Solar eclipse of October 3, 1986
Encyclopedia
A total solar eclipse
occurred on October 3, 1986. It was a hybrid event (normally, an eclipse which is annular for most of its duration, but with totality either at the beginning, end or at sometime during the eclipse) that did not officially satisfy the definition of totality. Totality occurred for a very short time (calculated at 0.2 seconds) in an area in the Atlantic Ocean
, just east of the southern tip of Greenland
. The path, on the surface of the Earth, was a narrow, tapered, horse-shoe, and visible only from a thin strip between Iceland
and Greenland. The eclipse's very short maximum duration was the result of the lunar and solar topocentically viewed diameters being virtually identical. At maximum eclipse the solar elevation was about 6°.
- a diamond in the tiara - formed at the 3rd contact limb 0.2s before 2nd contact so that totality did not officially take place). The nine flyers who viewed this eclipse by air were rewarded to a ring of chromospheric light (a "diamond tiara" as opposed to the "diamond ring" effect usually seen at 2nd and 3rd contacts of a normal total eclipse).
Solar eclipse
As seen from the Earth, a solar eclipse occurs when the Moon passes between the Sun and the Earth, and the Moon fully or partially blocks the Sun as viewed from a location on Earth. This can happen only during a new moon, when the Sun and the Moon are in conjunction as seen from Earth. At least...
occurred on October 3, 1986. It was a hybrid event (normally, an eclipse which is annular for most of its duration, but with totality either at the beginning, end or at sometime during the eclipse) that did not officially satisfy the definition of totality. Totality occurred for a very short time (calculated at 0.2 seconds) in an area in the Atlantic Ocean
Atlantic Ocean
The Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about , it covers approximately 20% of the Earth's surface and about 26% of its water surface area...
, just east of the southern tip of Greenland
Greenland
Greenland is an autonomous country within the Kingdom of Denmark, located between the Arctic and Atlantic Oceans, east of the Canadian Arctic Archipelago. Though physiographically a part of the continent of North America, Greenland has been politically and culturally associated with Europe for...
. The path, on the surface of the Earth, was a narrow, tapered, horse-shoe, and visible only from a thin strip between Iceland
Iceland
Iceland , described as the Republic of Iceland, is a Nordic and European island country in the North Atlantic Ocean, on the Mid-Atlantic Ridge. Iceland also refers to the main island of the country, which contains almost all the population and almost all the land area. The country has a population...
and Greenland. The eclipse's very short maximum duration was the result of the lunar and solar topocentically viewed diameters being virtually identical. At maximum eclipse the solar elevation was about 6°.
Observations
A single aircraft deployed to the region to intercept the eclipse at totality. By intercepting the umbral cone at 44,000 feet, they get closer to the moon by 80 miles relative to a sea level site, and grew the Moon's diameter with respect to the Sun by a 0.7 arc seconds. Calculations using a smooth lunar rim at the aircraft's altitude showed a possible 1.5 second maximum duration. This is reduced to negative 0.2 seconds when the true lunar rim is applied. The eclipse duration on the moving aircraft was estimated at between 5 and 6 seconds by the witnesses. At 44,000 feet, the eclipse was not annular, though some have argued it was not total as the photosphere was never instantaneously completely extinguished (as a Baily's beadsBaily's beads
As the moon "grazes" by the Sun during a solar eclipse, the rugged lunar limb topography allows beads of sunlight to shine through in some places, and not in others. This effect is called Baily's beads in honor of Francis Baily who first provided an exact explanation of the phenomenon in 1836...
- a diamond in the tiara - formed at the 3rd contact limb 0.2s before 2nd contact so that totality did not officially take place). The nine flyers who viewed this eclipse by air were rewarded to a ring of chromospheric light (a "diamond tiara" as opposed to the "diamond ring" effect usually seen at 2nd and 3rd contacts of a normal total eclipse).