Luca Vanzella
The Major Lunar Standstill - a real, visual representation
The Major Lunar Standstill - a real, visual representation
by Alister Ling and Luca Vanzella
UPDATE: This image was published as a NASA Astronomy Picture of the Day!
Celebrating the northeastern and southeastern extremes of sunrise points (solstices) are familiar experiences to all casual skywatchers but the moonrise extremes (lunistices) mostly go unnoticed except to attentive observers. As the Moon’s orbit slowly regresses in an 18.6 year cycle, the span of moonrise points varies between two extremes: the minor and major lunar standstills. In a major lunar standstill, the extreme moonrise points are several degrees farther north and south than the sunrise ones. Inspired by an earlier project of creating a time slice of sunrises, we wanted to capture these events photographically in a manner both educationally and visually compelling.
Technically the Major Lunar Standstill is a point in time on the dates of the extreme north and south lunar declinations, both occurring in March 2025, but similar to solstices, it is best appreciated in the context of a period of observation. Any consistent phase would reveal the pattern, but a full Moon is the most eye-catching and stands out best in very wide images.
The period from the June 2024 solstice to the June 2025 solstice nicely surrounds the standstill, so we planned to shoot thirteen full moonrises and thirteen sunrises during that interval. Inspired by an earlier project that created a vertical time slice of sunrises, we realized we could assemble a similar composite to show how the greatest northern and southern positions of the Moon extend beyond those of the Sun during a Major Lunar Standstill.
Planning the Project
The concept was simple: just capture evening moonrises and morning sunrises on the full Moon dates from the June 2024 solstice to the June 2025 solstice. However, years of shooting sunrises and moonrises in the Edmonton area had taught us two things:
One, it is possible to shoot thirteen consecutive sunrises spaced about a month apart within a few days of desired dates. Alberta is a sunny province and clear skies at sunrise are common. Plus, the sunrise azimuth changes only slightly from day to day, even at the equinoxes, and in these panoramic images it’s hardly noticeable.
Two, it is not possible to shoot thirteen consecutive full moonrises because the probability of a clear sky precisely a few minutes after moonrise on the exact date of a full Moon is perhaps 50%. Since the moonrise azimuth changes significantly from day to day, even shooting one day on either side of the target date puts the Moon out of place (especially at the extremes).
To maintain a high degree of authenticity, we came up with a plan to capture moonrises beforehand that could serve as proxies for the target moonrises that would be obscured by cloudy skies. Each substitute moonrise needed these attributes:
- Very similar moonrise azimuth (plus or minus 2°).
- Very similar moonrise time with respect to sunset (proxy for sky brightness).
- Very similar moonrise month (proxy for ground conditions).
- Very similar moon phase (full or plus or minus one day).
We examined the circumstances of every full or near full moonrise from January 2022 to May 2024 and selected those events that met the above attributes. This two and half year period is approximately the size of the lunistice period in which the extreme moonrise azimuths remain essentially the same (similar to solstice sunrise azimuths). We shot as many of these proxy moonrises as possible given our personal schedules and clear skies permitting.
Capturing the Images
At first we considered using a fisheye lens for the project, but at that image scale, the Moon’s size was only a few pixels across, resulting in a featureless blob when enlarged to a decent display dimension. A 10mm focal length lens could still resolve the key maria, presenting us with its recognizable face should we produce a poster-sized print. Consequently the field of view was too small to cover the full range in azimuth, forcing us to shoot two image panels which we would later stitch into panoramas.
For sunrises, each panel consisted of a 3x1EV bracket, for example 1/125, 1/250, 1/500 of a second. For moonrises, each panel consisted of a 6x2EV bracket (2, 1/2, 1/8, 1/30, 1/125, 1/500 second) to cover the enormous range of brightness from grass through sky to the sunlit Moon. For very dark moonrises, we could simplify by taking pre-rise images bracketed for sky and foreground lighting plus a second bracket exposed for the Moon and wispy clouds.
Since the sunrise azimuth over the course of a year is essentially the same year after year, we decided to capture the sunrises from January to December 2022, with two in June 2022, as close as possible to the dates of the target moonrises, and as expected, we were successful in capturing all 13 sunrises in consecutive months.
We shot 24 proxy moonrises from January 2022 to May 2024 and then all 13 target moonrises from June 2024 to June 2025.
Fun fact - we captured a total of 50 events: 24 proxy moonrises, 13 target moonrises, (5 had clear skies, 8 had cloudy skies), and 13 sunrises.
