Annular Solar Eclipse of 1966 May 20
in Greece or Turkey
On 1966 May 20, Greece and Turkey got a peek at a splendid pearled annular solar eclipse. On this occasion it was possible to accurately measure the path position of the Moon’s antumbra and to control the lunar limb profile. Such observations were already executed during the hybrid solar eclipses on 1912 April 17 near Paris in France and 1930 April 28 near Camptonville in California, both eclipses belonging to the same saros 137. The next eclipse of this saros, the 1948 May 9 annular in Japan, provided the exact same opportunity.
In Greece, most of the groups went to the Saronida-Anávissos area, south of Athens. In Turkey, they chose the town of Ayvalik, to the northeast of the greek Lesbos island.
North American and Italian group in Saronida (Greece):
Robert Morris, then a graduate student at Imperial College in London, relied on the eclipse predictions from the USNO, see below, to prepare his trip. Travelling on an Athens-Sounion bus, and not knowing exactly where the centerline was, Bob saw a group of perhaps 40 astronomers and a dozen telescopes in a small compound on a hillside in the Saronida-Anávissos area and asked to be let off the bus. It turned out that famed solar astronomer Donald Menzel† was on site and many years later Bob learned that Jean Meeus, well known for his spherical and mathematical astronomy books, was only a few kilometers away and inland! The weather was absolutely perfect.
Courtesy of L. Robert Morris
On the map below one can see that the centerline predicted by the USNO was roughly one kilometer away from the centerline computed nowadays. The USNO predictions, made for a ΔT value of 36 seconds, were recomputed for the correct ΔT value of 36.9 seconds. The centerline computed by Jean Meeus for the same ΔT value is within a hundred meters from the one computed by the USNO. After seeing the group of well-known atronomers Donald Menzel† and Giovanni Righini†, it turned out that Robert ended on a hillside about 200 meters away from the USNO centerline (1.2 kilometers from the real centerline), where they had setup their camp. The group led by Jean Meeus was about 300 meters further inland.
L. Robert Morris, Donald Menzel† and Giovanni Righini† viewing location in Saronida, Greece
The picture below was taken during the morning on 1966 May 20th by Robert Morris from the hillside where the group was located.
Arsidha island from the hillside viewing compound occupied by Menzel†, Morris, and others (courtesy of L. Robert Morris, 1966 May 20th)
Google Earth simulated view that helped to locate accurately the viewing site
The tripod shadow reflects the fact that the picture below was taken before first contact, the Aegean sea is on the left, and the top of the hill, the south side of which was the compound site, is visible at the right.
In center, the tripod and binocular assembly used for Morris’s eclipse photos (courtesy of L. Robert Morris, 1966 May 20th)
Baily’s beads simulation from Saronida, the viewing location of L. Robert Morris in Greece
(created with Solar Eclipse Maestro)
The pictures below were taken by Robert Morris from a hillside in Saronida near Anávissos, Greece. From the photographer: the Sun/Moon image was projected by one half of a 7x35 binocular into the lens of a Minolta A2 35mm rangefinder camera. The alignment of the assembly was not perfect and the aiming was done by pointing the camera/binocular assembly roughly at the Sun. The camera viewfinder was not used. The solar image, perhaps 1/8" wide, was far off center on the Kodakchrome 64 slide film, hence the ovoid shape and chromatic aberration.
Exposure was that specified in the Kodak booklet for partial phases, with two Kodak ND filters mounted on the binocular objective. Probably 1/200 or 1/400 sec (unique to Minolta A2) at the required aperture. For some reason, a single ND filter of the required density was not available in London, and that proved to be the salvation of the imaging. I had a hunch that the final stage of the eclipse needed more exposure and I removed one filter! That gave perfect exposure for the two broken crescents and the broken ring.
The assembly was mounted on a flimsy tripod, and in between the "before" crescent, the "diamond necklace", and the "after" crescent, I had to wind the film with a ratchet lever, trying not to move the camera, then watch the Sun though a welder’s glass, and press a cable release at the right time.
The three single exposures, one chance only for each, taken a few seconds apart, worked!
Photographs courtesy of L. Robert Morris – Baily’s beads simulation created by Xavier M. Jubier with Solar Eclipse Maestro
Original photograph, courtesy of L. Robert Morris, inserted at the center of the Baily’s beads simulation created by Xavier M. Jubier with Solar Eclipse Maestro
It is truly remarkable to see how well the Baily’s beads simulations match the photographs taken on 1966 May 20th by Robert Morris in Saronida, Greece. All the features are in place, which suggests that the lunar limb profile and computations are as correct as they can be.
On the map below one can see the area around the centerline near the Greek city of Saronida where a group of Dutch and Flemish amateur astronomers led by Jean Meeus made observations. The group was located very near the centerline, displayed in turquoise, computed by Jean Meeus.
Jean Meeus viewing location in Saronida, Greece
Lesbos island group (Greece):
On the map below one can see the area around the centerline near the Greek city of Mistegna on Lesbos island. The centerline computed by the Yale University Observatory is displayed in turquoise.
Casual Astronomers likely viewing location near Mistegna, Lesbos island in Greece
Letter from the Yale University Observatory.
Turkish and Swiss group in Ayvalik (Turkey):
On the map below one can see the area around the centerline near the Turkish city of Ayvalik.
Atila Özgüç viewing location near Ayvalik, Turkey
The pictures below were taken by Atila Özgüç near Ayvalik, Turkey. Atila provided a very nice and interesting video, where unfortunately the eclipse sequence is highly overexposed and can not be used efficiently.
Viewing location (courtesy of Atila Özgüç)
Baily’s beads simulation from Ayvalik, the viewing location of Atila Özgüç in Turkey
(created with Solar Eclipse Maestro)
Max Waldmeier†, from the ETH and the Swiss Federal Observatory in Zürich, happens to be born on 18 April 1912, that is just one day after the remarkable 1912 April 17 hybrid solar eclipse or one exeligmos before ASE 1966!
Diamond necklace (courtesy of Max Waldmeier†)
Again the Baily’s beads simulation matches the photograph taken on 1966 May 20th by Max Waldmeier† in Ayvalik, Turkey. All the features are in place, which suggests again that the lunar limb profile and computations are as correct as they can be.