The next few days are ideal for planetary observations. In particular, the Jupiter opposition just recently occurred and it is now that the last period of Mercury’s visibility this year continues. That’s why we invite you on a fascinating journey through the starry sky, where you will learn when and how you can see all the planets during the night, from sunset to sunrise!
Rare clear winter nights are characterized by frostiness: clouds do not cover us with a dense cozy blanket, so the ground quickly cools down. Fortunately, to see all the planets, you will not have to be on duty all night, it will be more convenient to split the observations into two series: evening and morning, and in the morning you will have only Mercury to catch.
Venus
We will start our virtual tour with the brightest planet in the Solar System, Venus, which is now slowly moving away from the Sun against the background of the stars and will be in its greatest eastern elongation on January 10. This beauty is easy to see as soon as our daytime luminary is hidden: it will be about 21° above the horizon and will appear earlier in the sky than the stars, in a direction between south and southwest. You can even organize a little game with friends or relatives, competing to see the “Evening Star” first.
Especially experienced observers can try to find Venus even before sunset. Moreover, it is quite realistic to see it even in the daytime sky, when the Sun is still high above the horizon. To do this, we advise you to use a virtual planetarium (there are a lot of such applications for phones nowadays), estimate approximately where the planet is in the sky, hide from the Sun behind a building, and try to focus your vision on infinity.
If you have a telescope, you will also see Venus better in a bright sky than in a dark sky. The fact is that this planet has the highest albedo – it reflects 76% of light, which is why we see it so bright. By comparison, for the Earth, this indicator is about 30%. Excessive “sparkle” will prevent you from seeing the phase of Venus in a telescope in a dark sky. And observing it in a still-light sky, you can easily see that it looks like a tiny Moon in about the first quarter phase. Be careful during daytime observations, because even a small ray of sunlight focused by a telescope can permanently damage your vision.
Photo: Tom Williams
Saturn
The sky is getting darker, and we continue our journey. We move a little eastward to Saturn, which is located in the constellation Aquarius. It will be at its highest altitude (31°) exactly to the south these days at about 5:00 p.m. In the telescope, you can still see its magnificent “outfit”. But the planet is slowly moving away from us, and in March, when the rings will be maximally closed, will disappear in the sunlight. If now we see them from the northern direction, next year they will appear from the south.
Don’t forget to pay attention to the satellites too! Amateur telescopes are usually capable of showing up to 5 “Lord of the Rings” satellites. But even with small instruments, you can see at least the largest of them, Titan. If you have a medium or large telescope, you have a chance to see Titan’s shadow slowly creeping over Saturn’s disk from 7:30 p.m. on December 22. Be patient: the tiny black dot will become visible during the most stable atmospheric moments.
Photo: Lucca Schwingel Viola
Neptune
The most distant planet in the solar system, Neptune, is also accessible to the lucky owners of telescopes and binoculars. It is currently located 13° east of Saturn, on the edge of the constellation of Pisces. It is the only planet that cannot be seen with the naked eye, as its luminosity reaches only +7.9 star magnitude, meaning it is almost 6 times fainter than those that can be seen in a quality dark sky.
Because of its small angular size, Neptune is difficult to distinguish from the stars. Here again, we suggest using a virtual planetarium and comparing the star pattern it shows with what you see through the telescope. When you are sure that you are looking in the right area, you can increase the magnification (change the eyepiece to a short-focus eyepiece) and see the planet’s barely blue disk.
Uranus
Well, we are moving on to the constellation of Taurus. Here, not far from the Pleiades star cluster, is where Uranus now resides. Uranus is only slightly larger in physical size than Neptune, but it is much closer to us, making it easier to distinguish from the stars. It is the most distant planet in the solar system that, in theory, can be seen with the naked eye. But in reality, with a brilliance of +5.6m, it requires a dark sky and keen eyesight. So in this case, too, it is best to equip yourself with binoculars or a telescope.
Even at relatively low magnifications through average amateur telescopes (110-200 mm in diameter), the planet can be seen as a tiny pale blue disk. The satellites of Uranus become accessible for visual observations only for larger instruments.
Jupiter
Taurus is a real diamond in the rough: Jupiter, the largest planet in the solar system, shines brightly all night long. Even without telescopes, it will be an aesthetic delight, as it will remain the most visible object in the sky after Venus sets, surrounded by bright constellations such as Gemini, Auriga, Perseus, and Orion. Even a small telescope will allow you to see the dark bands on the planet’s disk, as well as the 4 largest satellites: Io, Europa, Ganymede, and Callisto.
If you schedule your observations for December 23, you will get a nice bonus: at 11:42 p.m., the tiny shadow of Jupiter’s satellite Europa will start moving across Jupiter’s disk. By the way, as with Venus, Jupiter reveals itself quite differently in a bright sky. Without too much contrast, in a medium telescope, you will be able to see many light and dark swirls in the bands, particularly (if you are lucky) the Great Red Spot, as well as countless thin veins in the circumpolar latitudes.
Mars
The last “stop” in the evening observations will be the planet Mars, which is now in the small constellation of Cancer. At about 9:00-9:30 p.m., Mars will rise high enough above the eastern horizon.
Observing conditions for the Red Planet are improving now, as it will be in opposition in mid-January. This makes the planet, which appears as an orange “star”, very bright, with a luminosity of -0.9m. If you’re lucky with atmospheric stability, you’ll be able to see the brighter icy polar cap through the telescope.
Mercury
The morning observing session includes only one planet, Mercury. But on December 26-27 at the same time, you may be pleased by the Moon’s thin crescent. You should start hunting for the “elusive planet” at about 7:00 a.m. The exact time depends on your geographic location.
We recommend observing about 50-60 minutes before sunrise. But keep in mind that Mercury will still be quite low above the horizon – somewhere around 7-8 degrees. Therefore, you should be especially careful when choosing an observation site – you will need an open southeastern horizon. Because of atmospheric absorption, the planet will have a reddish coloring, roughly like Mars. And with a telescope, you will be able to see its phase, which will be about 50%.
Photo: Raimondo Sedrani
Have a good sky and productive observations!
