Caoimhín's Content

Today we are going to talk more about the parade of planets that is coming up this month as well as the passage of the Moon across our sky. The parade of planets, all of the planets being on display, has become more and more of a big deal as we come into January. More and more papers and publications are talking about the four planets in the sky and calling it the parade of planets, the alignment, the conjunction, lots of words getting thrown around fairly indiscriminately.

First off, there are four planets in the sky over the course of January, there is no denying that, and they’re going to look great. I have talked about how Venus is going to reach its greatest elongation, how Mercury will come up when we get into February making it 5 planets visible, Mars passing its opposition, and these are all great things. However, saying that we have a conjunction or even an alignment, that doesn’t quite feel right.

We will look a little ahead, to the 12th of January, not to far in the future. The Moon will be up but it isn’t full, and all of the planets are above the horizon as early as sunset. The planet Saturn is definitely visible from the city here as early as 6 o’clock. In my videos, I very often show the sky with a big wide field-of-view, about 136 degrees. For a field of view, this is pretty big, nobody actually sees the sky like this, without some assistance. No humans at least, maybe some herbivores, such as rabbits and other prey creatures with very big fields of view. Generally, your field of view is going to be quite a bit smaller. Our view of the sky as normal humans doesn’t have a area that’s in focus, our periphery can see more, but it isn’t usually the focus. Many of us would look around the sky and see The Plough or the Big Dipper as a huge region of the sky. To the naked eye, even though it looks quite small if you’re looking at using the wide field of view provided by software like Stellarium, or the assistance of some sort of fish-eye lens.

This does mean that for this particular parade of planets, you will be hard pressed to see all four of them at the same time. We can definitely see Venus, Saturn and Jupiter together, and we can see Jupiter, Mars and the Moon, but seeing Mars and Venus at the same time is going to be tricky. You may be able to catch both of those planet in your periphery if you don’t quite focus on a point between them. Instead, sort of defocus, allow your eyes to spot what they can at the edges. Of course, using Mars’s reddish orange colour to spot it using your periphery may not work as your peripheral vision lacks any colour sensitive cells. Your brain just kind of fills in the gaps with colours that it would expect, and I’m sure that your brain would expect a dot in the sky to be a whitish colour rather than the orangey colour of Mars. Regardless, they are all going to be in the sky even if they are all tricky to see at the same time, however this isn’t a conjunction or an alignment. If we take a look at Saturn and Venus, they will be in a pretty close conjunction certainly a conjunction. They’re pretty much in a straight line, nearly, If you drew a line through Venus and extended it backwards into space you would hit Saturn, they’re just not directly aligned from where we are here on Earth. That would be an occultation, and we wouldn’t be able to see Saturn if it were directly in line with Venus and the Earth. If we were a little bit higher in the solar system, above the plane of the Ecliptic, sort of looking down on Venus, it would be able to block out Saturn, if we lined things up right. Technically, if you were able to freely move around space, you would be able to put almost any pair of planets in line with each other if you were willing to move around to great distances and go above or below the ecliptic.

Speaking of above or below the ecliptic, I mentioned the occultation of Saturn that the Moon created at the beginning of the month. Moving ahead in the month form this point, into what is still the future at the time of posting, I mentioned that we wouldn’t get an occultation of Jupiter because it was too low under the ecliptic or the Moon was too high above the ecliptic. Either one can deviate form the ecliptic, so it could have been either or both. I didn’t check at the time, but having now checked, Jupiter is a little bit under the ecliptic, while the Moon is a good bit above. Stellarium can display the ecliptic in two different ways. The first is the J2000 epoch ecliptic. The J2000 epoch is the reference time of midday on January 1st 2000. It is a lot more specific and detailed than that, but in short it serves as a reference time for measurements. The J2000 epoch is the one that is currently used, but we are in a slightly different part of the epoch, so I use the ecliptic of date which makes some small adjustment, though it doesn’t matter much. By comparing the line of the ecliptic to the actual positions of the planets, Jupiter is a little under it though not by much, Mars is significantly above it, Saturn is a little under and Venus is pretty much on the ecliptic, a little under. These planets over the course of their orbits they will, go above and below the ecliptic. This is especially easy to see with Venus. Thanks to the short orbit and the angle at which we see it, it goes across the ecliptic fairly regularly. It will be above the ecliptic at the end of the month and it has been under the ecliptic closer for the start of the month. Indeed, it’s still a little under the ecliptic around today’s date. Pushing ahead to the 16th and Venus is exactly on the ecliptic from our perspective.

