Astroblog: September 2025

The Full Moon is Tuesday October 7. This is a perigee ("super") Full Moon. Saturday 4th is International Observe the Moon Night. Daylight savings starts on the 5th. Mercury is low in the evening twilight. Mars is lowering in the evening sky as it heads towards Libra. Saturn is past opposition, but is still visible the entire night. It is close to the waxing Moon on the 5th and 6th. Jupiter is visible in the morning sky near the bright star Pollux. Venus is deep in the twilight.

The Full Moon is Tuesday October 7. This is a perigee full Moon, with perigee on the 8th. Saturday 4th is International Observe the Moon Night.

Western twilight sky on the evening of Saturday, October 4 as seen from Adelaide at 19:01 ACST (45 minutes after sunset, click to embiggen).

Mercury is climbing away from the bright star Spica low in the twilight. You will need a clear, level horizon to see them, and possibly binoculars.

Similar views will be seen from the rest of Australia at roughly the equivalent local time (45 minutes after sunset).

Western sky on Saturday, October 4 as seen from Adelaide at 19:47 ACST (90 minutes after sunset, click to embiggen). Comet C/2025 R2 (Swan) is in Libra above alpha Librae.. The inset is the approximate binocular view of the comet at the time.

Comet C/2025 R2 (Swan) is a recently discovered comet that is around magnitude 7 (binoculars only), but it is well placed near some very bright guide stars so it will be easy to find. It will brighten a bit as it climbs higher into the dark skies, but will not really reach visual magnitude.

More information and printable charts here. https://astroblogger.blogspot.com/2025/09/how-to-see-new-comet-c2025-r2-swan-from.html

Similar views will be seen from the rest of Australia at roughly the equivalent local time (90 minutes after sunset).

North-eastern twilight sky on the morning of Saturday, October 4 as seen from Adelaide at 04:53 ACST (60 minutes before sunrise, click to embiggen).

Jupiter is passing through Gemini and is near the bright star Pollux. Jupiter forms a triangle with the bright stars Procyon and Betelgeuse.

The inset is the telescopic view Jupiter at this time.

Similar views will be seen from the rest of Australia at roughly the equivalent local time (60 minutes before sunrise).

Eastern sky on the evening of Sunday, October 5 as seen from Adelaide at 20:47 ACDST (90 minutes after sunset, click to embiggen).

Saturn is just past at opposition, when it is biggest and brightest as seen from Earth. Saturn is visible all night long. Saturn is close to the waxing Moon (and also on the 6th).

The inset shows the telescopic view at this time.

Similar views will be seen from the rest of Australia at roughly the equivalent local time (90 minutes after sunset).

North-western sky on Saturday, Saturday, October 4 as seen from Adelaide at 19:16 ACST (60 minutes after sunset, click to embiggen). Mars is coming closer to Libra.

Similar views will be seen from the rest of Australia at roughly the equivalent local time (60 minutes after sunset).

Whole sky on Saturday, Saturday, October 4 as seen from Adelaide at 19:47 ACST, 90 minutes after sunset (click to embiggen). This is international observe the Moon night.

Mars is in the north-west. Saturn is in the east

Bright Achernar is rising from the Southern horizon. Scorpius is setting in the west and the galactic core is coming off the Zenith.

The Southern Cross is sinking in the Southern sky. The moon is full and the fainter clusters and nebula are hard to see.

Elsewhere in Australia will see a similar view at the equivalent time (90 minutes after sunset).

Mercury climbs higher in the evening twilight.

Venus is hard to see deep in the twilight glow.

Mars is passing through Virgo leaving the star Spica behind.

Jupiter climbs in the morning twilight. Jupiter forms a triangle with Procyon and Betelgeuse.

Saturn was at opposition, when it was biggest and brightest as seen from Earth on the 21st. Saturn is visible all night long and is close to the waxing Moon on the 5th and 6th.

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 @ 6:00 pm 0 comments

The First Quarter Moon is Monday September 30. Mercury returns to the evening twilight and is close to the star Spica on the 2nd. Mars is lowering in the evening sky as it heads towards Libra. Saturn is just past opposition, and is still visible the entire night. Jupiter is visible in the morning sky near the bright star Pollux. Venus is low in the twilight.

The First Quarter Moon is Monday September 30. The Moon is at apogee, when it is furthest from the Earth, on the 26th.

Western twilight sky on the evening of Thursday, October 2 as seen from Adelaide at 19:00 ACST (45 minutes after sunset, click to embiggen).

Mercury is close to the bright star Spica low in the twilight. You will need a clear, level horizon to see them, and possibly binoculars.

Similar views will be seen from the rest of Australia at roughly the equivalent local time (45 minutes after sunset).

North-western sky on Saturday, September 27 as seen from Adelaide at 19:35 ACST (90 minutes after sunset, click to embiggen). Comet C/2025 R2 (Swan) is just above Mars. The inset is the approximate binocular view of the comet at the time.