Processing the Images
The panorama brackets were stitched, fused and blended in Hugin. For the dark moonrises, the pre-rise brackets were stitched, fused and blended in Hugin while keeping the Moon panels separate but receiving the identical remapping to the equirectangular projection; then the final panorama was composited in GIMP.
Cosmetic edits were applied to erase hot and dead pixels and in some of the dark moonrise images, we erased construction floodlights in the foreground since these were distracting or might be confused with the Moon itself.
The goal was to have twenty six panoramas with virtually identical image frames. This would be important for the final composite image and for the movie animating the image.
For each session, no matter how careful we were, tiny shifts in camera placement and aim resulted in subtly different panorama frames, enough to be disturbing when lined up in our composite, especially at the seam. Every frame varied slightly in width, tilt, horizon skew and projection distortion. Even if we had avoided the need for panoramas by using a fisheye lens, we couldn’t prevent the mismatches at the center due to the sensitivity of the inherent distortion on position and aim. People really find it jarring when horizontal and edge features don’t line up.
One sunrise panorama was selected as the fixed, base image. All other panoramas were adjusted to match the base image with a four step process in GIMP: scale, align, rotate, and a cage transform to rectify nonlinear distortions. In the end we could overlay them to a precision of a handful of pixels.
Assembling the Final Composite
The principal result of this project is a vertical time slice of thirteen moonrise and thirteen sunrise images from June 2024 to June 2025, to visually depict the change in moonrise/sunrise position over a year and to illustrate that the greatest northern and southern positions of the Moon extend beyond those of the Sun during a Major Lunar Standstill.
Since we captured both sunrises and moonrises, we also produced two other images:
A vertical time slice of full moonrise positions over a year: Major Lunar Standstill - Moonrises
A vertical time slice of sunrise positions over a year: Major Lunar Standstill - Sunrises
The final assembly took place in GIMP by importing all moonrise and sunrise images into separate layers. These were aligned to the fixed, base sunrise image then cropped two different ways: narrow strips centered on the horizon for the final composite images, and larger rectangles that excluded edge artifacts for the movie.
Animating the Final Image
We also made a movie that animates the Major Lunar Standstill by showing the sequence of moonrise and sunrise images and how they were cropped and stacked to make the vertical time slices.
Conclusion
Had it been clear, you would have seen the Major Lunar Standstill similar to this. It might be argued that the final result is not “real” due to our use of proxies. True, but using cloudy panels hurt the educational value and acquiring a full set with clear skies, although theoretically possible, is practically speaking quite unlikely for sites in the mid-latitudes. Our image is one that observers can instantly relate to.
Image Acquisition
Camera: T3i / Canon 60D
Lens: Canon EF-S 10-18mm @ 10mm
Settings: ISO 200, Daylight WB, f/4.5
Sunrises: 3x1EV bracket, e.g.: 1/125, 1/250, 1/500 sec
Moonrises: 6x2EV bracket, e.g.: 2, 1/2, 1/8, 1/30, 1/125, 1/500 sec
Event Data
Here's the essential data from the 26 events. Each sunrise was planned to capture the Sun about 0.5° above the horizon, while each moonrise was planned to capture the Moon about 2.5° above the horizon.
Target Moonrise Moon D | Sunrise Sun D Date Actual Az Az | Actual Az Az
2024 06 21 2024 06 21 151.2 0.0 | 2022 06 19 46.6 -0.1
2024 07 21 2024 07 21 134.5 0.0 | 2022 07 21 52.7 0.2
2024 08 19 2022 08 12 118.5 1.1 | 2022 08 19 67.2 0.2
2024 09 17 2022 09 10 101.8 2.6 | 2022 09 17 85.3 0.4
2024 10 17 2024 10 17 69.5 0.0 | 2022 10 17 104.8 0.3
2024 11 15 2023 11 26 54.8 0.1 | 2022 11 14 120.6 0.8
2024 12 15 2023 11 28 44.9 1.4 | 2022 12 13 130.0 0.3
2025 01 13 2025 01 13 49.1 0.0 | 2022 01 16 125.4 1.0
2025 02 12 2025 02 17 71.1 0.0 | 2022 02 11 112.6 -0.7
2025 03 14 2023 04 05 101.6 3.8 | 2022 03 16 91.6 1.2
2025 04 12 2025 04 12 115.7 1.0 | 2022 04 11 74.6 -0.8
2025 05 12 2022 07 13 142.7 3.0 | 2022 05 12 57.0 -0.1
2025 06 11 2024 05 25 151.0 0.0 | 2022 06 12 47.1 0.1
Moon Az = Moonrise Azimuth
D Az = Delta from Target Moon Az (degrees)
The Major Lunar Standstill - a real, visual representation
The Major Lunar Standstill - a real, visual representation
by Alister Ling and Luca Vanzella
UPDATE: This image was published as a NASA Astronomy Picture of the Day!