It’s the only one. Venus the only one of the planets that’s actually on the ecliptic. If the line deviated just a little, it would cross through Jupiter. You could absolutely create a line that passes through any pair of the planets, but there is no straight line that passes through all four of these planets. As such, they are not in a line, they are not aligned. This is not really an alignment. The conjunction between Venus and Saturn is almost an alignment, but all four planets together are not. That’s fine of course, but alignments sound cool. Conjunctions sound cool as well, and we do have a conjunction of two planets with Venus and Saturn.

The parade of planets will look a bit more spread out than many of the images currently associated with the parade of planets. A lot of the things that people are using to show off the parade of planets artists interpretations at best. At worst they are artificially generated images that don’t have any conscious constructive thought behind them, just an assortment of features composed into a visual image based on recorded patterns. Even an artists interpretation is always going to try and make things look better, more visually impressive, which is of course the point. If it was just a realistic depiction it wouldn’t be an interpretation, it would just be a copy. A realistic drawing of the night sky that showed this collection of planets as they really are would be amazing to me, but I just don’t think it exists. I certainly don’t think I’ve seen a single one of them out there. I’m hoping that my attached video will give a slightly more realistic view of what this is actually going to look like in the sky and how much of it you could see. Even with the very wide field afforded by Stellarium, we’re barely seeing them all at the same time.

The planets of course will be visible from the city, but everything looks better in the countryside. I try to draw attention to the difference a dark sky makes in every piece, but of course for the planets it doesn’t make the hugest difference. I bring it up partly to remind you what you’re missing out on, and partly to show you why you should be writing letters to your local council telling them to fix the issue of light pollution, something which we should all be doing, myself included. You can of course head out to the countryside or visit one of the many dark sky parks around the world, including the pair in Ireland. From the countryside it’s even more worth while waiting little bit later so that it’s darker. All of the visible planets will be visible just after sunset, but the faint glow of the Milky Way won’t be visible until later, which of course isn’t a factor in the city. Even when true darkness falls, Venus and Saturn will still be comfortably above the horizon, with Jupiter and Mars quite high. The brightest star Sirius can be compared to Venus, and Uranus is of course out there as well, though it will usually require a telescope to observe.

While all these planets are up, it’s worth mentioning the constellations behind them. As the planets in our solar system move across the ecliptic, and the zodiacal constellations are those constellations on the ecliptic, if you see a planet in the sky, you’ve found one of the zodiacal constellations. It might be Ophiuchus, the 13th zodiacal constellations, but that’s something I’ve covered previously. Both Venus and Saturn are at the boundary of Aquarius, though we’ll see Venus moving into Pisces over the next few days. Venus was even deeper in Aquarius closer to the beginning of the month, but as we get to the end of the month it will push into Pisces, thanks to the speed of it’s orbit and retrograde motion. We can see Jupiter in Taurus and that’s not going to change for a while, nor will Saturn’s position in Aquarius. For the planets that are beyond the Earth’s orbit, they’re going to pretty much follow the motion of the stars across the sky. It could take months for Jupiter to move out of a constellation, but for planets that are closer to the Sun than we are, their movement is a lot more noticeable. Mars is going to be in Gemini, but moving back towards the beginning of the month it was in Cancer. We can see Mars’s motion there, as it does orbit reasonably quickly, but also due to the Earth catching up and over taking it. From the 16th of January all the way through to at least March, Mars is in Gemini. IN March, Mars will begin looping back around thanks to the retrograde motion around it’s opposition of Mars, but comfortably into March, Mars is there in Gemini. It was in Cancer closer to the beginning of January and still is for this weekend.

For most of the Parade of Planets, Mars is Gemini, Taurus has Jupiter and Aquarius has Saturn, with Venus moving into Pisces from Aquarius. Uranus is pretty much in Taurus, it’s almost in Aries, right on the edge between the two. The other constellations in the sky don’t have a planet in them at all, for now. Mercury will be moving up into Aquarius Next to Saturn when it becomes visible in February. It won’t be in Capricornus, because Capricornus will end up behind the Sun, though it may be in Capricornus while it is invisible.

I hope you get to see these planets and I hope you don’t feel too misled by any of the images you’ve seen online. It will be very difficult to see all four of the planets of the same time, however, rest assured that if you find one of these planets you found at least one of the zodiacal constellations. Then you can find some of the others using that as a starting point. I hope that you enjoyed this piece and I hope that you will subscribe to this website and my YouTube channel to support future pieces like this. Hopefully, I’ll see you back here next time.