Caoimhín's Content

In the previous video we took a look forward to the very early part of June, particularly the planets that we will get to see in the morning. Despite Mercury and Jupiter being too close to the Sun for us to see in Ireland, from other locations four planets would be visible in the sky together around June 4th. Later in June, Jupiter will come into view, so we only need to wait a few weeks to have three planets visible in the sky together. As we continue to push into June, we will reach the summer solstice. Although the actual moment when the Sun reaches it’s highest point at noon will occur on the 20th, it will occur at around 9 o’clock in the evening for us here in Ireland,. Just like conjunctions and eclipses, the exact moment of the solstices isn’t necessarily visible from every part of the world. For this reason, I’ll be sticking to the 21st of June as midsummer. The dates either side won’t be too different. By looking at the sky from Ireland at noon on the 21st, we can see that the Sun is certainly high in the sky, and we can take this to be its highest. Despite the high Sun and long day, midsummer isn’t usually the hottest point of the year. The Earth takes a while to heat up, with water being a little slower to change temperature than rocks and solid ground. This means that the Earth has to heat up from its coldest during the summer, and reaches it’s peak heat a little after the longest day of the year. The Earth then retains some heat as winter begins, only cooling to its coldest a little after the shortest day in midwinter. This phenomenon is known as the Lag of Seasons, as the actual earthly temperature seems to lag behind the physical middle of summer or winter. Hopefully it will be warm on the 21st of June, but we won’t reach our actual peak here in Ireland until as late as August. Closer to the equator and further inland this phenomenon is less pronounced, and the hottest day may occur only a few days after the solstice, where as it can lag behind by months closer to the poles and at coasts.

Moving into the night of the solstice, the length of the day is evident by how late we can see the glow of sunset. As late as 12 o’clock the sunset glow is clearly visible. 12 o’clock is technically midnight, but it isn’t out local, physical midnight. Thanks to daylight savings and Irelands position almost on the edge of our time zone, 12 midnight is no more our physical midnight than 12 noon being our physical midday. Daylight savings time pushes both of these by an hour, closer to 1 o’clock, and our position delays it by about another half an hour. We can see this during the day by using a sundial, or any object where you can measure it’s shadow at its shortest. If the Moon is full then it should reach directly above the South at physical midnight, but even without the Moon, just waiting an extra hour and a half after the clocks say midnight will correct the difference here in Ireland. For other locations, this will differ. If you live close to the center of your time zone in an area that does not use daylight savings, then midnight really will be 12 o’clock as expected. Even at our actual midnight, you may be able to notice just a little bit of a glow almost directly due North, if you are as far North as Ireland. We aren’t far North enough for the Sun to stay visible all night, but just a few hundred kilometers further North is the Land of the Midnight Sun. For certain northern Scandinavian regions and Iceland, the Sun will still up when it is midnight. We can’t see the Sun, but the light it’s producing does creep over the horizon, just like the glow of dusk or dawn appears before the actual sunrise. We normally think of daytime and night-time, without much concern for the twilight in between, but twilight can last for quite a while. If you are as far north as Ireland, in the summer there is a little bit of an orange glow in the sky all night long, which technically makes it not night at all, but twilight, from sunset until sunrise.

Moving forward to sunrise, by the solstice we will have three planets in the morning, Jupiter, Mars and Saturn. Mercury will be gone at this point, it will be back in too close to the Sun for us to see from most places on Earth. in the previous article and video, when I discussed the Parade of Planets, we saw that neither Mercury nor Jupiter were visible from Ireland, even though they were technically above the horizon. This Parade of Planets, with four visible planets above the horizon, and two invisible ones, will occur around June 4th. If you’re a bit closer to the equator, around the Mediterranean or Virginia in the United States will do. In Ireland we still get to see the Moon, Mars and Saturn early in the month and by the middle of the month it becomes possible to see Jupiter as well. Jupiter and Mars will be very low to the horizon, with Saturn being a little higher, visible even from inside a city with some light pollution.

Even in early June, Scorpius was beginning to become an evening constellation rather than a morning one, and by the solstice it will be above the South as early as midnight. As it happens, this year we have a Full Moon on the night of the solstice, making it much easier to see that our physical midnight is not the same as 12 o’clock. We will see the Moon very low above the South at about 1:30 in the morning, which does technically mean we have crossed over into the 22nd, but it is still the night beginning on the 21st. Things will look very similar at 1:30 in the morning of 21st, the night starting on the 20th. Again, it isn’t even technically night, just a very long twilight. Getting to see the Moon this low at it’s highest is really only possible if we have a Full Moon on the night of the summer solstice. Just as the Sun reaches it’s highest during the day, the path of the Moon reaches its lowest at night, but if the Moon is not full then it won’t be opposite the Sun. If the Moon is close to the Sun in the sky, then we will See it high in the sky, just like the Sun. We are lucky that the Full Moon is occurring around the solstice, as it is purely a coincidence, the solar and lunar cycles are not in sync, so the Moon could be any phase on the solstice for any given year.

When the Moon is low to the horizon, an optical illusion makes it look bigger, generally the Moon will look a little bit smaller when it’s higher in the sky. Catching the Full Moon as it rises is usually the best time to see this effect, and often the best time to photograph the Moon to try and capture the effect as well. The slightly illusory nature of the Moon’s apparent size is also part of the reason why it’s so easy to see the Moon with your eyes, but so difficult to photograph, especially with a mobile phone. Thanks to the low position of the Full Moon in midsummer, it will be close to the horizon all night long, making this a great time to try and observe or photograph it, if your Southern horizon is clear enough.

Unfortunately, this will contribute to obscuring the Milky Way as well. Even in a dark countryside sky, the Milky Way will be almost impossible to see. Of course, we don’t need to see the Milky Way to locate where it should be. Especially in the country side, we will see the teapot shape of Sagittarius and red star of Antares in Scorpius, where the core of the Milky Way sits. The arms of our galaxy will stretch up through the summer triangle, which is nice an high in the sky by midnight in midsummer. The Full Moon will be right next to Scorpius, in the perfect place to block out the core of the Milky Way. Even if we didn’t have the Moon in the sky, the Milky Way would be tricky to spot because we’re on the summer solstice. The sky isn’t really going to get fully dark at any point of the night, which would obscure the Milky Way to a degree. With the little bit of a glow in the sky and the light of the Full Moon, the Milky Way will practically invisible, with the glow of the Moon blocking out the brightest part, and the twilight glow creeping over the Northern horizon blocking out the fainter edges of the galaxy.

All of this makes midsummer, especially this year with the Full Moon, almost like stargazing on hard mode. You will have a very short amount of time to see things and there will be extra light in the sky blocking things out. Looking at the sunrise in the countryside, the Pleiades are just about visible just above Jupiter, they would be very hard to spot in the city due to the addition of light pollution on top of the orange yellow glow. Cassiopeia remains visible higher above the Sun, with the bright star Capella also visible just a little lower and roughly above the sunrise as well. We do have some nice things in the sky as the Sun rises, but the Sun is rising close to 4 o’clock in the morning, so you’ll have to get up even earlier to catch the sunrise, and stay up even later to catch watch the sunset. Despite the difficulty, the shortest night only comes once a year, and having the Full Moon this year makes it an even better.

I hope you do get to enjoy the long summer days even if they come with much shorter nights, and you can look forward to the actual heat coming a little bit later in the year once the Earth has warmed up. I may talk more about the solstice when we get a little closer to it and I will most likely talk about the June sky more generally as we get into the month. If you’d like to catch those upcoming posts, I recommend subscribing to this website and/or my YouTube channel, and hopefully that will bring you back here next time.