Lunar Eclipses Blue MoonsWhile I'm not a particularly avid lunar observer, it does make a very convenient target when you want to check whether the telescope is in good focus! And having got the thing in view you might as well take some pictures. I'm also not as interested in eclipses of the Moon as of the Sun (as they aren't anything like as dramatic) but if one comes along it seems silly to ignore it!
The best part of the Moon to photograph will always be the very edge of the sunlit part: this is called the terminator. In this area the shadows pick out the detail with the greatest definition. Away from the terminator even large craters get "washed out" and hard to see: compare the right and left halves of the pictures below (which are in "naked-eye" orientation i.e. how you would actually see it in the sky).
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| The dark oval area to the right is Mare Crisium, with craters Cleomedes, Burckhardt, Geminus & Messala running up from its top edge. To the left we have Mare Serenitatis (upper) & Mare Tranquilitatis (lower). | To the right is Mare Fecunditatis: the crater with the central peak is Langrenus. The other one with a central peak is Petavius, with Vendelinus in between. The large one the other side of Petavius is Furnerius. |
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A composite of five images running down the terminator of a "first quarter" Moon. There are too many craters visible to list any in particular, so I'll just mention that the arc of mountains circling the dark area to the top left are (from the top) the lunar Alps, Caucasus & Apennines. There are two Apollo landing sites visible in this image, Apollo11 about one-third of the way down the right-hand edge and Apollo15 in the far-north part of the Apennines: check out the close-up views below and see if you can find them! |
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An eclipse of the Moon happens when the Moon enters the shadow cast by the Earth, in the same way that an eclipse of the Sun happens when the Earth enters the shadow of the Moon. Lunar eclipses can be total or partial, depending on whether the Moon falls completely within the Earth's shadow or not, and because the Earth's shadow during a lunar eclipse is wider than that of the Moon during a solar eclipse (the Earth being larger than the Moon) they tend to last longer than solar events: totality can last up to 1hr 48mins. The last one this long was in 2000, but there's not another until past 3000AD!
As with my gallery of solar eclipses, I've tried to use the pictures I've taken to illustrate more than just the photogenic aspects, so this is a bit of a tutorial as well as a picture show! Take your pick from the following events:-
The images here are from a partial eclipse on 7th September 2006. It was in progress at Moon-rise, there were (naturally!) clouds about and I should have been at a rehearsal anyway, so I couldn't get a full sequence. I thus used it as a trial run for the total eclipse in 2007: good job too, as there were "exposure issues", let us say! I used the digital camera (as the field of view of the webcam is too small) and let it decide its own exposure, which resulted in a greatly over-exposed Moon. However, at least this meant that the eclipsed sector of the Moon was visible. Some darker areas can be seen in the eclipsed area in the first image, reflecting the fact that the Moon's surface is not uniform. The animation covers a time frame of about 8mins and shows the Earth's shadow slowly moving off the Moon's disc.
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| Partial lunar eclipse, 7th September 2006 (8pm BST) | The Earth's shadow moves across the Moon's face |
The next set of images show the total eclipse during the evening of 3rd March 2007. This eclipse had been eagerly anticipated, as the previous one was back in October 2004, and in the end it did not disappoint. As with the occultation the day before (click here to view it), the weather was cloudy until just before the event but then cleared to stay perfect for the entire duration. I mounted the digital camera on my equatorial tripod and set myself up to take one photo every 5mins during the partial phases and an assortment of shots during totality: that'll be just the 4hrs out in the garden then! Good job it wasn't too cold!
As is the case with most eclipses, the Moon did not pass exactly through the centre of the Earth's shadow - the next "central" eclipses after 2007 being on 15th June 2011 (partially visible in the UK) and 27th July 2018 (wholly visible in the UK). So, although the eclipse was truly total the Moon's surface was not evenly darkened as light scattered by the Earth's atmosphere makes the edge of the shadow rather diffuse: this can also been seen in the partial eclipse above. The Moon will likewise never be totally dark, the scattered light often turning it dark red or coppery coloured. By comparison, the partial phase of a solar eclipse is sharp because the Moon has no atmosphere and so there can be no scattering.
