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After alluding to these events last time, we are today going to take a look at the upcoming partial lunar and annular solar eclipse. The Partial lunar eclipse will occur in September, but we will look all the way forward into early October to catch the solar eclipse as well.

All lunar eclipses happen during Full Moons, as this is the only time that the Moon can end up directly behind the Earth. We’ve already discussed the Full Moon occurring in September, so we will skip straight to the appropriate night of the 17th. This will let us see the Moon as technically a Supermoon and at 99.9% full. By moving past midnight into the 18th we will see the moon come up to 100% full. This partial lunar eclipse is going to be very much a partial, only a very small portion of the Moon is going to pass into Earths umbra, the darker part of the shadow. The penumbra is the outer shadow surrounding the umbra. This will almost totally cover the Moon, but it is much more subtle and difficult to spot. The greatest extent of the umbra will occur at about 2:45 in the morning, but ten or fifteen minutes either side should still allow you to see some true darkness on the edge of the Moon. The penumbra will cross onto the just after midnight, and won’t fully move off until nearly 5 am. However, unless the umbra of he Earth is visible on the Moon, you may not notice the difference. This is only a partial eclipse, meaning that the Moon is crossing the ecliptic almost directly in line with the Earth and the Sun.

This partial lunar eclipse is happening during a Supermoon, and thanks to the Moon being a little closer to us and appearing a little bigger, the shadow on the Moon may be a little easier to notice. In the attached video, to help improve the chances of noticing the penumbra, I removed the atmosphere. This causes the Moon to appear to drop a little in the Sky. Our atmosphere bends or refracts light passing through it, making things appear in slightly the wrong position, just like looking at things through water. The Moon appears a little bit higher in the sky than it actually is thanks to this effect. Without the atmosphere in the way, it’s certainly a little easier to see the dimming effect of the penumbra. Even with no atmosphere in the way, the dimming of the penumbra is hard to spot, while the truly dark umbra stands out clearly. Only a small portion of Moon will be in shadow, about 3.5%, making it difficult to see with the naked eye. You absolutely have to pay attention to catch it, and using a telescope or binoculars will make it easier. A Full Supermoon not only appears a little bigger in the sky, but also a little brighter. For this reason I would recommend using an aperture at the front of your telescope, or something else to reduce the amount of light that’s coming through. These are often called reducers, filters can also be used to make the light of the Moon a little bit less intense and these usually go on the back-end or eyepiece of the telescope. If you’re looking at the Moon through a telescope, when it’s completely full, on a perfectly clear night, especially when it’s a Supermoon, it can be uncomfortably bright. We are looking at sunlight, even if it is reflected off the Moon, so it’s a good idea to be careful just in case.

Staying at the location of Ireland, if we really could remove the atmosphere, we might be able to see the upcoming New Moon, in the sky with the Sun during the day. If we replaced the Earth with something transparent, We would be able to see the New Moon happening on the other side of the planet. In the same way that the 100% Full Moon is only visible from certain parts of the Earth each month, the absolute New Moon is also only visible from certain locations. Moving forward to the 2nd of October, we can see the 100% (or 0%) New Moon, but only by looking through the hypothetical transparent Earth, as It will occur over North and South America. From Ireland, we will be of course not able to actually see it. If we could, we would see the New Moon hanging below the Sun. Even looking through the Earth, we do not get to see the annular solar eclipse, we’re just to high on the planet. If this eclipse was visible at our latitude, but visible when it’s night time for us and daytime from somewhere else, then looking through the Earth we’ would be able to see it. The reason we’re not seeing it is because it’s not visible in our hemisphere, unlike the lunar eclipse which will be visible in both hemispheres.

