Astroblog

The Full Moon is Tuesday, September 21.  Earth is at Equinox on the 23rd. Four bright planets are seen in the early evening sky. Venus and Mercury are readily visible in the evening sky. Mercury, the bright star Spica and Venus from a line in the late evening twilight. Saturn and Jupiter are visible in the evening sky with Jupiter dominating once Venus has set. The Moon is between Saturn and Jupiter on the 17th and close to Jupiter on the 18th.

The Full Moon is Tuesday, September 21. Earth is at Equinox on the 23rd, where day and night are nearly equal.

Evening twilight sky on Tuesday, September 21 looking north-west as seen from Adelaide at 19:06 ACST (60 minutes after sunset). Venus is high above the horizon with Mercury below close to the bright star Spica. 


The inset show the telescopic view of Venus and Mercury at this time. Similar views will be seen throughout Australia at the equivalent local time (60 minutes after sunset, click to embiggen).

 

Evening sky on Saturday, September 18 showing the north-eastern sky as seen from Adelaide at 19:33 pm ACST(90 minutes after sunset). The waxing Moon, Saturn and Jupiter form a line in the  evening sky with the Moon close to Jupiter. 

 

 The insets shows the telescopic views of Jupiter and Saturn at this time. Similar views will be seen elsewhere in Australia at the equivalent local time (90 minutes after sunset), click to embiggen.

 

Whole sky at 19:33 ACST  (90 minutes after sunset), on Saturday, September 18 as seen from Adelaide.  For bright planets can be seen in the sky.

 

 

 

 

Similar views will be seen elsewhere at the equivalent local time (90 minutes after sunset). 

 Mercury  is now high in the twilight. Mercury, Spica and Venus make a line in the late evening twilight and mercury comes closer to Spica. Mercury is closest to Spica on the 21st.

Venus is visible in the early evening when the sky is fully dark.  I have been able to see Venus from just after sunset and it is easily seen over 2 hours after sunset, longer if you have a clear western horizon.  When the sky is fully dark you can see Venus above the western horizon and bright Jupiter above the eastern horizon.

Labels: weekly sky

The First Quarter Moon is Tuesday, September 14.  Four bright planets are seen in the early evening sky. Venus and Mercury are readily visible in the evening sky. Mercury, the bright star Spica and Venus from a line in the late evening twilight. Venus is close  to the thin crescent Moon on the 10th. Saturn and Jupiter are visible in the evening sky with Jupiter dominating once Venus has set. Venus is seen in the west and Jupiter in the east when the sky is fully dark.

The First Quarter Moon is Tuesday, September 14. The Moon is at perigee, when it is closest to the Earth, on the 11th.

Evening twilight sky on Friday, September 10 looking north-west as seen from Adelaide at 19:27 ACST (90 minutes after sunset). Venus is high above the horizon close to the crescent moon with Mercury below. Mercury, Venus and the bright star Spica are from a line.


The inset show the telescopic view of Venus at this time. Similar views will be seen throughout Australia at the equivalent local time (90 minutes after sunset, click to embiggen).

Evening sky on Thursday, September 16 showing the north-eastern sky as seen from Adelaide at 19:32 pm ACST(90 minutes after sunset). The waxing Moon, Saturn and Jupiter form a line in the  evening sky. 

 

 

The insets shows the telescopic views of Jupiter and Saturn at this time. Similar views will be seen elsewhere in Australia at the equivalent local time (90 minutes after sunset), click to embiggen.

Whole sky at 19:28 ACST  (90 minutes after sunset), on Saturday, September 11 as seen from Adelaide.  For bright planets can be seen in the sky.

 

 

 

 

Similar views will be seen elsewhere at the equivalent local time (90 minutes after sunset). 

 Mercury  continues to climb rapidly in the twilight. Mercury, Spica and Venus make a line in the late evening twilight. Mercury is close to the Moon on the 9th.

Venus is visible in the early evening when the sky is fully dark.  I have been able to see Venus from just after sunset and it is easily seen over 2 hours after sunset, longer if you have a clear western horizon.  When the sky is fully dark you can see Venus above the western horizon and bright Jupiter above the eastern horizon. On the 10th Venus is close to the the crescent Moon. The pair fit into the field of view of a 10x50 binoculars.

