The moon is one day past full, so rises about an hour after sunset. Neptune is 1.4 degrees north, which is an occultation for the extreme south (Antarctica). On Sept. 4, Jupiter is three degrees west of the moon in the eastern evening sky, and Uranus is just 1.2 degrees south. Plus, a day later, the moon is among the stars of the Seven Sisters (the Pleiades, M45). On the evening of Sept. 9, Pollux is 1.5 degrees north. The moon is new Sept. 14 and Sept. 16 and Mars is less than a degree south — another occultation — this one would be visible in all of North America, but it occurs during daylight. Later in the evening, find a clear western horizon and use binoculars or a telescope to see the ruddy Mars next to the moon. Sept. 21, Antares is occulted in the Eastern Hemisphere, less than a degree away from the first-quarter moon for Western viewers. By Sept. 26, Saturn is just three degrees north of the waxing gibbous moon in the southern sky. Just before full moon Sept. 29th, Neptune is once again occulted for the extreme south.
Mercury is at inferior conjunction Sept. 6, reappearing in mid-month for the best apparition for northern viewers. The speedy planet reaches its greatest elongation west in the early eastern sky Sept. 18, with Venus just to the northwest. Regulus in Leo, the Lion, is in between the two planets on that day.
Venus is stationary Sept. 2, meaning it stops prograde motion (eastward) and then slowly appears to move westward. Don’t forget that it’s an illusion resulting from Earth’s motion combined with the speedier Venus. The moon is in the same part of the sky Sept. 11.
Mars is increasingly difficult to find in the western evening sky. Sept. 16, as noted above, during daylight, the moon occults the Red Planet. A telescope is required to take in the event.
Jupiter is stationary Sept. 4, beginning retrograde motion, which keeps the giant planet in the sky for most of the night – a good viewing opportunity during September. On that night, Jupiter is three degrees southwest of the waning gibbous moon, with Uranus just south of the moon.
Saturn rises in the early evening amid the stars of Aquarius, providing a good view all through the night. If you have access to a telescope, now is the time to get out under the stars and take in the sights. Saturn and its rings, framed against the blackness of space, is an awesome sight.
Uranus on Sept. 4 is joined by the moon and Jupiter in the evening sky, rising about 10 p.m. local time. This planet is also retrograding among the stars of Aries.
Neptune is at opposition Sept. 19. It’s four light-hours from Earth, among the stars of Pisces.
The zodiacal light is visible before eastern morning twilight for the first two weeks of the month.
The autumnal equinox occurs in the very early morning of Sept. 23.
James Edgar has had an interest in the night sky all his life. He joined the Royal Astronomical Society of Canada in 2000, was national president for two terms, is now the editor of the Observer’s Handbook, and production manager of the bi-monthly RASC Journal. The IAU named asteroid 1995 XC5 “(22421) Jamesedgar” in his honour and in 2021 he was awarded a Fellowship of the RASC.