Comet C/2025 R2 (Swan) is a (very) recently discovered comet that is around magnitude 7 (binoculars only), but it is well placed near some very bright guide stars so it will be easy to find. It will brighten a bit as it climbs higher into the dark skies, but will not really reach visual magnitude.

For this week it is relatively low above the horizon, and sets an hour after astronomical twilight, so you have a narrow window to observe. More information and printable charts here. https://astroblogger.blogspot.com/2025/09/how-to-see-new-comet-c2025-r2-swan-from.html

Similar views will be seen from the rest of Australia at roughly the equivalent local time (90 minutes after sunset).

North-eastern twilight sky on the morning of Saturday, September 27 as seen from Adelaide at 05:03 ACST (60 minutes before sunrise, click to embiggen).

Jupiter is passing through Gemini and is near the bright star Pollux. Jupiter forms a triangle with the bright stars Procyon and Betelgeuse. Venus is right on the horizon.

The inset is the telescopic view Jupiter at this time.

Similar views will be seen from the rest of Australia at roughly the equivalent local time (60 minutes before sunrise).

Eastern sky on the evening of Saturday, September 27 as seen from Adelaide at 19:41 ACST (90 minutes after sunset, click to embiggen).

Saturn is just past at opposition, when it is biggest and brightest as seen from Earth. Saturn is visible all night long. The inset shows the telescopic view at this time.

Similar views will be seen from the rest of Australia at roughly the equivalent local time (90 minutes after sunset).

North-western sky on Saturday, September 27 as seen from Adelaide at 19:11 ACST (60 minutes after sunset, click to embiggen). Mars is drawing away from the bright star Spica.

Similar views will be seen from the rest of Australia at roughly the equivalent local time (60 minutes after sunset).

Whole sky on Saturday, September 27 as seen from Adelaide at 19:41 ACST, 90 minutes after sunset (click to embiggen).

Mars is in the north-west. Saturn is in the east

Bright Achernar is rising from the Southern horizon. Scorpius is setting in the west and the galactic core is coming off the Zenith.

The Southern Cross is sinking in the Southern sky. The moon is waxing and the fainter clusters and nebula are becoming harder to see.

Elsewhere in Australia will see a similar view at the equivalent time (90 minutes after sunset).

Mercury returns to the evening twilight twilight and is close to the star Spica on the 2nd.

Venus is hard to see deep in the twilight glow.

Mars is passing through Virgo leaving the star Spica behind.

Jupiter climbs in the morning twilight above Venus. Jupiter forms a triangle with Procyon and Betelgeuse.

Saturn was at opposition, when it was biggest and brightest as seen from Earth on the 21st. Saturn is visible all night long.

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 @ 6:00 pm 1 comments


North-western sky on Tuesday, September 17 as seen from Adelaide at 19:35 ACST (90 minutes after sunset, click to embiggen). Comet C/2025 R2 (Swan) is just above Mars. The inset is the approximate binocular view of the comet at the time.	North-western sky on Saturday, September 20 as seen from Adelaide at 19:35 ACST (90 minutes after sunset, click to embiggen). Comet C/2025 R2 (Swan) is just above Mars. The inset is the approximate binocular view of the comet at the time.	North-western sky on Tuesday, September 17 as seen from Adelaide at 19:35 ACST (90 minutes after sunset, click to embiggen). The track of the comet over successive nights is shown (ignore the magnitudes, the comet is around magnitude 7).

Comet C/2025 R2 (Swan) is (very) recently discovered comet that is around magnitude 7 (binoculars only), but it is well placed near some very bright guide stars so it will be easy to find (especially Mars and Spica this week). it is currently a dim dot in 10x50 binoculars. It will brighten a bit as it climbs higher into the darker skies, but will not really reach visual magnitude.

For this week it is relatively low above the horizon, and sets an hour after astronomical twilight, so you have a narrow window to observe. https://www.aerith.net/comet/catalog/2025R2/2025R2.html see also https://www.minorplanetcenter.net/mpec/K25/K25RA2.html for an ephemeris.


Black and White printable chart of the western sky starting Tuesday, September 17 as seen from Adelaide at 19:35 ACST (90 minutes after sunset, click to embiggen and print). The track of the comet over successive nights is shown (ignore the magnitudes, the comet is around magnitude 7).	Black and White printable chart suitable for binoculars of the comet for September 17 to September 23. (90 minutes after sunset, click to embiggen and print). Use in conjunction with the spotters chart.	Black and White printable chart suitable for binoculars of the comet for September 23 to September 30.(90 minutes after sunset, click to embiggen and print). Use in conjunction with the spotter chart.

