January is always a great treat for astronomers. It’s going to be a spectacular start to 2025! The three most brilliant planets are all on view in the evening sky, with Mars at it’s nearest for two years. Add to that the Moon moving in front of Saturn and then in front of the Seven sisters star cluster. We will also have a spectacular display of shooting stars in the hours before dawn of the 3rd January from the Quadrantids meteor shower.
The New Year also opens with a chorus line of brilliant stars, led by Betelgeuse, and Rigel, in the constellation of Orion. Nearby is Aldebaran, the bright red eye of Taurus. Capella adorning Auriga. Castor and Pollux, the celestial twins in Gemini, and glorious Sirius in the constellation Canis Major. The long January nights are illuminated in the evening by brilliant Jupiter and by dazzling Venus before dawn.
If you are out to watch some fireworks on New Years Eve, why not also look up and see if you can spot some of these classic winter star patterns. If you look south you should be able to spot the ‘winter triangle’ or the ‘winter hexagon’.
The winter triangle is made up of Betelgeuse (in Orion), Sirius (in Canis Major), and Procyon (also in Canis Minor), making a neat and almost perfect equilateral triangle. All three are bright stars, meaning this is easy to spot even in a light polluted area.
If you want to extend your geometry theme further, you could also find the six stars from six different constellations that make up the winter hexagon. The stars in the asterism are Sirius and Procyon, along with Rigel (in Orion), Aldebaran (Taurus), Capella (Auriga) and Pollux (Gemini).
Amongst these stars Rigel, as a blue supergiant, and Aldebaran, as a red giant, will be differentiated by their colours. Let your eyes adjust to the darkness, have a careful look and see if you can appreciate the bluish colour of Rigel to the red or orange of Aldebaran.
The Earth will reach perihelion (its closest point to the Sun in its orbit) on the 4th January. On this date we will be 147 million kilometres away from the Sun. It won’t make a difference to the weather, but maybe the thought of our star close at hand will keep you warm whilst stargazing during the could January nights.
The planets:-
MERCURY
Mercury will be in the morning sky this month, very low in the south east. The innermost planet shines at magnitude -0.4 and rises above the horizon about 6.40am.
VENUS
Just before dawn breaks, Venus is resplendent in the south east, with a magnitude of –4.0. The morning star rises around 5.30am. The crescent Moon lies to the right of Venus on the nights of the 8th and 9th of this month
MARS
Despite being only the third brightest planet on view, Mars is still more resplendent than any of the stars; shinning at magnitude –1.5. On 12th of this month the red planet is nearer to the Earth than it has been since 2022, and is directly in line with the Sun and the Earth a few days later, on the 16th. The full Moon slims past Mars in the early hours of the 14th. Visible all night long, the red planet moves from Cancer to Gemini mid month. Mars can be found in line with the twin stars of Gemini; Castor and Pollux.
JUPITER
Second only to Venus in brightness, Jupiter can be found in the constellation of Taurus near the star Aldebaran. At magnitude –2.6, the gas giant falls below the horizon around 5am. On the 10th of this month the almost full Moon will be very close to Jupiter.
SATURN
The ring world starts the month in the constellation of Aquarius just to the upper left of Venus. At magnitude +1.1, it is 200 times fainter than the evening star. The Moon occults Saturn on 4th of the month. As Venus moves upwards, it passes to the right of Saturn, on 18th January. At the end of this month Saturn sets at 8pm.
URANUS
You may see it with the naked eye, but binoculars will be an advantage to locate this gas giant. Look in the constellation of Aries; it will be shinning at magnitude +5.7, and will set around 3.30am.
NEPTUNE
Faint Neptune. Which does well to have a magnitude of +7.8, is located in the constellation of Pisces in the south east. You will need good binoculars or a telescope to track it down. It falls below the horizon about 10pm.
PLUTO
This distant planet will be below the horizon during the hours of darkness this month.
CERES
The largest body in the asteroid belt is dim with a magnitude of +9.16. It falls below the horizon around 5.15pm and is located in the constellation of Capricornus.
Special Events:-
3rd January – There will be a pairing up of bright Venus and the crescent Moon as night falls.
4th January – The crescent Moon moves in front of Saturn. The occultation starts between 5.13 and 5.23pm (the exact time depending on your location) when the dark edge of the Moon hides Saturn. The ring world emerges from the Moon’s bright side between 6.20 and 6.31pm.
10th January – Between 1.30 and 4am the Moon slices across the lower part of the Pleiades star cluster, hiding four of the bright seven sisters: Merope, Alcyone, Atlas and Pleione, and many of its fainter stars.
13th and 14th January – The full Moon passes only 12 arcminutes from Mars, with the stars Castor and Pollux nearby.
21st January – The last quarter Moon is near to the star Spica.
25th January – The crescent Moon is near the red star Antares.
Meteor Showers:-
The Quadrantids meteor shower extends from the 28th December to 12th January, but it peaks on the morning of the 3rd January. It can be a fantastic firework display of its own, with showers sometimes peaking at 110 meteors per hour. We should have good views of these bright colourful shooting stars, as the Moon will be out of the way.
They are also unusual for a number of reasons. Meteor showers are usually named after the area of the sky they appear to originate from. The Quadrantids are named after Quadrans Muralis, which is a constellation that no longer exists. It was first named in 1795, but omitted from the ‘official’ list of constellations that was set by the International Astronomical Union in the 1920’s. This shower is not only interesting in being named after a now non-existent constellation, but the origin of the shower is also unusual. Most meteor showers are caused by comet debris, but it’s been suggested that this shower comes from asteroid 2003EH1.
Phases of the moon for January are :-
First quarter 6th January
Full Moon 13th January
Last quarter 21st January
New Moon 29th January