Celebrating the northeastern and southeastern extremes of sunrise points (solstices) are familiar experiences to all casual skywatchers but the moonrise extremes (lunistices) mostly go unnoticed except to attentive observers. As the Moon’s orbit slowly regresses in an 18.6 year cycle, the span of moonrise points varies between two extremes: the minor and major lunar standstills. In a major lunar standstill, the extreme moonrise points are several degrees farther north and south than the sunrise ones. Inspired by an earlier project of creating a time slice of sunrises, we wanted to capture these events photographically in a manner both educationally and visually compelling.
Technically the Major Lunar Standstill is a point in time on the dates of the extreme north and south lunar declinations, both occurring in March 2025, but similar to solstices, it is best appreciated in the context of a period of observation. Any consistent phase would reveal the pattern, but a full Moon is the most eye-catching and stands out best in very wide images.
The period from the June 2024 solstice to the June 2025 solstice nicely surrounds the standstill, so we planned to shoot thirteen full moonrises and thirteen sunrises during that interval. Inspired by an earlier project that created a vertical time slice of sunrises, we realized we could assemble a similar composite to show how the greatest northern and southern positions of the Moon extend beyond those of the Sun during a Major Lunar Standstill.
Planning the Project
The concept was simple: just capture evening moonrises and morning sunrises on the full Moon dates from the June 2024 solstice to the June 2025 solstice. However, years of shooting sunrises and moonrises in the Edmonton area had taught us two things:
One, it is possible to shoot thirteen consecutive sunrises spaced about a month apart within a few days of desired dates. Alberta is a sunny province and clear skies at sunrise are common. Plus, the sunrise azimuth changes only slightly from day to day, even at the equinoxes, and in these panoramic images it’s hardly noticeable.
Two, it is not possible to shoot thirteen consecutive full moonrises because the probability of a clear sky precisely a few minutes after moonrise on the exact date of a full Moon is perhaps 50%. Since the moonrise azimuth changes significantly from day to day, even shooting one day on either side of the target date puts the Moon out of place (especially at the extremes).
To maintain a high degree of authenticity, we came up with a plan to capture moonrises beforehand that could serve as proxies for the target moonrises that would be obscured by cloudy skies. Each substitute moonrise needed these attributes:
- Very similar moonrise azimuth (plus or minus 2°).
- Very similar moonrise time with respect to sunset (proxy for sky brightness).
- Very similar moonrise month (proxy for ground conditions).
- Very similar moon phase (full or plus or minus one day).
We examined the circumstances of every full or near full moonrise from January 2022 to May 2024 and selected those events that met the above attributes. This two and half year period is approximately the size of the lunistice period in which the extreme moonrise azimuths remain essentially the same (similar to solstice sunrise azimuths). We shot as many of these proxy moonrises as possible given our personal schedules and clear skies permitting.
Capturing the Images
At first we considered using a fisheye lens for the project, but at that image scale, the Moon’s size was only a few pixels across, resulting in a featureless blob when enlarged to a decent display dimension. A 10mm focal length lens could still resolve the key maria, presenting us with its recognizable face should we produce a poster-sized print. Consequently the field of view was too small to cover the full range in azimuth, forcing us to shoot two image panels which we would later stitch into panoramas.
For sunrises, each panel consisted of a 3x1EV bracket, for example 1/125, 1/250, 1/500 of a second. For moonrises, each panel consisted of a 6x2EV bracket (2, 1/2, 1/8, 1/30, 1/125, 1/500 second) to cover the enormous range of brightness from grass through sky to the sunlit Moon. For very dark moonrises, we could simplify by taking pre-rise images bracketed for sky and foreground lighting plus a second bracket exposed for the Moon and wispy clouds.
Since the sunrise azimuth over the course of a year is essentially the same year after year, we decided to capture the sunrises from January to December 2022, with two in June 2022, as close as possible to the dates of the target moonrises, and as expected, we were successful in capturing all 13 sunrises in consecutive months.
We shot 24 proxy moonrises from January 2022 to May 2024 and then all 13 target moonrises from June 2024 to June 2025.
Fun fact - we captured a total of 50 events: 24 proxy moonrises, 13 target moonrises, (5 had clear skies, 8 had cloudy skies), and 13 sunrises.