Labels: binocular, C/2025 R2, comet

# posted by Ian Musgrave @ 5:47 pm 0 comments

The New Moon is Monday September 22. The Earth is at Equinox on the 22nd as well. Mars is passing through Virgo leaving the star Spica behind. Comet C/2025 R2 is near Spica (binoculars only). On the 24th the crescent moon forms a triangle with Mars and Spica. Saturn is at opposition, when it is biggest and brightest as seen from Earth on the 21st and is visible the entire night. Venus and Jupiter are visible in the morning twilight, Venus is close to the bright star Regulus and the crescent Moon on the 20th low in the twilight.

The New Moon is Monday September 22. The Earth is at equinox, when day and night are of equal length, on the 22nd as well.

Eastern twilight sky on the morning of Saturday, September 20 as seen from Adelaide at 05:43 ACST (30 minutes before sunrise, click to embiggen).

Venus is hard to see deep in the twilight glow. It is very close to the bright star Regulus (zoom into the image to see it), you may need binoculars to see Regulus. The thin crescent moon is close by.

Similar views will be seen from the rest of Australia at roughly the equivalent local time (30 minutes before sunrise).

North-eastern twilight sky on the morning of Saturday, September 20 as seen from Adelaide at 05:14 ACST (60 minutes before sunrise, click to embiggen).

Jupiter is passing through Gemini and is near the bright star Pollux. Jupiter forms a triangle with the bright stars Procyon and Betelgeuse. Venus is just rising.

The inset is the telescopic view Jupiter at this time.

Similar views will be seen from the rest of Australia at roughly the equivalent local time (60 minutes before sunrise).

Eastern sky on the evening of Saturday, September 20 as seen from Adelaide at 19:35 ACST (90 minutes after sunset, click to embiggen).

Saturn is at opposition, when it is biggest and brightest as seen from Earth. Saturn is visible all night long. The inset shows the telescopic view at this time .

Similar views will be seen from the rest of Australia at roughly the equivalent local time (90 minutes after sunset).

North-western sky on Saturday, September 20 as seen from Adelaide at 19:35 ACST (90 minutes after sunset, click to embiggen). Comet C/2025 R2 (Swan) is just above Mars. The inset is the approximate binocular view of the comet at the time.

Comet C/2025 R2 (Swan) is a (very) recently discovered comet that is around magnitude 7 (binoculars only), but it is well placed near some very bright guide stars so it will be easy to find. It will brighten a bit as it climbs higher into the dark skies, but will not really reach visual magnitude.

For this week it is relatively low above the horizon, and sets an hour after astronomical twilight, so you have a narrow window to observe. More information and printable charts here. https://astroblogger.blogspot.com/2025/09/how-to-see-new-comet-c2025-r2-swan-from.html

Similar views will be seen from the rest of Australia at roughly the equivalent local time (90 minutes after sunset).

North-western sky on Wednesday, September 24 as seen from Adelaide at 19:08 ACST (60 minutes after sunset, click to embiggen). Mars is drawing away from the bright star Spica. The crescent Moon form a triangle with Mars and Spica.

Similar views will be seen from the rest of Australia at roughly the equivalent local time (60 minutes after sunset).

Whole sky on Saturday, September 20 as seen from Adelaide at 19:36 ACST, 90 minutes after sunset (click to embiggen).

Mars is in the north-west. Saturn is in the east

Bright Achernar is rising from the Southern horizon. Scorpius is setting in the west and the galactic core is coming off the Zenith.

The Southern Cross is sinking in the Southern sky. The moon is new and the fainter clusters and nebula are easier to see.

Elsewhere in Australia will see a similar view at the equivalent time (90 minutes after sunset).

Mercury is lost in the morning twilight.

Venus Venus is hard to see deep in the twilight glow. It is very close to the bright star Regulus, you may need binoculars to see Regulus. The thin crescent moon is close by on the 21st.

Mars is passing through Virgo leaving the star Spica behind. On the 24th the crescent moon forms a triangle with Mars and Spica.

Jupiter climbs in the morning twilight above Venus. Jupiter forms a triangle with Procyon and Betelgeuse.

Saturn is at opposition, when it is biggest and brightest as seen from Earth on the 21st. Saturn is visible all night long.

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 @ 6:00 pm 0 comments

The Last Quarter Moon is Sunday September 14. Mars is passing through Virgo and is close to the bright star Spica on the 13th. The contrast between blue-white Spica and orange Mars will be nice. Saturn is rising in the early evening and is the brightest object above the eastern horizon. Jupiter is readily visible in the morning twilight. The crescent Moon, Jupiter and the bright star Pollux form a triangle on the 17th. Venus is becoming harder to see deep in the morning twilight.

The Last Quarter Moon is Sunday September 14.

North-eastern twilight sky on the morning of Thursday, September 17 as seen from Adelaide at 05:18 ACST (60 minutes before sunrise, click to embiggen).

