered on New York City, as well as similar information for other sites across North America.
Before I forget, there are two sky spectaculars you should add to your calendar. Next month we’ll have a triple header Full Moon spectacular. Sunday evening, September 27, it’s the night of Harvest Moon, and this year that harbinger of autumn is also a super Moon. The lunar disk will appear larger than average. And, as icing on the cake, that night we’ll also have a total lunar eclipse during evening hours for those in the Eastern Time zone, so alarm clocks won’t be needed for that event around here.
Looking even further ahead to August 21, 2017, a great total solar eclipse will sweep across the United States with a centerline of daytime darkness extending from the Oregon coast through Nebraska to Atlantic beaches of South Carolina. There are few events as marvelous as experiencing a total solar eclipse first hand. The 2017 eclipse will be a good opportunity for Andrea and I to visit her childhood home in the area of Roebuck, Moore, and Woodruff, near Spartanburg SC. If you expect to book lodgings at or near the centerline of totality, do so ASAP. After details start appearing in the media, lodging availability near the centerline of totality will begin to vanish. The NASA eclipse map can be clicked to show eclipse times at locations across the country. Start planning for the big day!
P.S. If you can’t connect with the Sun-Moon event of 2017, another total solar eclipse will be visible across the U.S. from Texas to Maine the afternoon of April 8, 2024.
The Moon
| Last Quarter | August 6 |
| New Moon | August 14 |
| First Quarter | August 22 |
| Full Moon | August 29 |
Planets
| Mercury | Sets 8:46 p.m. | Leo |
| Venus | Rises 6:27 a.m. | Leo |
| Mars | Rises 4:31 a.m. | Cancer |
| Jupiter | Sets 8:17 p.m. | Leo |
| Saturn | Sets 12:04 a.m. | Libra |
| Uranus | Rises 10:06 p.m. | Pisces |
| Neptune | Rises 8:30 p.m. | Aquarius |
Contrasting with June’s magnificent Venus/Jupiter planet encounter, during August all bright planets except Saturn seem to be on vacation and mainly out of sight. Jupiter might be glimpsed low in evening twilight for a few days at the start of the month, but Venus doesn’t escape the Sun’s glare and become visible in early morning twilight until the end of August. Throughout this month both Mercury and Mars are too close to the Sun for convenient viewing.
He’s back: early risers looking above the eastern horizon before morning twilight in August can again welcome magnificent stars comprising the constellation Orion. During predawn hours, artificial lighting in most locales is near minimum and, if your view is also east over the Atlantic, Orion rising is an especially dramatic sight.
With Orion in view on the early morning of August 8, the waning crescent moon forms a triangle with the two fine open stars clusters in Taurus, the Pleiades and Hyades. Members of this triad are beautiful sights in binoculars and low magnification telescopes.
August’s biggest sky show promises to be our annual encounter with the Perseid Meteor Shower during early morning hours of Thursday August 13.
On the evening of Wednesday the 19th, a waxing crescent Moon is just four degrees of arc from first magnitude Spica, brightest star in the constellation Virgo.
Saturday August 22, the first quarter Moon is three degrees from first magnitude Saturn. If you have a telescope, use it to view Saturn and its wonderful rings, that night the Moon is a sure guide to locating this spectacular planet.