An annular solar eclipse took place at the Moon's descending node of the orbit on Monday, April 18, 1977. A solar eclipse occurs when the

Moon The Moon is Earth's only natural satellite. It is the fifth largest satellite in the Solar System and the largest and most massive relative to its parent planet, with a diameter about one-quarter that of Earth (comparable to the width of ...

passes between

Earth Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's surfa ...

and the

Sun The Sun is the star at the center of the Solar System. It is a nearly perfect ball of hot plasma, heated to incandescence by nuclear fusion reactions in its core. The Sun radiates this energy mainly as light, ultraviolet, and infrared radi ...

, thereby totally or partly obscuring the image of the Sun for a viewer on Earth. An annular solar eclipse occurs when the Moon's

apparent diameter The angular diameter, angular size, apparent diameter, or apparent size is an angular distance describing how large a sphere or circle appears from a given point of view. In the vision sciences, it is called the visual angle, and in optics, it is ...

is smaller than the Sun's, blocking most of the Sun's light and causing the Sun to look like an annulus (ring). An annular eclipse appears as a partial eclipse over a region of the Earth thousands of kilometres wide. Annularity was visible in

South West Africa South West Africa ( af, Suidwes-Afrika; german: Südwestafrika; nl, Zuidwest-Afrika) was a territory under South African administration from 1915 to 1990, after which it became modern-day Namibia. It bordered Angola (Portuguese colony before 1 ...

(today's

Namibia Namibia (, ), officially the Republic of Namibia, is a country in Southern Africa. Its western border is the Atlantic Ocean. It shares land borders with Zambia and Angola to the north, Botswana to the east and South Africa to the south and ea ...

Angola , national_anthem = " Angola Avante"() , image_map = , map_caption = , capital = Luanda , religion = , religion_year = 2020 , religion_ref = , coordina ...

Zambia Zambia (), officially the Republic of Zambia, is a landlocked country at the crossroads of Central, Southern and East Africa, although it is typically referred to as being in Southern Africa at its most central point. Its neighbours are t ...

, southeastern

Zaire Zaire (, ), officially the Republic of Zaire (french: République du Zaïre, link=no, ), was a Congolese state from 1971 to 1997 in Central Africa that was previously and is now again known as the Democratic Republic of the Congo. Zaire was, ...

(today's

Democratic Republic of Congo The Democratic Republic of the Congo (french: République démocratique du Congo (RDC), colloquially "La RDC" ), informally Congo-Kinshasa, DR Congo, the DRC, the DROC, or the Congo, and formerly and also colloquially Zaire, is a country in ...

), northern

Malawi Malawi (; or aláwi Tumbuka: ''Malaŵi''), officially the Republic of Malawi, is a landlocked country in Southeastern Africa that was formerly known as Nyasaland. It is bordered by Zambia to the west, Tanzania to the north and northeas ...

Tanzania Tanzania (; ), officially the United Republic of Tanzania ( sw, Jamhuri ya Muungano wa Tanzania), is a country in East Africa within the African Great Lakes region. It borders Uganda to the north; Kenya to the northeast; Comoro Islands ...

Seychelles Seychelles (, ; ), officially the Republic of Seychelles (french: link=no, République des Seychelles; Creole: ''La Repiblik Sesel''), is an archipelagic state consisting of 115 islands in the Indian Ocean. Its capital and largest city, ...

and the whole British Indian Ocean Territory.

Related eclipses

Eclipses in 1977

* A partial lunar eclipse on Monday, 4 April 1977. * An annular solar eclipse on Monday, 18 April 1977. * A penumbral lunar eclipse on Tuesday, 27 September 1977. * A total solar eclipse on Wednesday, 12 October 1977.

Solar eclipses of 1975–1978

Saros 138

It is a part of Saros cycle 138, repeating every 18 years, 11 days, containing 70 events. The series started with partial solar eclipse on June 6, 1472. It contains annular eclipses from August 31, 1598, through February 18, 2482 with a hybrid eclipse on March 1, 2500. It has total eclipses from March 12, 2518, through April 3, 2554. The series ends at member 70 as a partial eclipse on July 11, 2716. The longest duration of totality will be only 56 seconds on April 3, 2554.

Inex series

Metonic series

Notes

References

1977 4 18 1977 in science 1977 4 18 April 1977 events {{Solar-eclipse-stub