Labels: weekly sky

Date	Brightness	Start			Highest point			End			Pass type
	(mag)	Time	Alt.	Az.	Time	Alt.	Az.	Time	Alt.	Az.
02 Sep	-0.7	20:04:08	10°	SSW	20:04:15	11°	SSW	20:04:15	11°	SSW	visible
03 Sep	-1.7	19:17:32	10°	S	19:19:24	17°	SSE	19:19:24	17°	SSE	visible
04 Sep	-1.4	18:31:23	10°	S	18:32:40	12°	SSE	18:33:56	10°	SE	visible
04 Sep	-1.2	20:06:28	10°	SW	20:07:40	20°	SW	20:07:40	20°	SW	visible
05 Sep	-3.6	19:19:27	10°	SW	19:22:49	51°	SE	19:23:03	50°	ESE	visible
06 Sep	-2.6	18:32:36	10°	SSW	18:35:39	29°	SE	18:38:34	11°	E	visible
06 Sep	-1.1	20:09:46	10°	WSW	20:11:37	19°	WNW	20:11:37	19°	WNW	visible
07 Sep	-2.4	19:22:10	10°	WSW	19:25:22	37°	NW	19:27:18	19°	N	visible
08 Sep	-3.6	18:34:54	10°	SW	18:38:19	76°	NW	18:41:42	10°	NE	visible
09 Sep	-0.3	19:27:25	10°	WNW	19:27:38	10°	NW	19:27:50	10°	NW	visible
10 Sep	-0.9	18:38:11	10°	W	18:40:40	19°	NW	18:43:09	10°	N	visible

Passes from Sydney (AEST)

Date	Brightness	Start			Highest point			End			Pass type
	(mag)	Time	Alt.	Az.	Time	Alt.	Az.	Time	Alt.	Az.
02 Sep	-1.5	18:56:39	10°	S	18:58:14	15°	SSE	18:58:14	15°	SSE	visible
03 Sep	-1.3	18:10:43	10°	SSE	18:11:25	10°	SSE	18:12:05	10°	SE	visible
03 Sep	-1.1	19:45:24	10°	SW	19:46:23	18°	SW	19:46:23	18°	SW	visible
04 Sep	-3.0	18:58:28	10°	SSW	19:01:38	36°	SE	19:01:38	36°	SE	visible
05 Sep	-2.2	18:11:43	10°	SSW	18:14:30	23°	SE	18:16:59	12°	E	visible
05 Sep	-1.3	19:48:18	10°	WSW	19:50:01	23°	W	19:50:01	23°	W	visible
06 Sep	-3.3	19:00:58	10°	SW	19:04:21	60°	NW	19:05:32	35°	NNE	visible
07 Sep	-3.7	18:13:51	10°	SW	18:17:17	70°	SE	18:20:40	10°	NE	visible
08 Sep	-0.9	19:04:30	10°	W	19:06:43	16°	NW	19:08:54	10°	NNW	visible
09 Sep	-1.7	18:16:43	10°	WSW	18:19:45	29°	NW	18:22:44	10°	NNE	visible

When and what you will see is VERY location dependent, so you need to use  Heavens Above  to get site specific predictions for your location, a small difference in location can mean the difference between the ISS passing over a star or planet or missing it completely. 

As always, start looking several minutes before the pass is going to start to get yourself oriented and your eyes dark adapted. Be patient, there may be slight differences in the time of the ISS appearing due to orbit changes not picked up by the predictions. Use the most recent prediction for your site.

Labels: ISS, Satellite, unaided eye

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 10x50 binoculars. Venus is close to the bright star Zubenelgenubi in Libra on the 24th. The pair fit in a the field of view of 10x50 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 10x50 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 10x50 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.

