A total

solar eclipse A solar eclipse occurs when the Moon passes between Earth and the Sun, thereby obscuring the view of the Sun from a small part of Earth, totally or partially. Such an alignment occurs approximately every six months, during the eclipse season i ...

occurred at the Moon's

descending node An orbital node is either of the two points where an orbit intersects a plane of reference to which it is inclined. A non-inclined orbit, which is contained in the reference plane, has no nodes. Planes of reference Common planes of referenc ...

of orbit on Saturday, June 30, 1973, with a

magnitude Magnitude may refer to: Mathematics *Euclidean vector, a quantity defined by both its magnitude and its direction *Magnitude (mathematics), the relative size of an object *Norm (mathematics), a term for the size or length of a vector *Order of ...

of 1.0792. A solar eclipse occurs when the

Moon The Moon is Earth's only natural satellite. It Orbit of the Moon, orbits around Earth at Lunar distance, an average distance of (; about 30 times Earth diameter, Earth's diameter). The Moon rotation, rotates, with a rotation period (lunar ...

passes between

Earth Earth is the third planet from the Sun and the only astronomical object known to Planetary habitability, harbor life. This is enabled by Earth being an ocean world, the only one in the Solar System sustaining liquid surface water. Almost all ...

and the

Sun The Sun is the star at the centre of the Solar System. It is a massive, nearly perfect sphere of hot plasma, heated to incandescence by nuclear fusion reactions in its core, radiating the energy from its surface mainly as visible light a ...

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

apparent diameter The angular diameter, angular size, apparent diameter, or apparent size is an angular separation (in units of angle) describing how large a sphere or circle appears from a given point of view. In the vision sciences, it is called the '' visual ...

is larger than the Sun's, blocking all direct sunlight, turning day into darkness. Totality occurs in a narrow path across Earth's surface, with the partial solar eclipse visible over a surrounding region thousands of kilometres wide. Occurring about 11 hours after

perigee An apsis (; ) is the farthest or nearest point in the orbit of a planetary body about its primary body. The line of apsides (also called apse line, or major axis of the orbit) is the line connecting the two extreme values. Apsides perta ...

(on June 30, 1973, at 0:50 UTC), the Moon's apparent diameter was larger. With a maximum eclipse of 7 minutes and 3.55 seconds, this was the last total solar eclipse that exceeds 7 minutes in this series. There will not be a longer total solar eclipse until June 25, 2150. The greatest eclipse occurred in the

Agadez Agadez ( Air Tamajeq: ⴰⴶⴰⴷⴰⵣ, ''Agadaz''), formerly spelled Agadès, is the fifth largest city in Niger, with a population of 110,497 based on the 2012 census. The capital of the eponymous Agadez Region, the city lies in the Sahara ...

area in the northwest of Niger not far from Algeria inside the Sahara Desert somewhat 40 km east of the small mountain of Ebenenanoua at 18.8 N and 5.6 E and occurred at 11:38 UTC. The umbral portion of the path started near the border of

Guyana Guyana, officially the Co-operative Republic of Guyana, is a country on the northern coast of South America, part of the historic British West Indies. entry "Guyana" Georgetown, Guyana, Georgetown is the capital of Guyana and is also the co ...

and the

Brazil Brazil, officially the Federative Republic of Brazil, is the largest country in South America. It is the world's List of countries and dependencies by area, fifth-largest country by area and the List of countries and dependencies by population ...

ian state

Roraima Roraima ( ) is one of the 26 states of Brazil. Located in the country's North Region, it is the northernmost and most geographically and logistically isolated state in Brazil. It is bordered by the state of Pará to the southeast, Amazonas t ...

, passed northern Dutch Guiana (today's

Suriname Suriname, officially the Republic of Suriname, is a country in northern South America, also considered as part of the Caribbean and the West Indies. It is a developing country with a Human Development Index, high level of human development; i ...

), headed into the Atlantic, included one of the

Portuguese Cape Verde Cape Verde was a colony of the Portuguese Empire from the initial settlement of the Cape Verde Islands in 1462 until the independence of Cape Verde in 1975. History 15th century The islands of Cape Verde were discovered in 1460-62 by Pri ...

(today's

Cape Verde Cape Verde or Cabo Verde, officially the Republic of Cabo Verde, is an island country and archipelagic state of West Africa in the central Atlantic Ocean, consisting of ten volcanic islands with a combined land area of about . These islands ...

) Islands, which was Santo Antão,

Nouadhibou Nouadhibou (; , ), formerly named Port-Étienne, is the second largest city in Mauritania and serves as a major commercial center. The city has about 173,000 inhabitants. It is situated on a 65-kilometre peninsula or headland called Ras Nouadhibou ...

and

Nouakchott Nouakchott ( ) is the capital and largest city of Mauritania. Located in the southwestern part of the country, it is one of the largest cities in the Sahara. The city also serves as the administrative and economic center of Mauritania. Once a ...

and other parts of Central

Mauritania Mauritania, officially the Islamic Republic of Mauritania, is a sovereign country in Maghreb, Northwest Africa. It is bordered by the Atlantic Ocean to the west, Western Sahara to Mauritania–Western Sahara border, the north and northwest, ...

