Astroblog: September 2021

The New Moon is Wednesday, October 6. Four bright planets are seen in the early evening sky. Venus and Mercury are readily visible in the early evening sky at the beginning of the week but Mercury is rapidly lost to view. Saturn and Jupiter are visible in the evening sky with Jupiter dominating once Venus has set.

The New Moon is Wednesday, October 6.

Evening twilight sky on Saturday, October 2 looking west as seen from Adelaide at 19:15 ACST (60 minutes after sunset).

The inset shows 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, October 2 showing the north-eastern sky as seen from Adelaide at 19:45 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 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 19:45 ACST (90 minutes after sunset), on Saturday, October 2 as seen from Adelaide. Three 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 lowering in the twilight and will be difficult to see by the weeks end.

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 north-eastern horizon. Venus is below the head of the Scorpion making a rather beautiful sight in the early evening.

Mars is lost in the twilight.

Jupiter is now rising before sunset and is readily visible when the sky is fully dark. Saturn and Jupiter form a line in the sky. Jupiter was at Opposition, when it was biggest and brightest as seen from Earth on August the 19th, and is still excellent in even small telescopes.

Saturn is now rising well before sunset. Saturn was at opposition, when it is biggest and brightest as seen from Earth, on August 2nd. But it is still is an excellent time for telescopic observation.

Printable PDF maps of the Western sky at 10 pm AEST, Western sky at 10 pm AEST. For further details and more information on what's up in the sky, see Southern Skywatch.

Star Map via Virtual sky. Use your mouse to scroll around and press 8 when your pointer is in the map to set to the current time.

Cloud cover predictions can be found at SkippySky.

Here is the near-real time satellite view of the clouds (day and night) http://satview.bom.gov.au/

Labels: weekly sky

# posted by Ian Musgrave @ 11:43 pm 0 comments

The Last Quarter Moon is Wednesday, September 29. 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 bright double star α₂ Librae (Zubenelgenubi) on the 24th. Saturn and Jupiter are visible in the evening sky with Jupiter dominating once Venus has set.

The Last Quarter Moon is Wednesday, September 29. The moon is at apogee, when it is furthest from the earth, on the 27th.

Evening twilight sky on Friday, September 24 looking west as seen from Adelaide at 19:38 ACST (90 minutes after sunset). Venus is close to the bright double star α₂ Librae (Zubenelgenubi) with Mercury below near to the bright star Spica.

The inset shows the telescopic view of Venus and Mercury at this time, and a binocular view of Venus and α₂ Librae. Similar views will be seen throughout Australia at the equivalent local time (90 minutes after sunset, click to embiggen).

Evening sky on Saturday, September 25 showing the north-eastern sky as seen from Adelaide at 19:38 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 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 19:38 ACST (90 minutes after sunset), on Saturday, September 25 as seen from Adelaide. Four 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. Spica, Mercury and Venus make a line in the late evening twilight with mercury just above Spica.

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. Venus is close to the bright double star α₂ Librae (Zubenelgenubi) on the 24th. Venus and the paired stars are easily visible in binoculars together.

Mars is lost in the twilight.

Jupiter is now rising before sunset and is readily visible when the sky is fully dark. Saturn and Jupiter form a line in the sky. Jupiter was at Opposition, when it was biggest and brightest as seen from Earth on August the 19th, and is still excellent in even small telescopes.

Saturn is now rising now rising well before sunset. Saturn was at opposition, when it is biggest and brightest as seen from Earth, on August 2nd. But it is still is an excellent time for telescopic observation.

Printable PDF maps of the Eastern sky at 10 pm AEST, Western sky at 10 pm AEST. For further details and more information on what's up in the sky, see Southern Skywatch.

Star Map via Virtual sky. Use your mouse to scroll around and press 8 when your pointer is in the map to set to the current time.

Cloud cover predictions can be found at SkippySky.

Here is the near-real time satellite view of the clouds (day and night) http://satview.bom.gov.au/

Labels: weekly sky

# posted by Ian Musgrave @ 12:44 am 0 comments

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. Four 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.

Mars is lost in the twilight.

Jupiter is now rising before sunset and is readily visible when the sky is fully dark. Saturn and Jupiter form a line in the sky. Jupiter was at Opposition, when it was biggest and brightest as seen from Earth on August the 19th, and is still excellent in even small telescopes. On the 18th the Moon is close to Jupiter

Saturn is now rising around well before sunrise. Saturn was at opposition, when it is biggest and brightest as seen from Earth, on August 2nd. But it is still is an excellent time for telescopic observation. On Thursday 17th the waxing Moon is between Saturn and Jupiter.

Printable PDF maps of the Eastern sky at 10 pm AEST, Western sky at 10 pm AEST. For further details and more information on what's up in the sky, see Southern Skywatch.