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| Total lunar eclipse, 3rd March 2007, showing the distinctive coppery colour and the area of lighter shadow | To demonstrate that it's the Moon that moves, not the shadow, this animation shows the motion of the Moon during totality relative to two stars (one each side). The time interval between images is 5mins. |
| As the Moon moves in a straight line through the Earth's curved shadow, the area which is lightened due to being near the edge of the shadow changes. This montage of two images, from the beginning and end of totality, shows this effect well: the lighter arc moves about 60deg anti-clockwise round the Moon's circumference in an hour. |  |
Photographing the full extent of a lunar eclipse is quite difficult, as the brightness of the subject varies enormously, as does the contrast between the eclipsed and non-eclipsed regions. I thus experimented by using a different exposure setting for the "inward" and "outward" phases. From the images I took I constructed two animations showing the advancing and retreating shadow line which I've put as links in the table below rather than placing them directly in this page. I also made movies from the same sequences (AVI format) so I've included them as well, although few systems will play them these days - take your pick! The exposure used for the inward phase turned out to be better, so this animation/movie is technically superior, but I present both sequences here as they show very clearly the different angle at which the eclipse departs from which it arrives - a consequence of the curvature of the shadow disc mentioned above.
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| Inward | Click here | Click here |
| Outward | Click here | Click here |
This eclipse took place in the early hours of the morning - from just before 2am to just after 5am, in fact - so little sleep was in prospect! Weather conditions in the previous week would have been perfect (clear and cold) but during the period in question cloud cover had been much greater. It tended to be fairly high and thin though so when a bright full Moon was visible through a haze in the early evening hopes were rising. This did not last, unfortunately, with the cloud continuing to thicken throughout the night. At 1am the sky was quite overcast so by the time the eclipse started (1:43am) visibility was not good and getting worse. I took a few shots of the advancing shadow line but they were decidedly indistinct. By just after 2am the Moon had more-or-less disappeared - eclipsed by cloud though, not the Earth's shadow! Occasional glimpses allowed one to keep track of progress in binoculars but photography was hopeless.
During totality itself (3:01 to 3:51) there were a few periods of lighter cloud but nothing actually visible in the sky. I decided to fire off some time exposures in the right general direction and was astounded to find that the camera picked up the dark Moon! Not only that, it saw Saturn and the star Regulus as well. This wasn't consistent though, so I think I was just lucky. Just after maximum eclipse (3:26) the sky did almost clear so I was able to take a few shots with the Moon actually in the viewfinder but this didn't last long. By 4am dense cloud had returned so I gave up a little after this and sought the comfort of my bed!
My photographic endeavours were thus not entirely in vain but it was not possible to get enough good images to replicate the animations of the 2007 eclipse above. However, they do show nicely that while the track of the 2007 eclipse was above the centre-line of the Earth's shadow (so the lighter areas were to top and left) this eclipse was below it (with lighter areas to right and below). It's difficult to say whether the colouration was any different, as of course the cloud could have affected this, but perhaps it was rather more browny-red than orangey-red this time.
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| Total lunar eclipse, 21st February 2008. This image is not very sharp as it is a stack of three 8sec time exposures at 400ASA, illustrating how dark the Moon actually was as a result of both the eclipse and the cloud cover. Taken between maximum and end of totality. | Images taken just after the start of totality and right at the end. Note the fuzziness (particularly in the backgrounds) caused by the cloud cover. |
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| A composite of the two smaller images above, showing that the proper motion of the Moon across the sky (and therefore through the Earth's shadow) causes the lighter area to move round its limb as totality proceeds: compare it with the similar image from 2007, above. The bright spot to the left is the planet Saturn, that to top right the star Regulus. | |
And that was it for totals until 21st December 2010: an unusually long wait. However, I was hoping it would provide some unusual photo opportunities as totality would begin just a few minutes before Moon-set: a dark red Moon against landscape would be very weird. Were it not for cloud (again!) the very large partial (81%) on 16th August 2008 would have been visible in the UK [maximum at 22:10 BST], just one half lunar-orbit after the total solar eclipse on 1st August. Anyone who has read my pages on eclipses might like to note that this partial was 177days after the total in 2008, as was the total in 2007 after the partial in 2006. The two totals illustrated above are separated by 354days (=2*177). And what happpened to the eclipse opportunity 177days after 3rd March 2007? There was actually a total eclipse then but it wasn't visible in the UK!