, northern

Mali Mali, officially the Republic of Mali, is a landlocked country in West Africa. It is the List of African countries by area, eighth-largest country in Africa, with an area of over . The country is bordered to the north by Algeria, to the east b ...

, the southernmost of

Algeria Algeria, officially the People's Democratic Republic of Algeria, is a country in the Maghreb region of North Africa. It is bordered to Algeria–Tunisia border, the northeast by Tunisia; to Algeria–Libya border, the east by Libya; to Alger ...

, the middle and southeastern

Niger Niger, officially the Republic of the Niger, is a landlocked country in West Africa. It is a unitary state Geography of Niger#Political geography, bordered by Libya to the Libya–Niger border, north-east, Chad to the Chad–Niger border, east ...

, the middle of

Chad Chad, officially the Republic of Chad, is a landlocked country at the crossroads of North Africa, North and Central Africa. It is bordered by Libya to Chad–Libya border, the north, Sudan to Chad–Sudan border, the east, the Central Afric ...

, the

Sudan Sudan, officially the Republic of the Sudan, is a country in Northeast Africa. It borders the Central African Republic to the southwest, Chad to the west, Libya to the northwest, Egypt to the north, the Red Sea to the east, Eritrea and Ethiopi ...

including

Darfur Darfur ( ; ) is a region of western Sudan. ''Dār'' is an Arabic word meaning "home f – the region was named Dardaju () while ruled by the Daju, who migrated from Meroë , and it was renamed Dartunjur () when the Tunjur ruled the area. ...

and parts that are now in the

South Sudan South Sudan (), officially the Republic of South Sudan, is a landlocked country in East Africa. It is bordered on the north by Sudan; on the east by Ethiopia; on the south by the Democratic Republic of the Congo, Uganda and Kenya; and on the ...

including Kodok, a part of the northernmost

Uganda Uganda, officially the Republic of Uganda, is a landlocked country in East Africa. It is bordered to the east by Kenya, to the north by South Sudan, to the west by the Democratic Republic of the Congo, to the south-west by Rwanda, and to the ...

, a part of northern

Kenya Kenya, officially the Republic of Kenya, is a country located in East Africa. With an estimated population of more than 52.4 million as of mid-2024, Kenya is the 27th-most-populous country in the world and the 7th most populous in Africa. ...

, the southernmost of

Somalia Somalia, officially the Federal Republic of Somalia, is the easternmost country in continental Africa. The country is located in the Horn of Africa and is bordered by Ethiopia to the west, Djibouti to the northwest, Kenya to the southwest, th ...

, and the

Alphonse Group The Alphonse Group belong to the Outer Islands of the Seychelles, lying in the southwest of the island nation, southwest the capital, Victoria, on Mahé Island. The closest island is Desnœufs Island of the Amirante Islands, further north. ...

of British

Seychelles Seychelles (, ; ), officially the Republic of Seychelles (; Seychellois Creole: ), is an island country and archipelagic state consisting of 155 islands (as per the Constitution) in the Indian Ocean. Its capital and largest city, Victoria, ...

(today's Seychelles). A partial eclipse was visible for parts of eastern

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a considerably smaller portion in the Northern Hemisphere. It can also be described as the southern Subregion#Americas, subregion o ...

Africa Africa is the world's second-largest and second-most populous continent after Asia. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 20% of Earth's land area and 6% of its total surfac ...

Southern Europe Southern Europe is also known as Mediterranean Europe, as its geography is marked by the Mediterranean Sea. Definitions of southern Europe include some or all of these countries and regions: Albania, Andorra, Bosnia and Herzegovina, Bulgaria, C ...

, and the

Middle East The Middle East (term originally coined in English language) is a geopolitical region encompassing the Arabian Peninsula, the Levant, Turkey, Egypt, Iran, and Iraq. The term came into widespread usage by the United Kingdom and western Eur ...

Observations

This eclipse was observed by a group of scientists, which included Donald Liebenberg, from the

Los Alamos National Laboratory Los Alamos National Laboratory (often shortened as Los Alamos and LANL) is one of the sixteen research and development Laboratory, laboratories of the United States Department of Energy National Laboratories, United States Department of Energy ...

. They used two airplanes to extend the apparent time of totality by flying along the eclipse path in the same direction as the Moon's shadow as it passed over

. One of the planes was a prototype (c/n 001) of what was later to become the

Concorde Concorde () is a retired Anglo-French supersonic airliner jointly developed and manufactured by Sud Aviation and the British Aircraft Corporation (BAC). Studies started in 1954, and France and the United Kingdom signed a treaty establishin ...

, which has a top speed of almost (Mach 2). This enabled scientists from Los Alamos, the Paris Observatory, the Kitt Peak National Observatory, Queen Mary University of London, the University of Aberdeen and CNRS to extend totality to more than 74 minutes; nearly 10 times longer than is possible when viewing a total solar eclipse from a stationary location. The Concorde was specially modified with rooftop portholes for the mission, and is currently on display with the Solar Eclipse mission livery at Musée de l’air et de l’espace. The data gathered resulted in three papers published in ''

Nature Nature is an inherent character or constitution, particularly of the Ecosphere (planetary), ecosphere or the universe as a whole. In this general sense nature refers to the Scientific law, laws, elements and phenomenon, phenomena of the physic ...