Processing the Images
The panorama brackets were stitched, fused and blended in Hugin. For the dark moonrises, the pre-rise brackets were stitched, fused and blended in Hugin while keeping the Moon panels separate but receiving the identical remapping to the equirectangular projection; then the final panorama was composited in GIMP.
Cosmetic edits were applied to erase hot and dead pixels and in some of the dark moonrise images, we erased construction floodlights in the foreground since these were distracting or might be confused with the Moon itself.
The goal was to have twenty six panoramas with virtually identical image frames. This would be important for the final composite image and for the movie animating the image.
For each session, no matter how careful we were, tiny shifts in camera placement and aim resulted in subtly different panorama frames, enough to be disturbing when lined up in our composite, especially at the seam. Every frame varied slightly in width, tilt, horizon skew and projection distortion. Even if we had avoided the need for panoramas by using a fisheye lens, we couldn’t prevent the mismatches at the center due to the sensitivity of the inherent distortion on position and aim. People really find it jarring when horizontal and edge features don’t line up.
One sunrise panorama was selected as the fixed, base image. All other panoramas were adjusted to match the base image with a four step process in GIMP: scale, align, rotate, and a cage transform to rectify nonlinear distortions. In the end we could overlay them to a precision of a handful of pixels.
Assembling the Final Composite
The principal result of this project is a vertical time slice of thirteen moonrise and thirteen sunrise images from June 2024 to June 2025, to visually depict the change in moonrise/sunrise position over a year and to illustrate that the greatest northern and southern positions of the Moon extend beyond those of the Sun during a Major Lunar Standstill.
Since we captured both sunrises and moonrises, we also produced two other images:
A vertical time slice of full moonrise positions over a year: Major Lunar Standstill - Moonrises
A vertical time slice of sunrise positions over a year: Major Lunar Standstill - Sunrises
The final assembly took place in GIMP by importing all moonrise and sunrise images into separate layers. These were aligned to the fixed, base sunrise image then cropped two different ways: narrow strips centered on the horizon for the final composite images, and larger rectangles that excluded edge artifacts for the movie.
Animating the Final Image
We also made a movie that animates the Major Lunar Standstill by showing the sequence of moonrise and sunrise images and how they were cropped and stacked to make the vertical time slices.
Conclusion
Had it been clear, you would have seen the Major Lunar Standstill similar to this. It might be argued that the final result is not “real” due to our use of proxies. True, but using cloudy panels hurt the educational value and acquiring a full set with clear skies, although theoretically possible, is practically speaking quite unlikely for sites in the mid-latitudes. Our image is one that observers can instantly relate to.
Image Acquisition
Camera: T3i / Canon 60D
Lens: Canon EF-S 10-18mm @ 10mm
Settings: ISO 200, Daylight WB, f/4.5
Sunrises: 3x1EV bracket, e.g.: 1/125, 1/250, 1/500 sec
Moonrises: 6x2EV bracket, e.g.: 2, 1/2, 1/8, 1/30, 1/125, 1/500 sec
Event Data
Here's the essential data from the 26 events. Each sunrise was planned to capture the Sun about 0.5° above the horizon, while each moonrise was planned to capture the Moon about 2.5° above the horizon.
Target Moonrise Moon D | Sunrise Sun D Date Actual Az Az | Actual Az Az
2024 06 21 2024 06 21 151.2 0.0 | 2022 06 19 46.6 -0.1
2024 07 21 2024 07 21 134.5 0.0 | 2022 07 21 52.7 0.2
2024 08 19 2022 08 12 118.5 1.1 | 2022 08 19 67.2 0.2
2024 09 17 2022 09 10 101.8 2.6 | 2022 09 17 85.3 0.4
2024 10 17 2024 10 17 69.5 0.0 | 2022 10 17 104.8 0.3
2024 11 15 2023 11 26 54.8 0.1 | 2022 11 14 120.6 0.8
2024 12 15 2023 11 28 44.9 1.4 | 2022 12 13 130.0 0.3
2025 01 13 2025 01 13 49.1 0.0 | 2022 01 16 125.4 1.0
2025 02 12 2025 02 17 71.1 0.0 | 2022 02 11 112.6 -0.7
2025 03 14 2023 04 05 101.6 3.8 | 2022 03 16 91.6 1.2
2025 04 12 2025 04 12 115.7 1.0 | 2022 04 11 74.6 -0.8
2025 05 12 2022 07 13 142.7 3.0 | 2022 05 12 57.0 -0.1
2025 06 11 2024 05 25 151.0 0.0 | 2022 06 12 47.1 0.1
Moon Az = Moonrise Azimuth
D Az = Delta from Target Moon Az (degrees)