Find out what planets are in the night sky tonight and throughout the month of December 2023.
Uranus is really well placed for viewing in December 2023, having reached opposition in the middle of November.
Uranus is able to attain a maximum altitude of 54° under truly dark skies as seen from the centre of the UK, maintaining this capability throughout December 2023.
It’s currently shining at mag. 5.6 and located less than 3° south of mag. 4.3 Botein (Delta (δ) Arietis).
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How to find Uranus in the night sky this month
Botein is a great navigational tool for finding Uranus, so that’s your starting point when locating the planet in December 2023.
Using average binoculars (7×50), locate and place Botein at the centre of the field of view.
This should position mag. 4.6 Epsilon (ε) Arietis near the edge of the field.
Look roughly one-third of the Botein-to-Epsilon distance from Botein in a southwest direction to locate mag. 6.2 54 Arietis.
Move a similar distance south of 54 Arietis to locate mag. 6.1 53 Arietis.
Being just half a degree fainter than Uranus, both stars are good candidates for confusion, but identified correctly they work well for locating the planet.
Uranus December 2023 key dates
At the start of December, Uranus is located east-southeast of 53 Arietis.
Moving slowly west-southwest, Uranus ends the month in line with 54 and 53 Arietis.
The appearance of this distant world doesn’t change dramatically over time.
On 1 December 2023 Uranus shines at mag. 5.6 and presents a 3.8-arcsecond disc, this degrading to mag. 5.7 with a 3.7-arcsecond disc by the end of the month – hardly any change.
A small telescope will show its greenish hue as well as the fact that it presents a disc.
Imaging under good seeing conditions may reveal subtle bands on the planet’s globe.
Extended exposures at high image scale may possibly reveal Uranus’s brighter moons.
Just be careful not to over-expose the planet too much, as that may hide them.
Guide to the planets, December 2023
Uranus
- Best time to see: 1 December, 22:40 UT
- Altitude: 54°
- Location: Aries
- Direction: South
- Features: Weak banding, colour, brighter moons
- Recommended equipment: 200mm or larger
Mercury
- Best time to see: 31 December, 1 hour before sunrise
- Altitude: 3° (very low)
- Location: Ophiuchus
- Direction: Southeast
Mercury reaches greatest eastern elongation on 4 December, separated from the Sun by around 21°. Shining at mag. –0.3 on this date, Mercury sets just over an hour after sunset. Despite an improving position, fading brightness towards the middle of the month means Mercury becomes harder to see.
Inferior conjunction occurs on 22 December, after which Mercury re-emerges into the morning sky rapidly. However, it’s dim as it does so, your best chance of spotting it being on 31 December when, shining at mag. +0.8, the planet rises 90 minutes before sunrise.
Venus
- Best time to see: 1 December, 05:55 UT
- Altitude: 16°
- Location: Virgo
- Direction: Southeast
Venus is a dominant morning object. On 1 December, shining at mag. –4.1, it rises fractionally over 4 hours before the Sun, giving 2 hours to appreciate it against astronomically dark skies. At the start of the month, mag. +1.0 Spica (Alpha (α) Virginis) lies 4.5° southwest of Venus.
At the start of December, Venus shows a 67%-lit, 17-arcsecond disc through the eyepiece, values which change to 77%-lit and 14 arcseconds across by 31 December. By the end of the month, Venus rises 3 hours and 10 minutes before the Sun. The Moon appears close on 9 December.
Mars
Mars is not visible in December 2023.
Jupiter
- Best time to see: 1 December, 21:50 UT
- Altitude: 50°
- Location: Aries
- Direction: South
Jupiter is a beautifully placed evening planet. Shining at mag. –2.7 at the start of December and –2.5 at the end of the month, it appears 50° up when due south as seen from the centre of the UK.
A bright gibbous Moon is nearby on the evenings of 21 and 22 December.
Saturn
- Best time to see: 1 December, 17:45 UT
- Altitude: 24°
- Location: Aquarius
- Direction: South
Saturn is reasonably well placed at the start of December, visible at its highest altitude, due south, under almost true dark-sky conditions. However, by New Year’s Eve Saturn’s peak altitude occurs when the Sun is still above the horizon.
Through the eyepiece, Saturn’s north pole appears tilted towards Earth by around 10°. A 28%-lit waxing crescent Moon sits 3.8° south-southwest of Saturn on the evening of 17 December, closest as the pair approach setting around 21:00 UT.
Neptune
- Best time to see: 1 December, 19:13 UT
- Altitude: 34°
- Location: Pisces
- Direction: South
Neptune is an evening planet, well-placed and at mag. +7.9 at the start of December, but deteriorating slightly towards the end of the month.
This article originally appeared in the December 2023 issue of BBC Sky at Night Magazine.