I had been looking forward to this eclipse for some time, not because it was spectacular (far from it!) but because it was unusual - it was a partially eclipsed Blue Moon. Those of you who have read my article on the subject will know that a Blue Moon is the second Full Moon in a month, and does not happen very often (about once every three years). An eclipsed Blue Moon happens much less frequently and, currently, a partially-eclipsed Blue Moon is even less common! Click here to find out more about Blue Moons.
| Things were not looking good early in the evening but, just for once, the sleet-clouds parted at exactly the right moment to allow me to get some good images when the eclipse was at its maximum extent (which was, however, only 8%!). The clouds prevented me from getting a sequence of images for a full animation, so I present here just one picture of the eclipse "as viewed". I was, however, able to demonstrate that the shadow did indeed move across the Moon - place the mouse pointer over the picture to see this. The frames, deliberately over-exposed to bring out the shadowed area better, were taken 13mins apart before maximum eclipse. The images also show that the shadow edge is curved. This is only to be expected of course, as it is the shadow of a round object - the Earth! |  |
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| Although the animation makes it appear that the shadow is moving, this is not the case: it is the Moon that moves. In this composite I have offset the later image by the correct distance the Moon moved in the 13mins and you can see that the shadowed sections join up to form a continuous curve. | By reducing the previous composite in size and adding a circle to represent the edge of the Earth's shadow (to the correct scale), the fact that the Moon was cutting just the very edge of the Earth's shadow during the eclipse becomes obvious. Given that the Moon is moving towards bottom left, it is also clear that the images were taken just before maximum eclipse, as stated. |
As I said above, partially-eclipsed Blue Moons are rather unusual so if you missed this one I'm afraid you've got a very long time to wait, as the next one isn't until 31st July 2129!! | |
This eclipse was unusual for two reasons - it was on the day of the northern winter solstice and it happened just as the Moon set. There has only been one other eclipse on the solstice since 1 A.D., and that was in 1638. You won't have to wait quite so long for the next one though - that will be in 2097. An eclipse at Moon-set was rather less auspicious, as the probability of cloud interfering with proceedings would be rather great. Still, I set the alarm for 6:30am, dressed warmly (two pairs of trousers, four top layers, a woolly hat & gloves), grabbed the camera and tripod and set off to see if I would be in luck.
Venus was shining brilliantly in the pre-dawn sky as I crunched through the frosty snow but prospects were not good - cloud on the horizon and much more all around. I caught a glimpse of the Moon between clouds, showing a distinct dark crescent taken out of its left-hand side, but not much more. It seemed possible a gap might be heading in the right direction though so I carried on to my viewing spot and set up the tripod. I was eventually rewarded with about 10mins of visibility, in which I took a few shots, but the hazy conditions meant they weren't particularly good. The cloud then set in solidly, so although I waited until the time of sunrise I didn't see anything else (except for two cats and a rather surprised small dog, that is!).
Despite the lack of success, it was interesting to experience the full geometry of the eclipse, with the rising Sun behind me throwing the Earth's shadow towards the Moon in front of me. Night-time eclipses are easier to see, but you don't get quite the same feeling of celestial alignment.
As I said, the pictures weren't brilliant, but here's two just for the record. They were taken only 5mins apart (at around 7:20am GMT) but the decrease in the non-eclipsed crescent is quite marked. Note also that the sky is beginning to lighten as dawn approaches. It is clear from the images that the eclipse was going to be total, as the eclipsed Moon looks just like a "normal" crescent Moon, as opposed to just having a bite taken out of it as in the cases of Sep. 2006 and Dec. 2009 above.
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The conditions for the 15th June 2011 total lunar eclipse, which was the mirror opposite in that it happened at Moon-rise, were even worse unfortunately - total cloud, in fact! I had hoped for a good photo-opportunity but it was not to be. Naturally, had the eclipse been the day before or the day after things would have been fine! 'Twas ever thus.
Despite being another total eclipse, this one was only ever going to be seen as a partial in the UK as totality had ended almost an hour before the Moon rose. However, I was keen to get some shots against the horizon so duly headed off up the church tower just before 4pm (much to the surprise of the church-warden who was in the church when I suddenly arrived!) with camera, tripod and binoculars slung round my neck - not an easy business in the narrow spiral staircase!
