Your guide to the night sky this month
Saturday 1
Mag. +1.5 Mars lies 5.5˚ northeast of mag. +1.0 Antares (Alpha (α) Scorpii), both objects rising 100 minutes before the Sun above the southeast horizon. A delicate 2%-lit waning crescent Moon sits 8˚ east-southeast of Mars.
Sunday 2
Lunar perigee, the point where the Moon is closest to Earth, occurred at 23:00 UT on 1 January, making today’s Moon a perigee new Moon, also known as a supermoon. It doesn’t get as much coverage as a perigee full Moon since you can’t see it.
Monday 3
This evening into tomorrow morning is the best opportunity to watch the peak of the Quadrantid meteor shower. With new Moon on 2 January, this year’s peak is particularly favourable.
Tuesday 4
Mag. –0.6 Mercury, +0.9 Saturn and a 5%-lit waxing crescent Moon form a compact triangle low in the southwest after sunset. The trio are followed by mag. –2.0 Jupiter.
Earth is at perihelion, the closest point in its orbit to the Sun.
Wednesday 5
Catch this evening’s waxing crescent Moon as it sits 7.5˚ southwest 12%-lit of mag. –2.0 Jupiter.
Thursday 6
This evening, the now 20%-lit waxing crescent Moon sits 9.3° east-southeast of Jupiter.
Friday 7
Mercury reaches greatest eastern elongation today, appearing separated from the Sun by 19.2° in the evening sky. The mag. –0.5 planet sets approximately 100 minutes after the Sun.
Saturday 8
Orion reaches its highest position in the sky, due south around 22:40 UT, just after the waxing crescent Moon sets. This a great time to get a last look at the Sword region before the Moon starts to interfere.
Monday 10
January’s ‘Moonwatch’, the crater Nasireddin, can be seen near the terminator this evening.
Comet C/2019 L3 Atlas reaches perihelion today and appears at its brightest, around mag. +9.7.
Wednesday 12
An evening view of the Moon through binoculars reveals an arc of light extending into darkness. The arc represents the Jura mountain peaks illuminated by the lunar dawn, a clair-obscur effect known as the ‘Jewelled Handle’.
Thursday 13
Minor planet 7 Iris reaches opposition today. Shining at mag. +7.7, Iris can be located roughly midway between Pollux (Beta (β) Geminorum) and Procyon (Alpha (α) Canis Minoris).
Friday 14
Mag. +0.6 Mercury and mag. +0.9 Saturn appear 3.6˚ apart in the early evening sky. The pair should be visible 30 minutes after sunset. They remain above the horizon for around 90 minutes after sunset.
Saturday 22
Look at the southwest limb of this morning’s 83%-lit waning gibbous Moon and you may be able to make out the dark lava patches of Mare Orientale and the lunar lakes that surround it.
Wednesday 26
This morning’s 42%-lit waning crescent Moon occults the double star Zubenelgenubi (Alpha-1 (α 1 ) Librae and Alpha-2 (α ) Librae) around 05:23 UT (time correct for the centre of the UK).
Thursday 27
As Sirius (Alpha (α) Canis Majoris) passes its highest position, due south around 22:30 UT, look 4° south of the star using binoculars to locate the beautiful open cluster M41.
Friday 28
On this morning’s 21%-lit waning crescent Moon, the bright crater Aristarchus is near the terminator about two-thirds of the way up. Aristarchus (40km) is the brightest feature on the Moon’s Earth-facing side.
Saturday 29
Mag. +1.4 Mars lies 5.4° to the northeast of this morning’s 12%-lit waning crescent Moon. Catch them together with mag. –4.5 Venus 10.5° to the northeast of Mars, 80 minutes before sunrise low above the southeast horizon.
Family stargazing
Orion is prominent, making this an excellent time to introduce the Hunter to young observers. Point out the three Belt stars in the middle of the main pattern. Identify the faint line of the Sword, hanging below the Belt. At the bottom of the main pattern are Saiph (left) and Rigel (right). Compare the colour of Rigel with orange Betelgeuse in the upper-left corner. Betelgeuse is old and running out of fuel; it is believed to be a thousand times larger than our Sun. In the upper-right corner is Bellatrix and in between and higher, is a triangle representing Orion’s head. bbc.co.uk/cbeebies/shows/stargazing
NEED TO KNOW
The terms and symbols used in The Sky Guide
Universal Time (UT) and British Summer Time (BST)
Universal Time (UT) is the standard time used by astronomers around the world. British Summer Time (BST) is one hour ahead of UT
RA (Right ascension) and dec. (declination)
These coordinates are the night sky’s equivalent of longitude and latitude, describing where an object is on the celestial ‘globe’
Naked eye
Allow 20 minutes for your eyes to become dark-adapted
Photo opp
Use a CCD, planetary camera or standard DSLR
Binoculars
10×50 recommended
Small/ medium scope
Reflector/SCT under 6 inches, refractor under 4 inches
Large scope
Reflector/SCT over 6 inches, refractor over 4 inches
GETTING STARTED IN ASTRONOMY
If you’re new to astronomy, you’ll find two essential reads on our website. Visit http://bit.ly/10_easylessons for our 10-step guide to getting started and http://bit.ly/buy_scope for advice on choosing a scope