Caoimhín's Content

Today, we are going to take a look at the Moon. We are coming up to the Full Moon for the month of July, so we’re going to take a look at how the Moon is going to behave from here to the end of the month. As some of you may remember, I am hoping to do a question and answer piece, but I haven’t gotten too many questions, so I’m going to leave them build up. I think it’s better that I wait until I have a reasonable number of questions before I make any sort of question and answer piece, but for those of you who are waiting for that, it is still upcoming. Of course, feel free to ask more questions as I do need more of them.

We will begin by taking a look here at the Full Moon on 10 July, just after 11 o’clock when it’s risen here in Ireland. Catching the Moon just as it rises, you may see it having a nice kind of orangey, off-white color. That’s because we’re seeing it at sunset, with that orangey glow in the sky. As we push later in the night, it gets back to the pale grey and white colour that we’re used to seeing the Moon as. However, if you do catch the Moon, especially a Full Moon, rising just as the Sun is setting, it’s very likely to have this nice orangey-yellow color. This is often called a Harvest Moon, but it can happen at any time of the year, it’s not specifically related to any given harvest. The Harvest Moon is also the name for the Moon closest to the autumnal equinox in September, but under that scheme, this Moon is the Strawberry Moon. Despite not being red, it is close to the time for harvesting strawberries, which does almost make it a harvest Moon in other sense as well.

The Full Moon is going to be reaching its highest close to physical midnight. Here in Ireland, that’s just about 1:30 in the morning. The Moon however, won’t be at it’s very highest at that time for us. We’re after moving into the 11th of July now, past midnight, and the Moon is 99.8% full. We can move through the night to see if we hit 99.9% at any part of the night, but of course we may not hit that or 100%. In this case, we go down to 99.7% instead. We’re not seeing the Moon at 100% full, so we’re not seeing the Moon directly above the south in the exact middle of the night. We need to wait until nearly 2 o’clock before the Moon reaches due south. That’s definitely not a physical midnight or midnight on the clock. Due to daylight savings and the size of time zones, when physical midday and physical midnight happen do vary from the corresponding clock times. In this case, the Moon hasn’t reached due south at physical midnight, as it would if it were 100% full. For some part of the world, when the Moon really is 100% full, the Moon will be directly above the south for the local physical midnight. Unfortunately, it won’t be that for anywhere in Ireland, it’s not up at the right time, but it will be for some other part of the world. The Moon is of course moving around us reasonably quickly, it only takes just under a month for the Moon to get the whole way around the Earth. As such, we can’t be sure it’s in the right place at the right time without knowing its exact phase as well. The Sun coming to its position of physical midday is a lot more reliable for time telling.

As we follow the Moon from rising to its highest point, the Moon appears to rotate, coming close to what you may call upright, as it reaches its highest. We often see the Moon like that, with the north pole of the moon pointing north, in images and pictures. These are usually seeing the Moon at its highest when it’s at its fullest, often in winter when it’s even higher in the sky. When the Moon is rising and setting, it does look a little bit different, almost like it’s tilted to the side. Of course from different latitudes, the Moon would look different as well. If we were down in the southern hemisphere, then we’d see the Moon completely upside down, we’d see it inverted compared to what we’re used to. We won’t really see too much of a twist as we go from sunset to sunrise at the moment. The night is still very short and the Moon is very low in the sky, so we’re not seeing the Moon move across as much of the sky. This means we’re not seeing as much of that twisting, that side to side rotation, as we would do in the winter.

Taking a closer look at the Moon, I’ll point out a few things on the surface. This is particularly for anyone who is new enough to this website, as I haven’t said this in a while, so perhaps it bears saying again. A lot of people imagine a face when they look at the Moon, but I often imagine or point out a football player. The shape is composed of the dark regions on the right side of the Moon when you are looking at it full and high in the sky. The left side, your left, should be almost one big dark area in the upper-mid portion. Starting at the north on the right (your right) the first dark section is the head. Just below, like a snowman, is the body. Below the body are two smaller dark regions, the two legs, and just on the edge ahead of them is the football. The body of the football player is the Sea of Tranquility. Before laparoscopic surgeries, if you got your appendix out, the scar would be pretty close to being over the location of your appendix, which is usually on the right side of your torso. Taking the football player as a mirror image, as if this football player was facing you, and they had an appendix scar, around there is where the astronauts landed. It’s over on the lower left hand side, your left facing the Moon again, that is where the Eagle lander landed, that’s where the Apollo 11 moon landing occurred. It happened in the Sea of Tranquility, but specifically down around thar region, reasonably close to the edge of the sea as well.

