An annular

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

ascending 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 Thursday, January 4, 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 0.9303. A

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. An annular 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 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. Occurring about 3.75 days after

apogee 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 December 31, 1972, at 21:50 UTC), the Moon's apparent diameter was smaller. Annularity was visible from

Chile Chile, officially the Republic of Chile, is a country in western South America. It is the southernmost country in the world and the closest to Antarctica, stretching along a narrow strip of land between the Andes, Andes Mountains and the Paci ...

and

Argentina Argentina, officially the Argentine Republic, is a country in the southern half of South America. It covers an area of , making it the List of South American countries by area, second-largest country in South America after Brazil, the fourt ...

. A partial eclipse was visible for parts of southern and central

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 ...

Antarctica Antarctica () is Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean (also known as the Antarctic Ocean), it contains the geographic South Pole. ...

West Africa West Africa, also known as Western Africa, is the westernmost region of Africa. The United Nations geoscheme for Africa#Western Africa, United Nations defines Western Africa as the 16 countries of Benin, Burkina Faso, Cape Verde, The Gambia, Gha ...

, and

Southern Africa Southern Africa is the southernmost region of Africa. No definition is agreed upon, but some groupings include the United Nations geoscheme for Africa, United Nations geoscheme, the intergovernmental Southern African Development Community, and ...

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 ...

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 March 18, 1969 * Followed by:

Solar eclipse of October 23, 1976 A total solar eclipse occurred at the Moon's Lunar node, ascending node of orbit on Saturday, October 23, 1976, with a Magnitude of eclipse, magnitude of 1.0572. A solar eclipse occurs when the Moon passes between Earth and the Sun, thereby totall ...

Tzolkinex

* Preceded by: Solar eclipse of November 23, 1965 * Followed by: Solar eclipse of February 16, 1980

Half-Saros

* Preceded by: Lunar eclipse of December 30, 1963 * Followed by: Lunar eclipse of January 9, 1982

Tritos

* Preceded by: Solar eclipse of February 5, 1962 * Followed by: Solar eclipse of December 4, 1983

Solar Saros 131

* Preceded by: Solar eclipse of December 25, 1954 * Followed by: Solar eclipse of January 15, 1991

Inex

* Preceded by:

Solar eclipse of January 25, 1944 A total solar eclipse occurred at the Moon's descending node of orbit on Tuesday, January 25, 1944, with a magnitude of 1.0428. A solar eclipse occurs when the Moon passes between Earth and the Sun, thereby totally or partly obscuring the image of ...

* Followed by:

Solar eclipse of December 14, 2001 An annular solar eclipse occurred at the Moon's Lunar node, descending node of orbit on Friday, December 14, 2001, with a Magnitude of eclipse, magnitude of 0.9681. A solar eclipse occurs when the Moon passes between Earth and the Sun, thereby tot ...

Triad

* Preceded by: Solar eclipse of March 5, 1886 * Followed by: Solar eclipse of November 5, 2059

Solar eclipses of 1971–1974

Saros 131

Metonic series

Tritos series

Inex series

Notess

References

{{Solar eclipses 1973 1 4 1973 in science 1973 1 4 January 1973