The Moon appeared quite suddenly out of the low mist, clearly still in eclipse, and slowly rose into the clear sky as it darkened at sunset. Clear skies mean low temperatures though, and camera batteries don't like low temperatures! I was thus able to get a number of pictures but not as many as I had hoped, as the camera just didn't like it (neither did my fingers!). As with the December eclipse in 2010, it was interesting to experience the full geometry of the eclipse, but now it was with the setting Sun making the western horizon glow pink as the Moon rose.
The animation is constructed from a sequence of shots taken a few minutes apart, and shows the eclipsed sector slowly decreasing in size as the Moon rises, brightening as it does so against the darkening sky.
Just for once, this was a total eclipse visible for its entire duration from the UK and not at either Moon-rise or Moon-set. It was interesting from a statistical standpoint as the Moon would be at perigee (its nearest point to the Earth on a given orbit) during the eclipse: a circumstance often, but incorrectly, called a Supermoon (see my article on the subject in the Theory section!). This combination is rather unusual - the last case visible in the UK was in 1979 and the next won't be until 2033 - but it has no particular astronomical significance. The rather serious downside was that maximum totality was at 3:47am! Yawn! However, the weather forecast was good and so I set out at around 1am for my viewing site (surveyed the previous day) with the car loaded up with camera equipment and plenty of warm clothing!
Things are never simple though, and in this case the complicating factor was unexpected amounts of cloud - my idea of taking a shot every 5mins to construct a full animation thus went out of the window. On the other hand, this might have been a blessing in disguise as, taking into account exposure bracketing (both using the camera's "auto-bracket" facility and by metering off various parts of the Moon for best effect), I captured well in excess of 200 separate images as it was! Fortunately, although the cloud cover was complete for long periods, there were also enough breaks and clear intervals to enable me to get a usable selection of pictures, particularly of totality and the progress of the shadow from totality to the end of the eclipse. I eventually got home around 6am, so it was a long night!
 | The partial phase of the eclipse was supposed to start at 2:07am but was actually well under way in the first picture I was able to take (once clouds had cleared sufficiently) at 2:06am, shown here. This discrepancy was probably caused by the assumption made about the size of the Earth's shadow when making the timing predictions. Unlike the Moon's shadow during a solar eclipse, which has well-defined edges, the Earth's shadow is somewhat "fuzzy" due to the influence of its atmosphere. The extent of this fuzziness can only be estimated rather than be accurately known in advance, and there are two well-known "rules of thumb" for doing this. However, reality may not agree with the estimate! This can be particularly true if there has been disruption in the atmosphere, and indeed large-scale volcanic eruptions in the weeks prior to the eclipse were presumed to have thrown large amounts of dust and other particles to high altitudes. This also had other consequences, as we shall see. I was then able to take further pictures for another 20mins before the clouds closed in completely, which I have made into an animation starting with an entirely non-eclipsed Moon taken somewhat earlier. Click or tap on the image to start (or restart) it and again to reset it. |
| Fortunately, conditions began to improve around 3am so that after a slightly worrying 35mins of total obscuration the Moon came into view again with just a crescent left un-eclipsed. The eclipsed segment was still visible though, its deep red colour contrasting starkly with the almost white un-eclipsed section: the view at 3:05am is shown here. Note that the boundary between the eclipsed and un-eclipsed segments is neither distinct (as mentioned above) nor uniformly coloured. In particular, there is a beautiful band of blue shading into violet between the two segments. This is caused by the presence of ozone high in the Earth's atmosphere, which absorbs much of the red light passing through it. The "turquoise fringe" is not always visible, as it depends on atmospheric conditions, so I was delighted to have been able to capture it on this occasion. |  |
 | Note also that the angle the boundary makes with the Moon's disc has rotated considerably as compared to the early partial phase shown earlier. This is because the eclipse was not exactly central i.e. the Moon did not pass directly through the centre of the Earth's shadow. In fact, it passed below centre and so although the first contact between the Moon and the shadow was at "top left", as the Moon travelled deeper into the shadow the boundary moved round to track the edge of the (circular) shadow. The animation here should make this clearer - click or tap on the image to start (or restart) it and again to reset it. The sequence of frames runs round twice - once with the shadow visible, to show how the rotation of the boundary comes about, and once with it not visible (as is truly the case) to show the situation "as seen". [Note that the colours are arbitrary! Blue represents the Earth's shadow, green the un-eclipsed part of the Moon and red the eclipsed part. The scale is approximately correct, however.] |