Star Map via Virtual sky. Use your mouse to scroll around and press 8 when your pointer is in the map to set to the current time.

Cloud cover predictions can be found at SkippySky.

Here is the near-real time satellite view of the clouds (day and night) http://satview.bom.gov.au/

Labels: weekly sky

# posted by Ian Musgrave @ 3:19 am 0 comments

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.

Mars is lost in the twilight.

Jupiter is now rising before sunset and is readily visible when the sky is fully dark. Saturn and Jupiter form a line in the sky. Jupiter was at Opposition, when it was biggest and brightest as seen from Earth on August the 19th, and is still excellent in even small telescopes.

Saturn is now rising around well before sunrise. Saturn was at opposition, when it is biggest and brightest as seen from Earth, on August 2nd. But it is still is an excellent time for telescopic observation.On Thursday 16th the waxing Moon, Saturn and Jupiter form a line in the evening sky.

Printable PDF maps of the Eastern sky at 10 pm AEST, Western sky at 10 pm AEST. For further details and more information on what's up in the sky, see Southern Skywatch.

Star Map via Virtual sky. Use your mouse to scroll around and press 8 when your pointer is in the map to set to the current time.

Cloud cover predictions can be found at SkippySky.

Here is the near-real time satellite view of the clouds (day and night) http://satview.bom.gov.au/

Labels: weekly sky

# posted by Ian Musgrave @ 9:51 pm 0 comments


The ISS as seen from Brisbane on the evening of Wednesday 7 September at 18:18 AEST. Simulated in Stellarium (the ISS will actually be a bright dot), the white line is the path of the ISS, the other lines are paths of other satellites. Click to embiggen.	The ISS as seen from Adelaide on the evening of Tuesday 6 September at 18:33 ACST. Simulated in Stellarium (the ISS will actually be a bright dot), the white line is the path of the ISS, the other lines are paths of other satellites. Click to embiggen.	The ISS as seen from Perth on the evening of Tuesday 6 September at 18:37 AWST. Simulated in Stellarium (the ISS will actually be a bright dot), the white line is the path of the ISS, the other lines are paths of other satellites. Click to embiggen.

All sky chart showing local times from Heavens Above for Wednesday 7 September for Brisbane.	All sky chart showing local times from Heavens Above for Tuesday 6 September for Adelaide.	All sky chart showing local times from Heavens Above for Tuesday 6 September for Perth.

If it is not bucketing down rain where you are, over the next few days there are a series of bright ISS passes in the late evening twilight/early evening. The ISS passes close to the the bright planets Jupiter and Saturn and not far from Venus on some occasions. With some bright passes through the heart of the Milky Way. There are also some bright passes where it "winks out" as the ISS enters Earth's shadow. As well there a number of passes close to bright stars.

The following tables are from data provided from Heavens Above. Particularly impressive passes are highlighted in yellow, passes entering the shadow in blue.

Passes from Adelaide (ACST)

Date	Brightness	Start			Highest point			End			Pass type
Date	(mag)	Time	Alt.	Az.	Time	Alt.	Az.	Time	Alt.	Az.	Pass type
01 Sep	-1.2	19:12:06	10°	S	19:13:10	11°	SSE	19:13:10	11°	SSE	visible
02 Sep	-1.1	20:00:19	10°	SSW	20:01:14	16°	SSW	20:01:14	16°	SSW	visible
03 Sep	-2.3	19:13:32	10°	SSW	19:16:23	24°	SSE	19:16:23	24°	SSE	visible
04 Sep	-1.7	18:26:53	10°	SSW	18:29:09	16°	SSE	18:31:23	10°	ESE	visible
04 Sep	-1.6	20:02:52	10°	SW	20:04:39	27°	WSW	20:04:39	27°	WSW	visible
05 Sep	-3.8	19:15:46	10°	SW	19:19:12	71°	SE	19:20:01	47°	ENE	visible
06 Sep	-3.1	18:28:49	10°	SSW	18:32:04	39°	SE	18:35:18	10°	ENE	visible
06 Sep	-1.1	20:06:23	10°	W	20:08:34	17°	NW	20:08:34	17°	NW	visible
07 Sep	-1.9	19:18:40	10°	WSW	19:21:42	30°	NW	19:24:16	13°	N	visible
08 Sep	-3.1	18:31:19	10°	SW	18:34:41	57°	NW	18:38:01	10°	NNE	visible
10 Sep	-0.8	18:34:49	10°	W	18:37:00	16°	NW	18:39:10	10°	NNW	visible

Passes from Brisbane (AEST)

