Tiny Mercury begins this month’s planetary parade, peeking just above the southwestern horizon for a good part of the first half of this month. It reaches its maximum elevation of 4 degrees above the horizon from the 2nd through the 6th. Shinning at magnitude 0.0, it will still be difficult to find in the afterglow of sunset, so some good binoculars will no doubt aid your search.
Venus will be visible all month long above the southwestern horizon. Shining at magnitude -4.1, it will be hard to miss. You might also notice that the bright star Spica, in the constellation Virgo, is shining nearby. See if you can spot it about 1.5 degrees to the right of Venus. Mars is approaching conjunction with the Sun and is lost to our view for this month.
Our two gas giants, Jupiter and Saturn, will continue to dominate the evening sky. With Saturn leading, they will continue to slowly march westward in the southeastern sky. Except when visited by the very bright Moon on the 16th and 17th, both giant planets are well placed in the sky for small telescope viewing of their atmospheres and many moons. Saturn’s rings are still open at a good angle which permits viewing of their details. If you have a small to medium-sized telescope, see if you can spot the shadow of the rings on Saturn’s cloudy surface.
The Moon will be new on the 7th, first quarter on the 13th, full on the 20th, and last quarter on the 29th. Look to the west-southwest on September 8th and 9th about 30 minutes after sunset. On the 8th, the thin sliver of the new crescent Moon will be just above and to the right of tiny Mercury as the pair hovers just above the horizon. On the 9th, and again about 30 minutes after sunset, the crescent Moon will be slightly above and to the right of brilliant Venus.
Looking to the southeast on the 16th and 17th, about an hour after sunset, the waxing gibbous Moon will be just below the ringed planet Saturn on the 16th and just below and to the right of giant Jupiter on the 17th.
On September 22nd, at 01:20 p.m. MDT, we can welcome the Autumnal Equinox as the fall season officially begins.
Due to Covid-19 restrictions there will not be a first Saturday star party at the Etscorn Campus Observatory.
Jon Spargo, New Mexico Tech Astronomy Club