1 Moon passes Pluto
6 Full Moon – “Corn Moon” – passes Neptune
9 Moon passes Uranus
12 Moon passes Aldebaran
13 Last Quarter Moon at perigee (229,820 miles from Earth)
17 Moon passes Venus
18 Moon passes Mercury, Mars, and Regulus
20 New Moon determines the start of the Jewish High Holy Days, which begin that evening with Rosh Hashanah.
22 Moon passes Jupiter
26 Moon passes Saturn
27 First Quarter Moon at apogee (251,250 miles from Earth)
28 Moon passes Pluto
NEWS OF THE WORLD
Jupiter (mag.-1.7) is still visible in Virgo, though setting earlier (between 8 and 9 PM) as Earth leaves it behind. Saturn (mag.0.5) follows in Ophiuchus, setting around midnight.
Neptune (mag.7.8) reaches opposition on September 5, in Aquarius, and is visible all night, though it will be easier to spot as the Moon wanes. Uranus (mag.5.7) rises two hours later, in Pisces. Both can be seen in binoculars or a small telescope.
Most of the planetary action this month, however, is in the morning sky. Venus (mag.-3.9) rises a little after 4 AM, passing M44 (the Beehive Cluster in Cancer) on September 1-2, and then moving into Leo on the 10th, joining Mercury (mag.-0.4 ) which reaches its greatest elongation (18° west of the Sun) on September 12. Mars (mag.1.8) also appears in Leo this month, coming close to Mercury on September 1 and again on the 16th. On the 18th, all three planets are joined by the de-crescent Moon which rises around 5:30 AM.
The Autumnal Equinox occurs at 4:02 AM on September 22.