Caoimhín's Content

Today we are going to be looking at yet another conjunction. This conjunction is a little bit different from the conjunctions that we’ve taken a look at recently. Among those conjunctions was a conjunction of Saturn and Venus. That was at its best at around the seventh, so just past as of the date of posting. Looking back, Saturn and Venus were nice and close together in the sky at sunset. Today it is another conjunction of Saturn that we will be looking at.

In our previous piece where we looked at various planetary conjunctions, we looked forward into the end of March to see a conjunction between Mercury and Mars. Of course, that one wasn’t visible from Ireland, we had to head pretty close to the equator to see it. Coming up on the 15th at sunrise, Mercury and Mars are very close together. If we keep moving forward, we’ll see Saturn coming around into morning time as well. Saturn, over the course of the end of March and into the beginning of April, is going to be moving from one side of the Sun to the other. This is a kind of conjunction. This is a superior conjunction which would seemingly indicate that it is better, but of course, superior conjunctions are almost always worse than any other kind. A superior conjunction is when a planet is directly in line with the Sun on the opposite side of the Sun to the Earth, putting it out of our view. So of course, this is the only kind of conjunction with the Sun that the planets outside of the Earth’s orbit can have.

Looking at the midday sky with no atmosphere, Saturn is in line with the Sun, Saturn is on the opposite side of the Sun from our perspective. Thanks to the slow motion of Saturn, it will be roughly on the wrong side of the Sun for a couple of days. However, Saturn looks pretty far from the Sun, it is visible quite far underneath the Sun, to the south. This would suggest that close to sunset down in the southern hemisphere, you might get to see Saturn over the Sun as it sets. This is something that we got to do with one of Venus’s superior conjunctions relatively recently. Checking both the Sun rising in the east and setting in the west, unfortunately because Saturn is pretty much directly behind the Sun, the angle prevents us from seeing Saturn. That was from quite far in the southern hemisphere, there might better chance if we’re a little bit closer to the equator, so we’ll try that. The superior conjunction is almost always a pretty boring conjunction because we don’t get to see the planets that are in that position. This time seems typical, Saturn looks to be to close to the other side of the Sun to be visible at all. Moving to a bit before its superior conjunction, Saturn would have been visible under ideal conditions, for example if we had a perfectly flat horizon. Stellarium can generate such a view, and move it into the countryside to minimize the amount of light pollution. This would maximize our chances of seeing Saturn because, but there is a lot of light just as the Sun is setting, keeping Saturn out of view even in these ideal conditions.

Superior conjunctions almost always block the planet in question from view, and that’s pretty much what we’re seeing here. Despite this, under certain conditions, such as recently with Venus, you can see the planet at sunset or sunrise. This is because even though the planet is more or less in line with the Sun, it is on the opposite side of the Sun from our perspective, it’s often not directly in line. These conjunctions are often not a perfect alignment of three objects, similar to how the New Moon will pass in front of the Sun, but not necessarily in line with the Sun. This is also something we could see while looking at the daytime sky with no atmosphere, which of course lets us take a look at the Sun, the Moon and the planets all together, all at the same time. Moving along to the New Moon, the is facing us with its nighttime side. The Moon is between us and the Sun, but it’s not directly in line, because of course if it was directly in line, we’d be getting a solar eclipse. Very similarly with the planets, even though the planets will pass behind the Sun, relatively speaking, they’re not always going to directly line up. We saw this recently enough as well with the inner planets. In the fairly recent past, we had Venus and Mars making a close conjunction around their superior conjunctions. Mars has to be on the far side of the Sun because Mars is further from the Sun than we are. Based on how bright Venus is, one can tell that Venus is on the far side of the Sun as well.

The innermost planets, like Venus and Mercury, can come between the Sun and the Earth. Usually planets on the far side of the Sun will be quite bright because they’re fully illuminated, they’re essentially in their full phase. Moving along until Mercury gets into that position gives us a New Mercury. Just like the New Moon, it’s darker, it’s much harder to see because its nighttime side is facing us. With Mercury between us and the Sun, this is an inferior conjunction, which only happens with the inner planets, planets that are closer to the Sun than we are. Inner planets like Mercury and Venus, they can have both superior and inferior conjunctions, the planets outside the Earth’s orbit, including Mars, but also Saturn and Jupiter, they can only have superior conjunctions. Again, superior sounds like it will be better, but in these instances we don’t actually get to see them. It’s much better to see them for us at opposition when, when they’re directly behind us on the same side of the Sun.

If we go through enough time, we’ll move forward into the year, we’ll see several of these conjunctions. Not long after Mercury’s inferior conjunction is its superior conjunction, and in this case it actually lines up with the Sun. Mercury’s next superior conjunction seems to have it actually going directly behind the Sun, which does of course happen as well. Occasionally planets will be directly in line with Sun. Uranus is directly behind the Sun in superior conjunction in the near future as well. It has to be a superior conjunction, there’s no other option for Uranus. Continuing forward, Jupiter passes directly behind the Sun. It is a superior conjunction, and a much closer one than Saturn’s, but still not directly in line with the Sun.

Similarly to the Moon, not always passing directly in front of the Sun and only occasionally causing a solar eclipse, we see the same with the planets and their conjunctions, whether they’re superior or inferior conjunctions. The next few inferior conjunctions of Mercury it’s not going to quite line up directly with the Sun. If it was, we’d get a transit of Mercury and of course, transits of Mercury and transits of Venus are fairly rare. We only get them every now and again, and that’s because, generally, the planets aren’t going to perfectly line up with the Sun. All of the orbits of the planets are at least slightly inclined away from the ecliptic. A lot of the time the ecliptic is defined based on the how the Earth orbits the Sun how that relates to the orbits of the other planets, but even the Earth is a little bit inclined from the equator of the Sun itself, if the equator of the Sun was projected out into space. By going through basically an entire year, we can check that the vast majority of these conjunctions, superior and inferior, they’re not perfect alignments. They’re not occultations of the planet by the Sun, even though I don’t think we’d normally use the term occultation to describe something going behind the Sun, but an actual zyzygy, a perfect alignment of three objects, that’s not always the case. In fact, that’s usually not the case with these kinds of conjunctions, it’s only occasionally, as we know with Mercury a little bit later this year, only occasionally will these alignments be perfect, will the object actually be blocked out by the Sun.

This is a conjunction that we can’t see, the superior conjunction of Saturn. Most superior conjunctions we can’t see, but at least you now know what it might be like. I hope that you enjoyed this piece, if you did then please do like it. If you like this kind of content, then please subscribe to this website and my YouTube channel. Thank you very much for watching and hopefully I’ll see you back here next time.