| The Moon then disappeared for a further 25mins so by the time it came into view again at 3:30am we were well into totality - as shown here. Note that the Moon's colour is very dark towards top-right and almost white at bottom-left. As shown by the animation, even during totality the bottom-left part of the Moon was very close to the shadow edge. Due to the fuzziness of this edge, as explained above, those parts of the Moon near to it will be partially illuminated by scattered light while those closer to the centre will be fully dark. Note also that the overall level of "darkness" is greater than for the other total eclipses on this page. This is not because I under-exposed the shot but was actually a real effect, noted by other observers, presumed to be due to the excess of volcanic dust in the atmosphere mentioned above. This will absorb some of the light which would otherwise be scattered onto the Moon, making it darker. |  |
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| This shot was taken at maximum eclipse (3:47am). Even so, the bottom-left sector is still only pink rather than the deep red of those parts nearer the centre of the shadow. Because the Earth's shadow is only 23/4 times as large as the Moon, a lunar eclipse has to be very nearly central before the edge of the Moon is far enough away from the edge of the shadow for it not to be slightly illuminated by scattered light. | I continued to have good luck with the cloud cover so was able to take a sequence of beautiful shots as totality progressed. This one shows the situation at just after 4am - click or tap on it to show two further views at 4min intervals thereafter (and then back to the 4am view). Note that the left-hand limb of the Moon gets steadily brighter as time passes and it approaches the edge of the Earth's shadow, and also that the brighter section moves clockwise round the limb as demonstrated by the simulation above. |
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| And then I was presented with this shot - the "turquoise fringe" again, but this time heading out of totality and right on the Moon's limb. Perhaps even more beautiful than the inward view. | I was not, unfortunately, able to capture the end of totality (at 4:23am) as cloud had begun to gather again. This (at 4:18am) was the last shot I got for the next half hour. |
 | Skies did clear around 4:50am though, and I was then able to capture images right up to the end of totality, which again I have made into an animation. Click or tap on the image to start (or restart) it and again to reset it. As with the beginning of the partial phase, my observations differed from the predictions. There is still a definite "nick" out of the Moon's limb in the third-last image (easier to see in the original), which was taken at 5:31am as compared to the official end-of-eclipse timing of 5:27am. Also note the drastically different angle the shadow leaves the Moon's limb compared to the one at which it entered it, as demonstrated by the simulation. |
| And finally, to again prove that the Moon really does move relative to the stars, I made two wider-angle views of the situation at mid-eclipse and just before the clouds closed in before the end of totality. I had deliberately offset the Moon from the centre of the frame when taking these images as I had noticed two stars visible in each which could be used to align them. They can be seen to top right, and are un-named 7th magnitude stars in the constellation of Pisces. Click or tap on the image to swap between the views. Note how, as the Moon moves towards top-left and thereby approaches the edge of the Earth's shadow, the lighter area increases in brightness and also moves round the Moon's limb, as per the simulation. |  |
An additional advantage of having a pair of stars in the same field as the Moon is that their known angular separation will enable you to measure the apparent size of the Moon. To ensure maximum accuracy, I went back to the original image to do this and found that the stars were separated by 500pixels and the Moon was 1268pixels across. Given that the separation of the stars is given by StarryNight as 13' 18" this means that the Moon was 33' 43.7" across, which compares incredibly well with the size of 33' 44.0" calculated from the Moon's distance from my location at the time the picture was taken, as given by the astronomical calculation program Solex (354046km). The absolute maximum diameter of the Moon (as observed from the surface of the Earth) is 34' 7.5", and so it is clear that the eclipsed Moon was indeed at perigee. However, its centre-to-centre distance from the Earth (356879km) was greater than the "Supermoon limit" of 356709km (100.1% of the absolute minimum perigee distance) and so while the "Blood Red Supermoon", as it was hyped in the media, was certainly the former it was definitely not the latter!
