The Sky over the Mornington Peninsula — December 1991
Highlights this month
- 9MonMercury in inferior conjunction with the Sun — lost in the glare. (1:52am)
- 10TueThe Moon passes Saturn — 3° apart. (7:27pm)
- 14SatGeminids meteor shower peaks (up to 150/hr). A 48% Moon washes out fainter meteors for part of the night.
- 18WedMercury is stationary — resumes direct (eastward) motion. (10:31pm)
- 22SunSummer solstice.
- 22SunUrsids meteor shower peaks (up to 10/hr). A bright 99% Moon interferes badly this year.
- 28SatMercury at greatest morning elongation (22° from the Sun, mag −0.3) — best morning apparition. (7:20am)
- 31TueJupiter is stationary — begins retrograde (westward) motion. (10:04pm)
Sun & twilight
| Date | Sunrise | Sunset | Day length | Astro. dark begins | ends |
|---|---|---|---|---|---|
| Sat 1 | 5:51am | 8:27pm | 14h 36m | 10:19pm | 3:59am |
| Mon 10 | 5:50am | 8:35pm | 14h 45m | 10:30pm | 3:55am |
| Thu 20 | 5:52am | 8:42pm | 14h 50m | 10:39pm | 3:55am |
| Mon 31 | 5:59am | 8:46pm | 14h 48m | 10:42pm | 4:03am |
Days lengthen by about 11 minutes over the month.
The Moon
- New MoonFri 6, 2:58pm
- First QuarterSat 14, 8:39pm
- Full MoonSat 21, 9:28pm
- Last QuarterSat 28, 12:49pm
Apogee 10 Dec (405,800 km) · Perigee 22 Dec (358,400 km)
The planets
Rise/set for mid-month at The Briars.
| Planet | In | Mag | Rise | Transit | Set | Best |
|---|---|---|---|---|---|---|
| Mercury | Oph | 1.3 | 5:13am | 12:18pm | 7:22pm | Hidden |
| Venus | Lib | −4.0 | 3:38am | 10:21am | 5:05pm | Hidden |
| Mars | Oph | 1.5 | 5:08am | 12:26pm | 7:46pm | Hidden |
| Jupiter | Leo | −1.9 | 1:12am | 6:51am | 12:30pm | Morning |
| Saturn | Cap | 0.6 | 9:05am | 4:13pm | 11:21pm | Evening |
| Uranus | Sgr | 5.9 | 7:21am | 2:42pm | 10:03pm | Hidden |
| Neptune | Sgr | 8.0 | 7:38am | 2:54pm | 10:10pm | Hidden |
Meteor showers
- Geminids — peaks 14 December, radiant in Gemini (up to 150/hr). The richest shower of the year; the radiant reaches a useful altitude after local midnight, so it rewards southern observers well. A 48% Moon washes out fainter meteors for part of the night.
- Ursids — peaks 22 December, radiant in Ursa Minor (up to 10/hr). A circumpolar northern shower whose radiant never rises from Victoria. A bright 99% Moon interferes badly this year.
The solar system — December 1991
Evening sky Morning sky Up much of the night Lost in the Sun’s glare
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Generated automatically from the MPAS sky engine on 18 August 2026.