Date	Brightness	Start			Highest point			End			Pass type
Date	(mag)	Time	Alt.	Az.	Time	Alt.	Az.	Time	Alt.	Az.	Pass type
04 Sep	-1.4	19:00:35	10°	S	19:01:38	15°	S	19:01:38	15°	S	visible
05 Sep	-1.5	18:14:35	10°	SSE	18:15:53	12°	SE	18:16:59	10°	SE	visible
05 Sep	-0.5	19:49:36	10°	SW	19:50:01	13°	SW	19:50:01	13°	SW	visible
06 Sep	-3.6	19:02:28	10°	SW	19:05:32	64°	S	19:05:32	64°	S	visible
07 Sep	-3.0	18:15:36	10°	SSW	18:18:46	35°	SE	18:21:13	15°	ENE	visible
07 Sep	-0.4	19:53:44	10°	W	19:54:16	11°	WNW	19:54:16	11°	WNW	visible
08 Sep	-1.6	19:05:31	10°	WSW	19:08:20	24°	NW	19:10:09	16°	N	visible
09 Sep	-2.8	18:18:00	10°	SW	18:21:19	50°	NW	18:24:36	10°	NNE	visible

Passes from Darwin (ACT)

Date	Brightness	Start			Highest point			End			Pass type
Date	(mag)	Time	Alt.	Az.	Time	Alt.	Az.	Time	Alt.	Az.	Pass type
08 Sep	-2.3	20:11:19	10°	SSW	20:13:13	31°	SSW	20:13:13	31°	SSW	visible
09 Sep	-2.9	19:24:31	10°	SSW	19:27:36	31°	SE	19:29:20	19°	ENE	visible
10 Sep	-1.1	20:14:39	10°	WSW	20:17:06	19°	NW	20:18:43	14°	NNW	visible

Passes from Hobart (AEST)

Date	Brightness	Start			Highest point			End			Pass type
Date	(mag)	Time	Alt.	Az.	Time	Alt.	Az.	Time	Alt.	Az.	Pass type
01 Sep	-2.9	19:40:30	10°	SW	19:43:10	47°	SSW	19:43:10	47°	SSW	visible
02 Sep	-3.1	18:53:30	10°	SW	18:56:49	43°	SSE	18:58:14	27°	E	visible
02 Sep	-0.5	20:30:33	10°	WSW	20:31:14	14°	W	20:31:14	14°	W	visible
03 Sep	-2.9	19:43:16	10°	WSW	19:46:23	46°	NW	19:46:23	46°	NW	visible
04 Sep	-3.7	18:56:08	10°	WSW	18:59:35	79°	NNW	19:01:38	22°	NE	visible
05 Sep	-1.3	19:46:40	10°	W	19:49:00	17°	NW	19:50:01	15°	NNW	visible
06 Sep	-1.8	18:59:05	10°	WSW	19:02:04	28°	NW	19:05:01	10°	NNE	visible
07 Sep	-2.6	18:11:45	10°	WSW	18:15:04	45°	NW	18:18:21	10°	NE	visible

Passes from Melbourne (AEST)

Date	Brightness	Start			Highest point			End			Pass type
Date	(mag)	Time	Alt.	Az.	Time	Alt.	Az.	Time	Alt.	Az.	Pass type
01 Sep	-1.8	19:41:18	10°	SSW	19:43:10	21°	S	19:43:10	21°	S	visible
02 Sep	-1.8	18:54:31	10°	SSW	18:56:58	18°	SSE	18:58:14	15°	SE	visible
02 Sep	-0.5	20:30:42	10°	SW	20:31:14	14°	SW	20:31:14	14°	SW	visible
03 Sep	-3.1	19:43:39	10°	SW	19:46:23	48°	SSW	19:46:23	48°	SSW	visible
04 Sep	-3.0	18:56:42	10°	SW	18:59:57	38°	SE	19:01:37	22°	E	visible
04 Sep	-0.5	20:33:57	10°	W	20:34:39	14°	W	20:34:39	14°	W	visible
05 Sep	-2.6	19:46:27	10°	WSW	19:49:40	37°	NW	19:50:01	36°	NNW	visible
06 Sep	-3.5	18:59:13	10°	SW	19:02:39	69°	NW	19:05:32	14°	NE	visible
07 Sep	-0.7	19:50:41	10°	WNW	19:51:58	12°	NW	19:53:14	10°	NNW	visible
08 Sep	-1.2	19:02:25	10°	W	19:05:02	20°	NW	19:07:38	10°	N	visible

Passes from Perth (AWST)

Date	Brightness	Start			Highest point			End			Pass type
Date	(mag)	Time	Alt.	Az.	Time	Alt.	Az.	Time	Alt.	Az.	Pass type
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
Date	(mag)	Time	Alt.	Az.	Time	Alt.	Az.	Time	Alt.	Az.	Pass type
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

# posted by Ian Musgrave @ 11:22 pm 1 comments