Jupiter forms a triangle with the crescent Moon and the star Pollux. Venus is becoming harder to see low above the horizon

The inset is the telescopic view of Jupiter at this time.

Similar views will be seen from the rest of Australia at roughly the equivalent local time (60 minutes before sunrise).

Eastern sky on the evening of Saturday, September 13 as seen from Adelaide at 19:29 ACST (90 minutes after sunset, click to embiggen).

Saturn is rising higher above the eastern horizon. The insets shows the telescopic view at this time .

Similar views will be seen from the rest of Australia at roughly the equivalent local time (90 minutes after sunset).

North-western sky on Saturday, September 13 as seen from Adelaide at 19:29 ACST (90 minutes after sunset, click to embiggen). Mars is at its closest to the bright star Spica.

Similar views will be seen from the rest of Australia at roughly the equivalent local time (90 minutes after sunset).

Whole sky on Saturday, September 13 as seen from Adelaide at 19:29 ACST, 90 minutes after sunset (click to embiggen).

Mars is in the north-west near bright Spica.

Bright Achernar is rising from the Southern horizon. Scorpius is westering and the galactic core is at the Zenith.

The Southern Cross is sinking in the Southern sky. The moon is waning and the fainter clusters and nebula are becoming easier to see.

Elsewhere in Australia will see a similar view at the equivalent time (90 minutes after sunset).

Mercury is lost in the morning twilight.

Venus is lowering in the morning twilight moving away from Jupiter.

Mars is lowering in the evening sky and passing through Virgo towards Spica. Mars is close to the bright star Spica on the 13th. The contrast between blue-white Spica and orange Mars will be nice.

Jupiter climbs in the morning twilight above Venus. Jupiter forms a triangle with the crescent Moon and the star Pollux.

Saturn is rising when the sky is fully dark, but is best in the late evening.

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 @ 11:14 pm 0 comments

The Full Moon is Monday September 8. There is a Total Lunar Eclipse on the morning of the 8th. Mars is passing through Virgo heading towards the star Spica. Saturn is rising in the early evening and is the brightest object above the eastern horizon. On the 8th the Full Moon is close to Saturn. Venus and Jupiter are visible in the morning twilight and are drawing apart. Jupiter is close to the star Wasat in Gemini on the 7th

The Full Moon is Monday September 8. There is a Total Lunar Eclipse on the morning of the 8th. The Moon is at perigee, when it is closest to Earth, on the 10th.

North-eastern twilight sky on the morning of Sunday, September 7 as seen from Adelaide at 05:32 ACST (60 minutes before sunrise, click to embiggen).

Jupiter is spectacularly close to the star Wasat (𝛅 Geminorum, not visible in this image as Jupiter is too close to it). Jupiter forms a triangle with Procyon and Betelgeuse. Venus is becoming harder to see low above the horizon

The insets are the telescopic views of Venus and Jupiter at this time. and the binocular view of Jupiter and Wasat.

Similar views will be seen from the rest of Australia at roughly the equivalent local time (60 minutes before sunrise).

Eastern sky on the evening of Saturday, September 6 as seen from Adelaide at 22:00 ACST (click to embiggen).

Saturn is rising higher above the eastern horizon. The insets shows the telescopic view at this time .

Similar views will be seen from the rest of Australia at roughly the equivalent local time.

North-western sky on Saturday, September 6 as seen from Adelaide at 19:24 ACST (90 minutes after sunset, click to embiggen). Mars is heading towards the bright star Spica.

Similar views will be seen from the rest of Australia at roughly the equivalent local time (90 minutes after sunset).

Western horizon as seen from Adelaide on 8 September at 3:42 ACST. The Moon is at totality. The inset shows the telescopic/binocular view at this time. Click to embiggen.

Further details and exact timing for several Australian cities are at this link.
https://astroblogger.blogspot.com/2025/08/total-lunar-eclipse-september-8-2025.html

Similar views will be seen from the rest of Australia at roughly the equivalent local time.

Whole sky on Saturday, September 6 as seen from Adelaide at 19:24 ACST, 90 minutes after sunset (click to embiggen).

Mars is in the north-west.

Bright Achernar is rising from the Southern horizon. Scorpius is westering and the galactic core is at the Zenith.

The Southern Cross is sinking in the Southern sky. The moon is waxing and the fainter clusters and nebula are becoming harder to see.

Elsewhere in Australia will see a similar view at the equivalent time (90 minutes after sunset).

Mercury is lost in the morning twilight.

Venus is lowering in the morning twilight moving away from Jupiter.

Mars is lowering in the evening sky and passing through Virgo towards Spica.

Jupiter climbs in the morning twilight above Venus. Jupiter forms a triangle with Procyon and Betelgeuse.

Saturn is rising when the sky is fully dark, but is best in the late evening.

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 @ 6:43 pm 0 comments