All the images shown above were taken with the "long lens" Canon PowerShot SX60 HS camera bought specifically for the Faeroe Islands solar eclipse trip. It clearly needed to be mounted on a tripod, to ensure stability, but a standard photographic (i.e. alt-azimuth) tripod would be unsatisfactory for two reasons. Firstly, it would make tracking the Moon as it moved across the sky somewhat difficult, due to the need to adjust in both axes simultaneously and the lack of a "slow motion" or fine adjustment facility. Secondly (and perhaps less obviously), because of the curved path the Moon takes across the sky the observed disc of the Moon rotates quite considerably from rise to set - had you ever noticed this? - and so successive images taken using an alt-azimuth tripod would be skewed in a clockwise direction. This would give me problems when constructing animations, for example, where the rotation would distract from the movement of the shadowed area, or when comparing views taken at different times. An equatorial tripod makes tracking much easier, as only one axis needs to be adjusted and slow-motion drives are always available, and because of the way they work the orientation of the Moon in the viewfinder will stay fixed. The only downside is that the images taken are not, therefore, as seen "with the naked eye". However, while this might be an issue if they were being taken for their "scenic" quality, it does not really matter if they are being used for instructive purposes, as in this webpage.
Given that the view when using an equatorial mount is thus essentially arbitrary, as it does not reflect what an observer would actually see, I had to decide which particular (fixed) orientation to use for my final images. As one of my image-comparisons involved background stars (the one showing that the Moon moved during the eclipse) I chose to orientate these images as per the naked-eye view at the time of the first image of the pair and then to match all other views to the same orientation. The fact that the image in question was taken at mid-eclipse added to the logic of this choice.
The next lunar eclipse (theoretically!) visible from the UK was a small partial on 7th August 2017, but as it came to an end just as the Moon rose I didn't bother getting my binoculars out! The next sensibly visible event was a total eclipse on 27th July 2018, when totality ran from 8:30pm to 10:13pm BST. This was the longest total lunar eclipse of the 21st Century, as the Moon was close to apogee (and was therefore smaller and slower-moving than average) and passed very close to the centre of the Earth's shadow (and was therefore within the shadow for longer than usual). However, as the Moon did not rise at my location until some time after the eclipse had started, the opening partial phase and initial totality were not observable, and the whole spectacle was very low down on the horizon. Also, due to the time of day, it would be seen against a relatively bright background sky. Despite this, I was keen to observe as I hoped to get some interesting shots of the rising eclipsed Moon, which would be joined by Mars later on during the eclipse.
I was due to be out for the first part of the early evening so I packed all my photographic gear into my car, intending to stop off at my pre-surveyed viewing spot on the way home. However! Although the eclipse was in the middle of one of the hottest and driest periods in the East of England for 40 years, it was probably inevitable that a thunderstorm would be sparked off on just the wrong evening!! No observation was possible therefore - I didn't even stop, but just went straight home cursing my luck. There was an interesting theoretical quirk to this eclipse though, a so-called "Selenehelion", which I have analysed on a separate page: click here to read all about it.
The weather forecast for this eclipse looked reasonably hopeful, with a good chance of clear skies, but clear skies at night in January usually only mean one thing - cold! As I was already somewhat unwell, and given that maximum eclipse was at a little after 5am, I decided that spending several hours outside in below zero temperatures was not going to be sensible. I thus checked to see how much of the eclipse could be viewed directly from my home, and found that totality would be nicely visible directly from our front door! I thus resolved to rise at 4:15am and observe the last stages of the partial phase plus totality - with frequent trips back inside to warm up!
Having set up and aligned my tripod on the front step the night before I was thus in position just before 4:30am. Skies were reasonably clear so I remained hopeful. However! Having begun my imaging sequence it soon became obvious that the band of cloud moving south-east across the country had arrived rather earlier than I had hoped and by 4:45am it was beginning to block out the Moon. Things then got worse rather than better and by about 5am the sky was entirely clouded over and remained that way until I decided enough was enough at around 6am and headed back to my bed.
I had managed to get a few shots of the end of the partial phase though, and just one of totality through a slight gap in the cloud which I had seen approaching, so all was not lost.
