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

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 Tuesday, April 30, 1997, 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 9.9799. 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 6.1 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 April 23, 1997, at 22:20 UTC), the Moon's apparent diameter was smaller. It will be unusual in that while it is a total solar eclipse, it is not a central solar eclipse. A ''non-central'' eclipse is one where the center-line of totality does not intersect the surface of the Earth (when the

gamma Gamma (; uppercase , lowercase ; ) is the third letter of the Greek alphabet. In the system of Greek numerals it has a value of 3. In Ancient Greek, the letter gamma represented a voiced velar stop . In Modern Greek, this letter normally repr ...

is between 9.9972 and 10.0260). Instead, the center line passes just above the Earth's surface. This rare type occurs when totality is only visible at sunset or sunrise in a polar region. Annularity was visible from northern

Soviet Union The Union of Soviet Socialist Republics. (USSR), commonly known as the Soviet Union, was a List of former transcontinental countries#Since 1700, transcontinental country that spanned much of Eurasia from 1922 until Dissolution of the Soviet ...

(today's

Russia Russia, or the Russian Federation, is a country spanning Eastern Europe and North Asia. It is the list of countries and dependencies by area, largest country in the world, and extends across Time in Russia, eleven time zones, sharing Borders ...

) and Bear Island, the southernmost island of

Svalbard Svalbard ( , ), previously known as Spitsbergen or Spitzbergen, is a Norway, Norwegian archipelago that lies at the convergence of the Arctic Ocean with the Atlantic Ocean. North of continental Europe, mainland Europe, it lies about midway be ...

Norway Norway, officially the Kingdom of Norway, is a Nordic countries, Nordic country located on the Scandinavian Peninsula in Northern Europe. The remote Arctic island of Jan Mayen and the archipelago of Svalbard also form part of the Kingdom of ...

. A partial eclipse was visible for parts of

East Africa East Africa, also known as Eastern Africa or the East of Africa, is a region at the eastern edge of the Africa, African continent, distinguished by its unique geographical, historical, and cultural landscape. Defined in varying scopes, the regi ...

, Northeast Pakistan, Territory of Amazon,

Canada Canada is a country in North America. Its Provinces and territories of Canada, ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, making it the world's List of coun ...

, and the

Northwestern United States The Northwestern United States, also known as the American Northwest or simply the Northwest, is an informal geographic region of the United States. The region consistently includes the states of Oregon, Washington, Idaho, Montana and Wyoming ...

. This was the last of 57 umbral eclipses in

Solar Saros 118 Saros cycle series 118 for solar eclipses occurs at the Moon's descending lunar node, node, repeating every 18 years, 11 days, containing 72 eclipses, including 57 umbral eclipses (40 total, 2 hybrid, 15 annular). The first eclipse was on 24 May 80 ...

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 1957

* An annular solar eclipse on April 30. * A total lunar eclipse on May 13. * A total solar eclipse on October 23. * A total lunar eclipse on November 7.

Metonic

* Preceded by: Solar eclipse of July 11, 1953 * Followed by:

Solar eclipse of February 15, 1961 A total solar eclipse occurred at the Moon's descending node of orbit on Wednesday, February 15, 1961, with a magnitude of 1.036. A solar eclipse occurs when the Moon passes between Earth and the Sun, thereby totally or partly obscuring the image ...

Tzolkinex

* Preceded by:

Solar eclipse of March 18, 1950 An annular solar eclipse occurred at the Moon's ascending node of orbit on Saturday, March 18, 1950, with a magnitude of 0.962. 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 June 10, 1964

Half-Saros

* Preceded by: Lunar eclipse of April 23, 1948 * Followed by: Lunar eclipse of May 4, 1966

Tritos

* Preceded by: Solar eclipse of May 30, 1946 * Followed by:

Solar eclipse of March 28, 1968 A partial solar eclipse occurred at the Moon's ascending node of orbit between Thursday, March 28 and Friday, March 29, 1968, with a magnitude of 0.899. A solar eclipse occurs when the Moon passes between Earth and the Sun, thereby totally or part ...

Solar Saros 118

* Preceded by:

Solar eclipse of April 19, 1939 An annular solar eclipse occurred at the Moon's descending node of orbit on Wednesday, April 19, 1939, with a magnitude of 0.9731. A solar eclipse occurs when the Moon passes between Earth and the Sun, thereby totally or partly obscuring the image ...

* Followed by:

Solar eclipse of May 11, 1975 A partial solar eclipse occurred at the Moon's descending node of orbit on Sunday, May 11, 1975, with a magnitude of 0.8636. A solar eclipse occurs when the Moon passes between Earth and the Sun, thereby totally or partly obscuring the image of th ...

Inex

* Preceded by: Solar eclipse of May 19, 1928 * Followed by:

Solar eclipse of April 9, 1986 A partial solar eclipse occurred at the Moon's ascending node of orbit on Wednesday, April 9, 1986, with a magnitude of 0.8236. A solar eclipse occurs when the Moon passes between Earth and the Sun, thereby totally or partly obscuring the image of ...

Triad

* Preceded by: Solar eclipse of June 28, 1870 * Followed by:

Solar eclipse of February 28, 2044 An annular solar eclipse will occur at the Moon's ascending node of orbit on Sunday, February 28, 2044, with a magnitude of 0.96. A solar eclipse occurs when the Moon passes between Earth and the Sun, thereby totally or partly obscuring the image ...

Solar eclipses of 1957–1960

Saros 118

Metonic series

Tritos series

Inex series

Notes

References

{{Solar eclipses 1957 4 30 1957 in science 1957 4 30 April 1957