The partial lunar eclipse will be visible over a good chunk of the Earth, a large region of space, it’s going to be visible in Africa, Europe and most of the Americas. The annular solar eclipse on the other hand, will only be visible across a narrow path, moving from the Pacific Ocean across the Southern portion of South America. The path of annularity, which is similar to the path of totality for a total solar eclipse, will cross the continent of South America a little higher than the very tip. In Argentina, it will move through the province of Santa Cruz rather than Tierra del Fuego. In Chile, the path goes between the Northern and Southern Ice Fields, as well as passing over Easter Island. Technically the eclipse is going to be visible along a big swathe of the Pacific as well, but unfortunately the path of annularity manages to miss most islands, Various islands in the Pacific will see various degrees of a partial annular solar eclipse, with Kingsman Reef and Palmyra Atoll getting the closest to the center of the path. However, this is an annular solar eclipse, so even though the Moon is going to be in front of the Sun, it will not completely block it out even at it’s maximum.

An annular Solar eclipse is the New Moon equivalent to a micromoon, the opposite of the supermoon. As the Moon is at its closest to us when it’s behind us this lunar cycle, then when it’s in front of us for it will be at its furthest from us. Thanks to the slow precession of the Moons elliptical orbit, what phase the Moon is in when it’s is closer to us and when it is further away from us varies over the year. Given that our Full Moon in September is a super Moon, and the Moon will be almost at it’s closest to us, the Moon must be almost at it’s furthest from us when it reaches the opposite side of it’s orbit in October. Thanks to objects appearing smaller when they are further away, Moon will be too apparently small to block out enough of the Sun for just the outer atmosphere to be visible. The bright photosphere, the main part of the Sun is still going to be visible all through the eclipse, and that’s going to be bright enough to block out the corona. It is the corona and the filaments of plasma it is made of, that give a total solar eclipse a fuzzy surrounding.

If you do catch the solar eclipse at maximum annularity, you will see that the Moon is completely in front of the Sun. The disc of the Moon will be completely inside the disc of the Sun, with a little bit of Sun visible the whole way around. Even if the Moon doesn’t appear to be at the dead center of the Sun, there is enough of an apparent size difference for sunlight to be visible the whole way around. The Moon is just too far from us to block out the Sun completely. Of course, if the Moon was closer to us then it would and we’d have a total solar eclipse. The size ration of the Moon and the Sun for this annular eclipse is 0.925 or 1:0.925, it’s not perfectly 1-to-1 as it would be in a total eclipse. The disc of the Moon is shown in the video as obscuring 85.72% of the Sun, so we’re still seeing a little bit more than 10% of the Sun around the outside. It seems like about 86-87% is the absolute maximum visible this time from any location. This does make the annular eclipse similar to seeing 86% of a total solar eclipse, but it is different. Although an annular solar eclipse may be less impressive than a total solar eclipse, seeing an annular eclipse at maximum annularity is still better than any partial eclipse. At the maximum point of the eclipse, the sky doesn’t get that much darker. It appears like this is going to be visible reasonably early in the day for people in the right location of South America, which may make any dimming harder to notice, as It won’t necessarily occur at midday.

I wouldn’t recommend pointing a telescope at any kind of solar eclipse, the heat generated can do a lot of damage to your telescope. The normal kind of viewing precautions that you’d use for a total solar eclipse also apply to an annular eclipse. Wear eclipse glasses or welders glass to protect your eyes while looking at the Sun. An even safer option is to use some sort of a projection system like a pinhole camera, which can be made out of a shoebox ,and watching the light getting projected out the other side or even projected onto a piece of paper. Indirect observation through projection is the safest, though correct eclipse glasses are good as well. I’d recommend looking at this eclipse and even though it’s annular and not total. It is still a really cool phenomenon, it’s interesting to see the “ring of fire”, the bright ring of sunshine around the Moon. An annular eclipse almost makes the Sun and the Moon look like a giant eye in the sky. Even if you’ve already seen a total solar eclipse, an annular eclipse is a nice one to add to your collection.

Of course if you’re not down in South America, if you’re up here in Europe like me, at least you’ll still get to see the partial lunar eclipse that’s coming up just at the end of September. I hope that you enjoyed this piece on the upcoming eclipses and how the distance between the Earth and Moon effect eclipses, especially solar ones. If you did enjoy it you can like this article, and if you’d like more like this then you can subscribe to this website and to my YouTube channel. Whatever else, I hope to see you back here again next time.