Qualla: Solar eclipse of May 20, 1966

Solar eclipse of May 20, 1966: Introduction

Sun, 14 Jun 2026 00:00:00 GMT

Photo credit SockPuppetForTomruen at English Wikipedia, Public domain. For roughly five seconds, the Sun became a ring. On the morning of Friday, May 20, 1966, the Moon slid almost perfectly across the Sun's face but fell just short of covering it, leaving a thin blazing circle suspended over the Aegean. This was an annular eclipse with a magnitude of 0.9991 — so close to total that the band of annularity narrowed to barely three kilometers wide. To stand inside that sliver as the ring closed and reopened was to occupy one of the most precisely defined patches of ground on the planet that day. And the place to be was the Turkish coastal town of Ayvalık.

Image: SockPuppetForTomruen at English Wikipedia | Public domain

Solar eclipse of May 20, 1966: A Ring Drawn Across the World

Sun, 14 Jun 2026 00:00:00 GMT

Photo credit Tomruen, CC BY-SA 4.0. The Moon's shadow began its work in West Africa at dawn. The path of annularity touched down over Guinea — sweeping across its capital, Conakry — then raced northeast across Mali, Algeria, and Libya before crossing the Mediterranean into Greece and Turkey. From there it pressed o...

Image: Tomruen | CC BY-SA 4.0

Solar eclipse of May 20, 1966: Why Astronomers Came to Ayvalık

Sun, 14 Jun 2026 00:00:00 GMT

Photo credit Direção Nacional Metereologia e Geofisica DNMG, Public domain. An eclipse this close to total is a gift to science, and astronomers knew it. When the Moon nearly fills the Sun's disk, the apex of its umbral shadow grazes the Earth's surface and the edges of the two bodies seem to touch. That allowed observers to catch Baily's beads — the gli...

Image: Direção Nacional Metereologia e Geofisica DNMG | Public domain

Solar eclipse of May 20, 1966: The Crown That Never Came

Sun, 14 Jun 2026 00:00:00 GMT

Photo credit Direção Nacional Metereologia e Geofisica DNMG, Public domain. There was a tantalizing possibility. Because this eclipse came so achingly close to total, some predicted that the Sun's corona — the pearly halo of outer atmosphere reserved for total eclipses — might briefly flash into view. A team crossed to Lesbos hoping to witness it. They w...

Image: Direção Nacional Metereologia e Geofisica DNMG | Public domain

Solar eclipse of May 20, 1966: A Link in an Ancient Chain

Sun, 14 Jun 2026 00:00:00 GMT

Photo credit Kimon Berlin, CC BY-SA 2.0. No eclipse stands alone. This one belonged to Solar Saros 137, a family of eclipses recurring roughly every eighteen years, and several of its siblings had shared that same razor-thin geometry near magnitude 1. The annular eclipse of May 9, 1948 had been watched from Rebun Island...

Image: Kimon Berlin | CC BY-SA 2.0