The moon is Earth’s only natural satellite, orbiting our planet at an average distance of 384,399km – about 30 times Earth’s diameter. On September 8 there will be a total lunar eclipse, when the sun casts Earth’s shadow over the moon. Photo: MPAS member Liam Laube
Highlights this month
- 6SatUranus is stationary — begins retrograde (westward) motion. (1:04pm)
- 9TueThe Moon passes Saturn — 3° apart. (3:14am)
- 13SatMercury in superior conjunction with the Sun — lost in the glare. (8:39pm)
- 16TueThe Moon passes Jupiter — 4° apart. (10:44pm)
- 21SunSaturn at opposition — closest and brightest of the year, up all night in Pisces (mag 0.5). (3:11pm)
- 23TueSpring equinox.
- 23TueNeptune at opposition — closest and brightest of the year, up all night in Pisces (mag 7.8). (10:39pm)
- 24WedThe Moon passes Mars — 4° apart. (9:28pm)
Be sure to enjoy the rich regions of Scorpius and Ophiuchus this month before they sink below the western horizon. Just above them lies a rich region around the heart of the Milky Way, brimming with star clusters and bright nebulae. In contrast, the eastern half of the sky is relatively empty, although you can still find several constellations, including Pisces, the Fishes; Cetus, the Whale; and Eridanus, the River.
Lying in the constellation Tucana, the Small Magellanic Cloud can be found close to the beautiful globular cluster 47 Tucanae, also known as NGC 104, which is a must-see target in the September southern skies. It is visible to the naked eye as a hazy star, while a small telescope shows its bright centre and many of its glittering stars. This cluster is 15,000 light-years away. Other visible targets include the globular clusters M22 in Sagittarius, NGC 6397 in Ara, and M4 in Scorpius. The open clusters M6 and M7 in Scorpius are also visible.
There are also a few interesting targets in Aquarius. The globular cluster M2 appears as a fuzzy star through binoculars and is near the star Beta Aquarii. And the planetary nebula NGC 7293, the Helix Nebula, appears as a faint fuzzy disc through a small telescope. Another globular cluster, M15, in Pegasus, is thought to be 13.2 billion years old and can be picked out with binoculars, while a small telescope shows it clearly.
The Mornington Peninsula Astronomical Society will host its biannual Telescope Learning Day on September 20. Suitable for all ages and for absolute beginners on their astronomy journey – whether you own a telescope or not – the day involves talks during the afternoon and early evening, then telescope practice and use outdoors as it darkens. Booking are essential; see the website for more details.
By Nerida Langcake
This article appeared in the September 2025 issue of the Mornington Peninsula Magazine.
The sky in detail — September 2025
Sun & twilight
| Date | Sunrise | Sunset | Day length | Astro. dark begins | ends |
|---|---|---|---|---|---|
| Mon 1 | 6:42am | 5:58pm | 11h 16m | 7:26pm | 5:14am |
| Wed 10 | 6:28am | 6:06pm | 11h 37m | 7:34pm | 5:01am |
| Sat 20 | 6:13am | 6:14pm | 12h 02m | 7:43pm | 4:45am |
| Tue 30 | 5:57am | 6:23pm | 12h 26m | 7:53pm | 4:28am |
Days lengthen by about 70 minutes over the month.
The Moon
- Full MoonMon 8, 4:13am
- Last QuarterSun 14, 8:31pm
- New MoonMon 22, 5:57am
- First QuarterTue 30, 9:56am
Perigee 11 Sep (364,600 km) · Apogee 26 Sep (405,600 km)
The planets
Rise/set for mid-month at The Briars.
| Planet | In | Mag | Rise | Transit | Set | Best |
|---|---|---|---|---|---|---|
| Mercury | Leo | −1.6 | 6:32am | 12:23pm | 6:15pm | Hidden |
| Venus | Leo | −3.7 | 5:14am | 10:31am | 3:49pm | Hidden |
| Mars | Vir | 1.6 | 7:43am | 2:16pm | 8:50pm | Evening |
| Jupiter | Gem | −1.8 | 3:22am | 8:11am | 1:00pm | Morning |
| Saturn | Psc | 0.5 | 6:30pm | 12:45am | 6:55am | All night |
| Uranus | Tau | 5.7 | 11:43pm | 4:41am | 9:36am | Morning |
| Neptune | Psc | 7.8 | 6:42pm | 12:50am | 6:55am | All night |
Computed for The Briars, Mt Martha. Times are local (Melbourne).
Generated automatically from the MPAS sky engine on 15 July 2026.
The solar system — September 2025
Evening sky Morning sky Up much of the night Lost in the Sun’s glare
Open the full interactive orrery ↗ — fast-forward, pick any date, toggle the Moon and more.
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