The Sky This Week 2003 September 5 – 12
The Moon brightens the evening skies this week, sharing the limelight with brilliant Mars. The Full Moon occurs on the 10th at 12:36 pm Eastern Daylight Time. On the evening of the 5th the Moon sits just east of the teapot-shaped asterism of Sagittarius, the Archer. On the evenings of the 8th and 9th Luna flanks the warm pink glimmer of Mars.
September’s Full Moon is popularly known as the Harvest Moon. It gets this name from a curious bit of sky geometry which allows it to rise at nearly the same time each successive night around the time of Full Moon as seen from northern European latitudes. Here in Washington the shortest interval between moonrises at this time of year is about 24 minutes, but from the latitude of London it’s only a 15-minute difference. In places like Tromso, Norway it actually rises earlier each night! Since the nearly Full Moon rises close to the time of sunset, farmers of old could take advantage of the extra light it provided to give them a little more time to bring in their crops, and so the legend was born. The geometry of October’s Full Moon is similar, and it is still known as the Hunter’s Moon.
Despite a two-night engagement with the Moon, ruddy Mars is still the show-stopper of the late summer sky. The red planet now rises at around 7:30 pm and transits the meridian about 35 degrees up in the southern sky at around midnight. He has already faded by a couple of tenths of a magnitude from his record close approach of two weeks ago, but you’ll have no trouble picking him out in the late night sky. He’s still the brightest thing you’ll see after the Sun and Moon. Through a telescope he still sports a sizeable disc, and this week earthbound observers have a good view of his most prominent surface feature, discovered by Christiaan Huygens back in 1659.
Night owls and early risers can now catch a glimpse of Saturn in the wee hours. The ringed planet rises at around 1:30 am, and he’s well up in the east by the first light of dawn. He’s currently drifting slowly through the stars of Gemini, accompanied by the rest of the bright stars of the Great Winter Circle. If you’re up before the Sun, take a look at him through the telescope. By the time Mars has faded from his current notoriety, Saturn will be commanding our full attention.