Labels: southern skywatch

The New Moon is Tuesday, September 7.  Venus is readily visible in the evening sky. Mercury continues to rise in the twilight. Mercury, Venus and the bright star Spica from a line in the late evening twilight. Venus is close to Spica on the 5th and 6th and Mercury is close to the thin crescent Moon on the 9th. Saturn and Jupiter are visible in the evening sky with Jupiter dominating once Venus has set. Venus is seen in the west and Jupiter in the east when the sky is fully dark.

The New Moon is Tuesday, September 7.

Evening twilight sky on Sunday, September 5 looking north-west as seen from Adelaide at 19:23 ACST (90 minutes after sunset). Venus is high above the horizon with Mercury low on the horizon. Mercury, Venus and the bright star Spica are close.



The insets show the telescopic view of Venus at this time. Similar views will be seen throughout Australia at the equivalent local time (90 minutes after sunset, click to embiggen).

 

Evening twilight sky on Thursday, September 9 looking north-west as seen from Adelaide at 19:27 ACST (90 minutes after sunset). Venus is high above the horizon with Mercury low on the horizon. Mercury, Venus and the bright star Spica from a line in the late evening twilight. Mercury is close to the Moon.

The insets show the telescopic view of Venus at this time. Similar views will be seen throughout Australia at the equivalent local time (60 minutes after sunset, click to embiggen).

 Evening sky on Saturday, September 4 showing the eastern sky as seen from Adelaide at 19:23 pm ACST(90 minutes after sunset). Saturn and Jupiter form a line in the  evening sky. 

 

 The insets shows the telescopic views of Jupiter and Saturn 8:15 ACST with Europa and its shadow transiting Jupiter's disk. Similar views will be seen elsewhere in Australia at the equivalent local time (90 minutes after sunset), click to embiggen.

 Whole sky at 19:23 ACST  (90 minutes after sunset), on Saturday, September 4 as seen from Adelaide.  For bright planets can be seen in the sky.

 

 

 

Similar views will be seen elsewhere at the equivalent local time (90 minutes after sunset). 

 

Mercury  continues to climb rapidly in the twilight. Mercury, Venus and Spica make a line in the late evening twilight. Mercury is close to the Moon on the 9th.

Venus is visible in the early evening when the sky is fully dark.  I have been able to see Venus from just after sunset and it is easily seen over 2 hours after sunset, longer if you have a clear western horizon.  When the sky is fully dark you can see Venus above the western horizon and bright Jupiter above the eastern horizon. On the 6th Venus is close to the bright star Spica

Labels: weekly sky

The Last Quarter Moon is Monday, August 30.  Venus is readily visible in the evening twilight. Mercury continues to rise in the twilight. Mercury, Venus and the bright star Spica from a line in the late evening twilight. Saturn and Jupiter are visible in the evening sky. Venus is seen in the west and Jupiter in the east when the sky is fully dark.

The Last Quarter Moon is Monday, August 30. The Moon is at apogee, when it is furthest from the earth, on the 30th.

Evening twilight sky on Saturday, August 28 looking north-west as seen from Adelaide at 18:49 ACST (60 minutes after sunset). Venus is high above the horizon with Mercury low on the horizon. Mercury, Venus and the bright star Spica from a line in the late evening twilight. Mercury is close to the star Beta Virginis.

The insets show the telescopic view of Venus at this time.  Similar views will be seen throughout Australia at the equivalent local time (60 minutes after sunset, click to embiggen).

Evening sky on Saturday, August 28 showing the eastern sky as seen from Adelaide at 19:18 pm ACST (90 minutes after sunset). Saturn and Jupiter form a line in the  evening sky. Jupiter was at Opposition, when it was biggest and brightest as seen from Earth on the 19th.

Whole sky at 19:18 ACST  (90 minutes after sunset), on Saturday, August 28 as seen from Adelaide. 

Labels: weekly sky

 It's National Science Week this week (well, it started Sunday, but I was too busy astrophotographing to write about it). While there are not as many in-person activities this year due to COVID, there are heaps of virtual activities to participate in. You can search for a local activity here. You can keep up with the latest developments at the Science Week blog. You can find a diary of events here as well. you can also catch special shows like The Chemical World on iView. Why not follow National Science Week on twitter @Aus_ScienceWeek

Labels: science week