Garrett County Skies

By Dr. Bob Doyle, Frostburg State Planetarium

          Harvest Moon on September 16 & Venus emerges from western dusk

SUN & MOON:  As September opens, the sun is in Leo. Around September 17, the sun moves into Virgo. Virgo is the widest zodiac group; the sun takes about six weeks to cross Virgo. (The Earthís motion about the sun makes it appear that the sun is moving eastward about 1 degree each day in front of the stars.)  At the start of September, Oaklandís sunrise is 6:46 a.m. with sunset at 7:49 p.m.  Fall begins on September 22 when the sunís vertical rays cross the Equator moving South. On this day, the sun shines equally on the North and South hemispheres. The sun rises due East and sets due West over much of the world at the start of fall and spring.  On September 26, both sunrise and sunset are at 7:09, with day and night each 12 hours. The end of September has sunrise at 7:13 a.m. and sunset at 7:02 p.m. So in September, we lose 1.2 hours of daily sunlight, the biggest drop of any month.  September opens and ends with a New Moon. On September 3rd,  a slender crescent moon will appear near the brilliant planet Venus very low in the western dusk.  On September 8, the nearly half full moon appears above the planet Saturn in the southwestern evening sky. On September 9, the evening moon appears half full (First Quarter), with itís  right side lit by the sun and the left side in lunar night. The straight line between bright and dark areas on the moon is called the terminator, where the sun is rising on the lunar surface. Here the crater rims and mountain ridges catch the sunís rays. On this same evening, the moon appears above the yellowish planet Mars. The Harvest Moon (full moon closest to the start of fall) is on September 16. As the moon slides East and North, it rises about half hour later each night, bringing extra evening moonlight on the following 3-4 nights. Colonial farmers could gather their last remaining crops in the early evening by moonlight. In the late evening hours of September 21, the moon appears very close to Aldebaran, the bright star marking Taurusí eye. On September 23, the moon appears half full in the southern dawn (Last Quarter). At monthís end, the moon disappears at dawn (New Moon).

PLANETS THIS MONTH:  At the start of September, the brilliant planet Venus can be seen within a half hour of sunset. During September, Venusí angle to the sun grows so by monthís end, Venus will be higher and easier to spot in the western dusk.  Jupiter is at too low an angle to the sun to be visible. Yellowish Mars and Saturn are in the Southwest in the early evening. At the start of September, Mars, Saturn and the bright star Antares form a triangle easily seen. But during September, Mars moves eastward among the stars and the triangle gets stretched. The planet Mercury can be seen low in the eastern dawn at monthís end.

STARS IN THE  EVENING AND AT DAWN:  In the evening, the Big Dipper with its seven moderately bright stars is striking in the North Northwest. The Dipperís handle extended to the left brings you to the bright golden star Arcturus (means Ďbear driverí). The two lowest stars of the Dipperís scoop points rightward  to the North Star.  Nearly overhead at twilight is the bright white-blue star Vega,now the brightest star in view. Late in the evening, the 7 Sisters star cluster can be seen low in the East. This star cluster, resembling a tangle of fireflies, was used by many early cultures to set their calendars.

The Frostburg State Planetarium will resume itís weekly public planetarium presentations. Shows are on Wednesday at 6 p.m. and 7 p.m. The Planetarium is in room 186 of the Gira Center. The Cumberland Astronomy Club will meet on Friday, September 15 at 7:30 p.m. Besides a discussion of sky events, there will be a video on the Hubble Space Telescope. All interested are welcome to attend.