'' and a book. The eclipse was also observed by a charter flight from Mount San Antonio College in Southern California. The DC-8 with 150 passengers intercepted the eclipse at just off the east coast of Africa and tracked the eclipse for three minutes. The passengers rotated seats every 20 seconds so that each passenger had three 20 second opportunities at the window to observe and take pictures. A separate observation opportunity was provided on a specialized commercial cruise by the S.S. ''Canberra'', which traveled from New York City to the Canary Islands and Dakar, Senegal, observing 5 minutes and 44 seconds of totality out in the Atlantic between those two stops in Africa. That cruise's passengers included notables in the scientific community such as

Neil Armstrong Neil Alden Armstrong (August 5, 1930 – August 25, 2012) was an American astronaut and aerospace engineering, aeronautical engineer who, in 1969, became the Apollo 11#Lunar surface operations, first person to walk on the Moon. He was al ...

Scott Carpenter Malcolm Scott Carpenter (May 1, 1925 – October 10, 2013) was an American naval officer and aviator, test pilot, aeronautical engineer, astronaut, and aquanaut. He was one of the Mercury Seven astronauts selected for NASA's Project Mercury ...

Isaac Asimov Isaac Asimov ( ; – April 6, 1992) was an Russian-born American writer and professor of biochemistry at Boston University. During his lifetime, Asimov was considered one of the "Big Three" science fiction writers, along with Robert A. H ...

, Walter Sullivan, and the then 15-years old

Neil deGrasse Tyson Neil deGrasse Tyson ( or ; born October 5, 1958) is an American astrophysics, astrophysicist, author, and science communication, science communicator. Tyson studied at Harvard University, the University of Texas at Austin, and Columbia Univ ...

Eclipse details

Shown below are two tables displaying details about this particular solar eclipse. The first table outlines times at which the moon's penumbra or umbra attains the specific parameter, and the second table describes various other parameters pertaining to this eclipse.

Eclipse season

This eclipse is part of an

eclipse season An eclipse season is a period, roughly every six months, when eclipses occur. Eclipse seasons are the result of the axial parallelism of the Orbit of the Moon, Moon's orbital plane (orbital inclination, tilted five degrees to the ecliptic, Earth ...

, a period, roughly every six months, when eclipses occur. Only two (or occasionally three) eclipse seasons occur each year, and each season lasts about 35 days and repeats just short of six months (173 days) later; thus two full eclipse seasons always occur each year. Either two or three eclipses happen each eclipse season. In the sequence below, each eclipse is separated by a

fortnight A fortnight is a unit of time equal to 14 days (two weeks). The word derives from the Old English term , meaning "" (or "fourteen days", since the Anglo-Saxons counted by nights). Astronomy and tides In astronomy, a ''lunar fortnight'' is hal ...

. The first and last eclipse in this sequence is separated by one

synodic month In lunar calendars, a lunar month is the time between two successive Syzygy (astronomy), syzygies of the same type: new moons or full moons. The precise definition varies, especially for the beginning of the month. Variations In Shona people, S ...

Related eclipses

Eclipses in 1973

* An annular solar eclipse on January 4. * A penumbral lunar eclipse on January 18. * A penumbral lunar eclipse on June 15. * A total solar eclipse on June 30. * A penumbral lunar eclipse on July 15. * A partial lunar eclipse on December 10. * An annular solar eclipse on December 24.

Metonic

* Preceded by: Solar eclipse of September 11, 1969 * Followed by: Solar eclipse of April 18, 1977

Tzolkinex

* Preceded by: Solar eclipse of May 20, 1966 * Followed by: Solar eclipse of August 10, 1980

Half-Saros

* Preceded by: Lunar eclipse of June 25, 1964 * Followed by: Lunar eclipse of July 6, 1982

Tritos

* Preceded by:

Solar eclipse of July 31, 1962 Solar may refer to: Astronomy * Of or relating to the Sun ** Solar telescope, a special purpose telescope used to observe the Sun ** A device that utilizes solar energy (e.g. "solar panels") ** Solar calendar, a calendar whose dates indicate t ...

* Followed by: Solar eclipse of May 30, 1984

Solar Saros 136

* Preceded by: Solar eclipse of June 20, 1955 * Followed by: Solar eclipse of July 11, 1991

Inex

* Preceded by: Solar eclipse of July 20, 1944 * Followed by: Solar eclipse of June 10, 2002

Triad

* Preceded by: Solar eclipse of August 29, 1886 * Followed by: Solar eclipse of April 30, 2060

Solar eclipses of 1971–1974

Saros 136

Metonic series

Tritos series

Inex series

Notes

References

Foto Solar eclipse of June 30, 1973

Foto Solar eclipse of June 30, 1995 from Russia expedition

{{DEFAULTSORT:Solar Eclipse Of June 30, 1973 Total solar eclipses, 1973 06 30 1973 in science 1973 06 30 June 1973