JANUARY 2025

Mars in Opposition

This month Mars will be easily visible every night, weather permitting. With Earth on an inner faster track around the Sun making two orbits for Mars' one, a line-up of Sun, Earth and Mars occurs roughly every 24 months. This brings the Red Planet into Opposition - opposite the Sun from our point of view. At these times Mars is at its largest, brightest and closest to Earth. While Mars is smaller than Earth and further from the Sun, and receives less solar energy, it does share a similar day length and axial tilt which brings seasonal changes to its surface, polar caps, and thin carbon dioxide atmosphere.

Moon phases

Phase Date
First Quarter Tuesday 7th
Full Moon Tuesday 14th
Third Quarter Wednesday 22nd
New Moon Wednesday 29th

Moon distances

Lunar apogee (furthest from Earth) is on Tuesday 21st at 404,298 km.

Lunar perigee (closest to Earth) is on Wednesday 8th at 370,171 km.

Planets

Mercury is not seen this month as it is about to move behind the Sun.

Venus is bright in the west at dusk as the "Evening Star' from 9pm before setting by 11pm.

Earth will reach perihelion on January 3rd, its closest point to the Sun in the year at 147.1 million km. Six months later on July 4th, it will reach aphelion, its furthest point at 152.1 million km.

Mars is in opposition and can be seen from around 10pm in the north-east before fading in the dawn light by 5:20am in the north-west. It is easily seen this month, but binoculars or a modest telescope will reveal its dark and light areas and white polar caps.

Jupiter is visible from 9pm in the north-east and across the northern sky before fading from view by 3am.

Saturn is soon to pass behind the Sun, but is still faint but visible with its faint yellow colour from 9:30pm in the west at dusk before it sets around 11:30pm.

Meteors

While the Quadrantids in the Northern Hemisphere peak on the 4th in the Southern Hemisphere, the Eta Carinids are active from 14th-27th although fainter with only a few per hour that peak on the 21st. Their radiant, the point from which they appear to originate, is located near the star Eta Carina not far from Southern Cross.

International Space Station

ISS orbits every 90 minutes at an average distance of 400 km appearing like a bright star moving slowly across the night sky.  Heavens Above gives predictions for visible passes of space stations and major satellites, live sky views and 3D visualisations. Be sure to first enter your location under 'Configuration'. 

Stars and constellations

Our summer night sky includes two neighbouring galaxies, star clusters, red giant stars, easily recognizable constellations, and the band of the Milky Way with dense star fields and dark interstellar dust clouds.

In the South

The Southern Cross (Crux) and the nearby Pointers (Alpha and Beta Centauri) are easy to spot low to the horizon in early evening. Adjacent to the Southern Cross is the dark dust cloud known as the Coal Sack that forms a veil that blocks the light of more distant stars from reaching us. Enjoy this ESA page and ESA video.

High in the south on their own are our two neighbouring small galaxies the Large Magellanic Cloud (LMC) and Small Magellanic Cloud (SMC) at 160,000 and 200,000 light years respectively. From the southern hemisphere they are a treat and always visible in our skies which is not the case for equivalent latitudes in the northern hemisphere.

A recent interpretation is that the two Clouds of Magellan appear not to be orbiting our galaxy as long assumed, but in fact may be making their first pass of the Milky Way after colliding with each other around 300 million years ago. The collision may have distorted them, depleting them of gas and stars, leaving them diminished in their current irregular form.

In the East

The brightest star at night lies directly east - Sirius the principal star in the constellation of Canis Major (Greater Dog). It is 8.6 light years away and therefore a close neighbour to the sun but with twice the mass of our sun, greater size, surface temperature and luminosity.

In the North-East

The Saucepan asterism is easy to spot using the three bright stars as its base. They are the belt of Orion the hunter who is upside down in our southern perspective. Orion's scabbard or sword sheath (the saucepan's handle) contains a fuzzy object which is the beautiful Orion Nebula which is where new stars are developing from vast clouds of hydrogen and dust. Two very different stars are also part of Orion; top left is the hot blue giant Rigel as one of his feet, the other is the cooler red giant Betelguese at bottom right which is one of his shoulders.

In the North

An open cluster the Hyades some 150 light years away forms an inverted V which marks the head of Taurus the bull. At its lower right corner is Aldebaran another red giant which is much closer to us at 65 light years. To the left can be seen the more compact cluster of stars known as the Pleiades (or Seven Sisters). These hot blue stars are young, formed together and are only the brightest members of a much larger number of stars all bound together under their mutual gravity.

On this day

1st 1801, the first asteroid, Ceres, was discovered by Giuseppi Piazzi.

2nd 1959, first detection of solar wind by Luna 1 (USSR) as it passed the moon.

4th 1958, the first satellite, Sputnik (USSR), fell back into the atmosphere and disintegrated after 11 weeks in orbit.

4th 1959, first human-made object enters heliocentric orbit, Luna 1 (USSR).

4th 1643, birth of Isaac Newton famous for studies in optics, the reflecting telescope, laws of gravitation and motion, and co-creator of calculus.

5th 2005, discovery of the most massive and second largest dwarf planet, Eris at 2,300 km diameter, by team led by Mike Brown at Palomar Observatory.

8th 1942, birth of Stephen Hawking, theoretical physicist, cosmologist and science celebrity.

11th 1787, discovery of Uranus's first two moons, Titania and Oberon by William Herschel.

7th 1610, Galileo Galilei's discovery of Jupiter's four largest moons: Io, Europa, Callisto and Ganymede.

16th 1969, first docking in space and first crew exchange in space between Soyuz 4 and Soyuz 5 (USSR) in Earth orbit.

18th 1916, meteorite falls onto occupied house in Baxter, Missouri (USA).

19th 2006, New Horizons spacecraft (USA) launched to Pluto for its 2015 fly-by.

23rd 2003, final communication with Pioneer 10 (USA), first interplanetary probe to Jupiter, which later left the solar system.

25th 2006, first icy-rocky planet discovered orbiting a main sequence star, a red dwarf at 21,500 light years from Earth.

27th 1967, fire in Apollo 1 (USA) command module kills crew of three in ground test at Kennedy Space Centre.

28th 1986, space shuttle Challenger (USA), the 10th shuttle flight, explodes 73 seconds after lift-off killing all seven crew and halting the program for 32 months.

31st 1961, first hominid in space, chimpanzee Ham, in Mercury-Redstone 2 (USA), who survived and lived in zoos until 1983.

31st 1958, discovery by James Van Allen of radiation belts of charged particles from the Sun that surround Earth and which now bear his name.

31st 1958, Explorer 1 the first successful American satellite launch, and first satellite to carry instruments into space.