Observe the sky: January 2025

This month of January not only do we continue this internet corner to stay up to date on the various astronomical events we can enjoy this month, but we also have two new sections dedicated to the phenomena starring Jupiter’s satellites and the passages of the International Space Station (ISS) visible from Granada. We are aware that January can be a complicated and stressful month for our students, but we hope that in some way you can use these articles and the Universe that surrounds us to disconnect. To start, here are the main astronomical events we can enjoy during January.

Day	Time	Event
3	13:02	Earth at perihelion ( 0.983 AU)
3	17:22	Moon in conjunction with Venus, 1.30° S of Venus
4	17:57	Moon in conjunction with Saturn, 0.61° N of Saturn
7	00:58	First Quarter
8	02:25	Moon at perigee ( 370318 km)
10	04:43	Venus greatest eastern elongation ( 47.16°)
10	23:03	Moon in conjunction with Jupiter, 5.36° N of Jupiter
13	23:30	Full Moon
14	04:51	Moon in conjunction with Mars, 0.21° N of Mars
16	03:39	Mars at opposition
19	02:26	Venus in conjunction with Saturn, 2.19° N of Saturn
21	05:54	Moon at apogee ( 404277 km)
21	21:33	Last Quarter
28	22:48	Moon in conjunction with Mercury, 2.45° S of Mercury
29	13:38	New Moon

Table 1: Main astronomical events of the month of January. Local time.

During January we leave behind the Sun’s minimum altitude above the horizon (which occurred last December 21st) and we will begin to notice how the days start getting longer. For its part, the Moon will start the year with an illumination of approximately 3% coming from its new moon phase with which we said goodbye to 2024.

Sun during January 2025. — **Figure 1:** Variation of the Sun's position during the month of January. Left: Maximum daily elevation of the Sun during the month. Right: Position in the sky if observed every day at the same time (12.00 UT). In orange the positions of the Sun throughout January; in yellow, throughout the year (analemma).

Moon during January 2025. — **Figure 2:** Observability and illumination of the Moon during the month of January 2025. In red the time zone (universal time, UT; local time = UT + 1) during which you will be able to observe the Moon. The vertical white lines indicate the time of the Moon's passage through the local meridian.

Moon during January 2025 (II). — **Figure 3:** Phases and Moon orbit during January 2025.

If what interests us is planetary observation, January, like December, is a good month. In the early days of the month we will have Venus, commonly known as the evening star, as the brightest object after sunset (effectively, it is that super bright “star” towards the Southwest). On the other hand, Mars and Jupiter will be in good conditions for observation throughout the night. Saturn, which each time shows us rings more on edge, will be observable during the first half of the night in the constellation of Aquarius. Neptune and Uranus will also be observable, but as always, we will need telescope assistance for these, although it is always comforting to follow their movement with respect to the background of fixed stars. The following block of images summarizes this information visually.

Planets observability towards the beginning of January 2025 — **Figure 4:** Observability of the different planets of the Solar System from Granada in January 2025. In red, the time zone (universal time) during which you will be able to observe the different planets. The vertical white lines indicate the time of the passage of the various planets through the local meridian.

Planets observability towards the middle of January 2025 — **Figure 4:** Observability of the different planets of the Solar System from Granada in January 2025. In red, the time zone (universal time) during which you will be able to observe the different planets. The vertical white lines indicate the time of the passage of the various planets through the local meridian.

Planetary situation for the month of January 2025 in Granada. — **Figure 5:** Representation of the sky that will be observable at the end, beginning and middle of a typical January night from Granada (January 15th is chosen as representative). The positions of the planets as well as their motion relative to the fixed stellar background are indicated. For the planets with less apparent motion (Jupiter, Saturn, Uranus and Neptune) a zoom is included for tracking with telescopes.

As we anticipated at the beginning of the article, this month we add a new extra, a table summarizing the main phenomena starring Jupiter’s satellites. Jupiter, around which orbit more than 90 moons, has 4 satellites known since Galileo’s time, the Galilean satellites: Ganymede, Europa, Callisto and Io. These, not only are observable with binoculars and small telescopes, but also star in projections of shadows on the surface of the gas giant (solar eclipses), occultations and transits. Additionally, the Great Red Spot, one of the main storms in the Jovian atmosphere can be visible if we know where and when to look. In this table (Jupyter table) you can find all the phenomena observable from Granada as well as some extra information. Especially interesting will be the night of January 9th to 10th, a night when we can enjoy the projection of Io’s shadow, the occultation of Ganymede, Io’s transit, and Ganymede’s eclipse.

From the stellar point of view, the January sky perfectly exemplifies the beautiful winter sky. The January sky will be dominated by the constellation of Orion, the blueness of Sirius, Castor and Pollux hand in hand in the constellation of Gemini, or the majesty of the Pleiades among many other interesting asterisms.

The sky over Granada during the month of January 2025. — **Figure 6:** Representation of the sky that will be observable on a typical January night from Granada. The ecliptic is indicated (dashed line) as well as the main deep sky objects.

Finally, the second addition for this first month of 2025 is a table with dates, times and characteristics of the moments when the International Space Station will be visible from Granada (ISS table).. Probably without realizing it, on more than one occasion you have already observed this artificial satellite with the naked eye. And it is the brightest artificial satellite. With this table there will be no room for doubt, but you can also do your own campaigns to track down the ISS. You can’t miss the days of January 4th and 30th, when the ISS will be observable with a magnitude of -3.3 and -3.9 respectively.

And so we welcome this year 2025. Let’s hope this is the year we strengthen this initiative and that the weather finally allows us to carry out our observations. Please remember that we are open to suggestions on our Telegram channel, where you can also stay up to date with activities, workshops, talks… Here is the enlace! We hope to see you soon at our activities.

Clear skies and happy new year! And above all, good luck with your exams!