Mars is closest to Earth on 1 December, when it appears as a mag. –1.9 object among the stars of Taurus.

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On this date Mars has an apparent diameter of 17.2 arcseconds. At this size, albedo features – features that show different reflectivity – can be seen quite easily.

The most obvious are the dark, exposed rocky regions on the planet that contrast well with the surrounding lighter deserts.

In addition, the planet is sideways-on to us at present, potentially giving us a view of both polar regions.

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Chart showing Mars's path across the night sky in December 2022
Mars's journey across the night sky in December 2022 will see it close to the Pleiades and the Hyades on 31 December. Credit: Pete Lawrence

The southern polar cap will probably be absent, it being summer in Mars’s southern hemisphere.

The northern cap will be augmented by a large cloud shroud, known as a polar hood.

Mars reaches opposition on 8 December. Around this time the planet appears at its brightest and largest in terms of apparent size.

The difference in the apparent size of Mars when it’s at its most favourable opposition and when at its most distant from Earth. Credit: Pete Lawrence
The difference in the apparent size of Mars when it’s at its most favourable opposition and when at its most distant from Earth. Credit: Pete Lawrence

Observing Mars: tips and tricks

When observing Mars, it pays to be patient and allow your eyes to get used to the view.

It’s quite common to look at the planet and see nothing but a bright orange-pink disc through the eyepiece of a telescope.

However, as your eye becomes accustomed to the light, the subtle surface features become more obvious.

Albedo features on Mars. Credit: Pete Lawrence
Albedo features on Mars. Credit: Pete Lawrence

On opposition day, 8 December, Mars will be occulted by the full Moon – the lunar phase that sees the Moon also at opposition.

Mars disappears behind the lunar limb at 04:57 UT, reappearing back into view one hour later at 05:57 UT.

On 31 December, although it will have faded slightly to mag. –1.2, Mars will look quite resplendent against the stars of Taurus, near to the Pleiades and Hyades open clusters and 8° to the north of orange-hued Aldebaran (Alpha (α) Tauri).

Visible planets in December 2022

The phase and relative sizes of the planets in December 2022. Each planet is shown with south at the top, to show its orientation through a telescope. Credit: Pete Lawrence
The phase and relative sizes of the planets in December 2022. Each planet is shown with south at the top, to show its orientation through a telescope. Credit: Pete Lawrence

Mars

  • Best time to see: 1 December, 00:30 UT
  • Altitude: 62º
  • Location: Taurus
  • Direction: South
  • Features: Light deserts with darker exposed rock, polar caps, weather
  • Recommended equipment: 75mm or larger

Mercury

  • Best time to see: 29 December, 30 minutes after sunset
  • Altitude: 5º (low)
  • Location: Sagittarius
  • Direction: Southwest

A mag. –0.5 evening object, not well-positioned at the start of December when it sets with mag. –3.8 Venus, 30 minutes after the Sun. Greatest eastern elongation occurs on 21 December, Mercury appearing separated from the Sun by 20.1°.

On this date it lies 5.4° from mag. –3.8 Venus, setting 80 minutes after sunset. On 29 December, mag. +0.6 Mercury and –3.8 Venus appear 1.5° apart, low in the southwest after sunset. On this date, Mercury sets almost 90 minutes after the Sun.

Venus

  • Best time to see: 31 December, 30 minutes after sunset
  • Altitude: 5° (low)
  • Location: Sagittarius
  • Direction: Southwest

A bright mag. –3.8 evening object, slowly pulling away from the Sun. Telescopically, it is at its least optimal, 10 arcseconds across and over 90% illuminated. Venus chases Mercury, catching up with it late in the month. A 2%-lit Moon sits below both planets on 24 December, very low just after sunset.

Jupiter

  • Best time to see: 1 December, 19:32 UT
  • Altitude: 35°
  • Location: Pisces
  • Direction: South

A magnificent evening planet. Shining at mag. –2.5 on 1 December, it is joined by a 62%-lit waxing Moon 3.5° away before they both set in the early hours of 2 December.

A second lunar visit occurs on the evening of 29 December, this time from a 46%-lit Moon. It reaches its highest position in the sky, due south, under dark sky conditions for most of the month. On 31 December, it shines at mag. –2.2.

Saturn

  • Best time to see: 1 December, 17:15 UT
  • Altitude: 21°
  • Location: Pisces
  • Direction: South

A lovely 15%-lit waxing Moon sits 4.7° south of Saturn on the evening of 26 December. By the end of the month, mag. +0.9 Saturn sits 15° above the southwest horizon by the time darkness gets underway.

Uranus

  • Best time to see: 1 December, 22:20 UT
  • Altitude: 53°
  • Location: Aries
  • Direction: South

Mag. +5.7 Uranus is well-placed, due south at a dark-sky peak altitude over 50°. It is occulted by a 94%-lit waxing Moon on the afternoon of 5 December. It
disappears at 16:51 UT under darkening twilight and could be tricky. Reappearance should be easier, occurring under darker conditions at 17:17 UT. Find out more about this in our guide to the lunar occultation of Uranus.

Neptune

  • Best time to see: 1 December, 19:00 UT
  • Altitude: 33º
  • Location: Aquarius
  • Direction: South

Mag. +7.9 Neptune manages to attain an altitude around 30° under dark-sky conditions all month. A 36%-lit Moon sits 3.7° southwest on 28 December. Mag. –2.2 Jupiter remains close to Neptune too, 8° east at the end of the month.

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This article originally appeared in the December 2022 issue of BBC Sky at Night Magazine.

Authors

Pete Lawrence, astronomer and BBC The Sky at Night presenter.
Pete LawrenceAstronomer and presenter

Pete Lawrence is an experienced astronomer and astrophotographer, and a presenter on BBC's The Sky at Night.