Southern Skywatch September 2021 edition is now out!

Evening sky on Thursday, September 10 showing the western sky as seen from Adelaide at 18:58 ACST (60 minutes after sunset). Venus is close to the crescent Moon with the bright star Spica and Mercury below.

 (similar views will be seen Australia wide at the equivalent local time, 60 minutes after sunset)

The September edition of Southern Skywatch is now up. 

This month the planetary action is mostly in the evening skies, with 4 bright planets visible after the sky is fully dark, with the pair of Venus and Mercury in the east and the pair of Saturn and Jupiter (just after opposition) in the west, the Moon meets Mercury and bright Venus. Mercury is at its best this month. For most of September Mercury, Venus and Spica make a nice line in the late evening twilight.

September 6; Venus and the bright star Spica close. September 7; New Moon. September 9; thin crescent Moon and Mercury close. September 10; thin crescent Moon and Venus close. September 11; perigee Moon. September 14; First Quarter Moon, September 16; the Moon close to Saturn. September 17; the Moon between Saturn and Jupiter. September 18; the waxing moon is near Jupiter. September 21; Full Moon. September 21; Mercury near Spica. September 23; Earth at Equinox. September 24; Venus near Zubenelgenubi. September 27; apogee Moon. September 29; Last Quarter Moon.

 Mercury  is readily visible in the early evening and is at its best for 2021 this month. On the 1st Mercury is just under a hand-span from the western horizon an hour and a half after sunset, with Venus and Spica above. during most of the month the three are in a line up, with Venus and Spica changing places. On the 9th Mercury is not far from the thin crescent Moon. On the 15th Mercury is just over a hand-span from the western horizon an hour and a half after sunset. Mercury moves closer to Spica and the pair are just a bit over a finger-width apart apart on the 21st. By the 30th Mercury is just under a hand-span from the western horizon an hour after sunset, not far from Spica with Venus above.

Venus is now easily visible in the evening sky from 30 minutes after sunset (I can see it as early as 5 minutes after sunset) until well after the sky is fully dark. Mercury, Venus and Spica make a nice line in the late evening twilight. At astronomical twilight, we can enjoy the sight the sight of bright Venus in the west mirroring bright Jupiter in the east Venus dominates the evening twilight as it comes closer to, and then passes, the bright star Spica. Venus now a distinct “gibbous Moon” shape. Venus is closest to Spica on the 6th (about one and a half finger widths). On the 10th Venus is close to the thin crescent Moon. The pair fit into the field of view of a 10×50 binoculars. Venus is close to the bright star Zubenelgenubi in Libra on the 24th. The pair fit in a the field of view of 10×50 binoculars. Zubenelgenubi is a double star and both stars will be seen in binoculars. With the pair of Mercury and Spica below, and red Antares above this will be an excellent sight around an hour after sunset.

Mars is lost in the twilight

Jupiter is readily visible from astronomical twilight and continues to climb into the evening sky. Jupiter was at opposition, when it was biggest and brightest as seen from Earth, on August 19th, but is still bright and an excellent object in even small telescopes. This month at astronomical twilight, we can enjoy the sight the sight of bright Venus in the west mirroring bright Jupiter in the east. Indeed mid month we have the pair of bright Venus and Mercury in the West and the pair of Saturn and Jupiter in the east when the sky is fully dark. Once Venus has set Jupiter dominates the night sky. On the 16th the waxing moon forms a line with Saturn and Jupiter. On the 17st the moon is between Jupiter and Saturn, but close to Saturn. On the 18th the waxing moon is close to Jupiter and the pair fit into the FOV of 10×50 binoculars. Then on the 19th the waxing moon again forms a line with Jupiter and Saturn. Telescopically Jupiter will be best late evening to the early morning when it is highest above the northern horizon.

Saturn can be easily seen from astronomical twilight (an hour and a half after sunset) during September. Saturn was at Opposition, when it was biggest and brightest as seen from Earth, on the 2nd od August. However it will remain great viewing for many weeks to come. On the 16th the waxing moon forms a line with Saturn and Jupiter. On the 17st the moon is between Jupiter and Saturn, but close to saturn. On the 18th the waxing moon is close to Jupiter and the pair fit into the FOV of 10×50 binoculars. Then on the 19th the waxing moon again forms a line with Jupiter and Saturn. The beginning of the month Saturn should be best for scopes around 9 pm local time (it will be good before then, but it is better when it is highest and in still air). As the month goes on Saturn rises earlier and it and Jupiter are prominent below the teapot of Sagittarius.

September 11; perigee Moon. September 27; apogee Moon.