Of course, all of the seas and oceans have names. The head of the football player is the Sea of Serenity, with the two legs being the Sea of Nectar and the Sea of Fecundity. The football is the Sea of Crises, and I sometimes say that the Sea of Vapors is the footballer’s hand, waving. Most of the left of the Moon is the Ocean of Storms, while the lobe just next to the footballer’s head is the Sea of Rain-Showers. None of these is filled with liquid water, but they were briefly filled with a liquid. Billions of years ago, when the interior of the Moon was still liquid magma, big craters were caused by large impacts during the era of Late Bombardment. They pierced the rocky crust of the Moon and left the liquid rock flow out. These dark regions are where the lava flowed. The paler parts of the Moon are paler because they haven’t been rejuvenated by fresh magma washing over them. Looking at the Half Moon, the lower part of the Moon here, the pale highland, is visibly covered in cracks and craters. We can see them thanks to the striking shadows that they cast during the Half Moon. When the shadow is lying across the darker areas, even with the craters highlighted by their shadows, we can see there are far fewer of them. That’s because the older craters from before the heavy bombardment, they’re still there in the uplands where we can see them as texture, but they’ve been wiped away in the dark seas, oceans and bays, the lowlands of the Moon. That’s one of the reasons why various Moon landings have landed in the darker areas, it’s smoother, easier to traverse terrain.

As we move through the phases, as we push through the month, the Moon passes pretty close to Saturn there as it comes up to half, or third quarter. Looking for as close to half as we can ge, it looks like 49.5%, which is pretty close to a half. As we saw with the Full Moon, we don’t get exactly 100%, we don’t get exactly 50% or exactly 0% either, not every month at least. We can see here moving into the morning, the Moon has joined the morning planets at the end of the month. This means it will be out of the way for stargazing in the evening. The Moon isn’t getting that close to Jupiter and Venus, but it is certainly in the same region of the sky. It’s also getting much much older. The age of the Moon is one way to talk about its phase. Its phase when it is between Jupiter and Venus is a waning crescent here, already very small. This is obviously a lot harder to see even if it was truly dark. Against the orangey-yellow glow of sunrise, it’s going to be even trickier to spot, but it is there with those planets as we move later in the month. Once we get through to the end of the month, the last few days of the month, the Moon is out of the sky entirely. This means we can be in with a slightly better chance of seeing things, meteors in particular. I mentioned in some of the previous piece the meteor shower that’s coming up at the end of the month. I will revisit it once we get to the end of the month, but having a sky without any Moon in it, even if we are in the city, will to help you see more things, the light of the Moon still has an effect.

The light of the Moon has even more of an effect if we’re out in the countryside. Later in the month, dark skies will have a nice clear view of the Milky Way. We are past the summer solstice, so even though by late July the sky is pretty much at absolute nighttime once we’re around physical midnight, there may still be a little bit of a glow in the north, especially if you’re closer to the northern parts of Ireland or if you’re anywhere further north on the globe. If you’re reasonably closer to the equator, closer than Ireland at least, then it should be no issue. If you’re in a dark sky, the Moon will be completely out of the way once we’re through to the end of the month. Moving into the morning, a little bit of the outer edge of the Milky Way swings over the Sun, but it’s disappearing pretty quickly as the Sun comes up. Earlier in the night we have a reasonable view of the Milky Way’s center. If you are in a perfectly dark sky, that can be seen coming up reasonably early in the evening, appearing just as it comes to due south. The galaxy is pretty much at its best, but not for a very long time. Parts of the core go back under the horizon almost as soon as they become visible.

If we move back to our night of the Full Moon, we can see that the Full Moon is very close to the core of the Milky Way. They’re not in exactly the same place, but they are very close together, and that’s because we’re seeing the glow of the Milky Way pretty much in the south and the Full Moon goes past the south. We see the Full Moon close to the south when it’s at its highest and when it’s at its fullest, when those things come together. As such, the Moon is definitely an issue for the early to mid part of the month, but once we get into the later part of the month it’s much less of an issue. The Moon may still be there and the light of the Moon will still have an effect, but the Half Moon reflects a lot less light than the Full Moon.

Stellarium, as well as giving the exact phase, gives the age of the Moon in days. Let’s say the Moon is Waning Gibbous. This is past Full but before Half, specifically Third Quarter. This phase lasts for a few days, and the age of the Moon in days increases as we move from Full, through Half and towards Waning Crescent, and then New. Once the Moon reaches 29 and a half days old, it passes in front of the Sun, and we start back at zero. It’s one way to talk about the phases of the Moon if you need more accuracy than Waning Gibbous or Waxing Crescent and so forth. A 1 day old Moon is when the Moon has just come out from in front of the Sun. We know we’re not seeing the fullest point, the fullest that we’re getting to see is around 14.9 days old. This isn’t quite exactly halfway through the 29 and a half day cycle, and of course that makes sense because we’re not seeing it exactly 100% full.

So that’s a bit about the Moon, one of the most prominent objects in the night sky, that’s specifically how it is going to look for this latter part of July as we move from the Full Moon to the increasingly less Full Moon for the rest of the month. I do hope you enjoyed this piece, if you did, please do like it. If you enjoy this kind of content, then please subscribe to this website and my YouTube channel so that you see more of it. Don’t forget to ask questions as well, if you have any questions, feel free to drop them in the comments below and hopefully I’ll answer them in the near future. Thank you very much for reading and I’ll see you back here next time.