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| These two were taken as I was checking the correct exposure to use so are only 1 minute apart (4:26 and 4:27). The advance of the Earth's shadow is, however, quite noticeable even in this short period. | |
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| I was then ready to begin my "one every 5 minutes" schedule. The image on the left is at 4:30am, and again shows a considerable advance of the shadow. By 4:35am (on the right) the reduced brightess from the uneclipsed portion of the Moon has allowed a delicate turquoise shading of the shadow edge to become visible. As with the September 2015 eclipse, this is caused by absorption of red light by the ozone layer at the edge of the Earth's atmosphere. | |
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| At 4:40am (on the left), just before full totality, the turquoise shading is well developed with just a small uneclipsed sector. Cloud then advanced rapidly unfortunately, so the image on the right, of totality at 4:59am, was the last I was able to get. The "turquoise fringe" has now become almost a cap on the head of the Man-in-the-Moon - quite a spectacular shot. It is also noticeable that the lower part of the Moon is much darker than the upper part, as this is the sector which was nearest to the centre of the Earth's shadow. | |
Had I been able to capture a full sequence of pictures of totality I had intended assembling them into an animation, as with some previous eclipses. Given the small number of shots conditions allowed me to collect however, this was not possible. I have therefore taken a different approach, making them into a video with fades between the images in order to "smooth over" the irregular time intervals between them. For a better effect I decided to start the "video animation" with a frame of the Full but uneclipsed Moon taken by a friend of mine in Derby - he had even less luck than I did later, as the clouds rolled in much sooner.
The video is presented as a link, not embedded, to leave more flexibility as to how it plays on viewers' systems. You will need to have a program capable of displaying MP4 videos, but this should not be a problem - I use the excellent, very popular (and free!) VLC media player.
Click on the link to play - Eclipse Movie
Note the interval between this eclipse and the one in January 2019 - 354 days, or two "eclipse seasons", as explained in my article on Eclipses in the Theory section. Note also the interval between this eclipse and the partial on 16th July 2019 for which I was clouded out - 177 days, or one eclipse season - and of course the 15 days (or one half lunar orbit) between this eclipse and the annular solar eclipse on Boxing Day. Nice to see that the maths really does work out as predicted!
I don't normally bother with Penumbral eclipses, as they are almost un-noticeable, but this one was very nearly a "total penumbral eclipse" (if you see what I mean!) and so I hoped that the part of the penumbral shadow nearest to the Earth's umbra would be dark enough to be more easily visible.
Just for once, skies were perfectly clear and so the rising Moon looked majestic as it appeared in the East - behind a clump of trees, of course! I kept an eye on it with binoculars but could see absolutely nothing different as the eclipse began, and for quite a time afterwards. The Moon had cleared the trees by 30mins before maximum eclipse, and I thought I could see a bit of shading, so I began to take my first set of photos at different exposures. I repeated the set at the time of maximum eclipse and at 30mins and 60mins after, by which time no shading could easily be seen - time to pack up!
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| Half an hour before maximum eclipse and the darkening to the lower right portion of the Moon's disc is quite noticeable. | At maximum eclipse the "near-umbral" shadow is very obvious, but the rest of the disc is effectively unchanged. |
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| Half an hour after maximum, and the darkening has decreased in intensity and moved round the limb as the Moon travels through the Earth's shadow. | One hour past maximum and although there is another hour to go yet the penumbral shadow is almost un-noticeable. |
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| An animation of the above frames. Click or tap on the image to start (or restart) the animation, click again to reset it. The movement of the shadow round the Moon's limb is particularly noticeable. | |
Not including penumbral eclipses, there won't be another major event visible from the UK until the total eclipses on 14th March & 7th September 2025 and 28th August 2026 but these cannot be seen in their entirely from my location as the Moon sets just before maximum eclipse in March 2025, rises only just before totality in September 2025 and sets before the eclipse ends in 2026! The total eclipse on 31st December 2028 is a little better as totality happens 40 minutes after the Moon has risen but that of 26th June 2029 will be difficult to observe as totality happens only 20 minutes before moonset. In fact, I will have to wait until 20th December 2029 for my next chance to see a complete total eclipse high in the sky! Hopefully that will be worth waiting for - rest assured I'll keep you updated.
