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 Friday, April 8, 1921, 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 0.9753. 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. The Moon's apparent diameter was near the average diameter because it occurred 6.5 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 1, 1921, at 20:50 UTC) and 8.3 days before

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 April 16, 1921, at 16:10 UTC). Annularity was visible from northern

Scotland Scotland is a Countries of the United Kingdom, country that is part of the United Kingdom. It contains nearly one-third of the United Kingdom's land area, consisting of the northern part of the island of Great Britain and more than 790 adjac ...

, northwestern tip of

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 ...

, and islands in the

Arctic Ocean The Arctic Ocean is the smallest and shallowest of the world's five oceanic divisions. It spans an area of approximately and is the coldest of the world's oceans. The International Hydrographic Organization (IHO) recognizes it as an ocean, ...

Russian SFSR The Russian Soviet Federative Socialist Republic (Russian SFSR or RSFSR), previously known as the Russian Socialist Federative Soviet Republic and the Russian Soviet Republic, and unofficially as Soviet Russia,Declaration of Rights of the labo ...

. A partial eclipse was visible for parts of

North Africa North Africa (sometimes Northern Africa) is a region encompassing the northern portion of the African continent. There is no singularly accepted scope for the region. However, it is sometimes defined as stretching from the Atlantic shores of t ...

Europe Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and Asia to the east ...

Central Asia Central Asia is a region of Asia consisting of Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan, and Uzbekistan. The countries as a group are also colloquially referred to as the "-stans" as all have names ending with the Persian language, Pers ...

, and the

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 1921

* An annular solar eclipse on April 8. * A total lunar eclipse on April 22. * A total solar eclipse on October 1. * A partial lunar eclipse on October 16.

Metonic

* Preceded by: Solar eclipse of June 19, 1917 * Followed by:

Solar eclipse of January 24, 1925 A total solar eclipse occurred at the Moon's descending node of orbit on Saturday, January 24, 1925, with a magnitude of 1.0304. A solar eclipse occurs when the Moon passes between Earth and the Sun, thereby totally or partly obscuring the image o ...

Tzolkinex

* Preceded by: Solar eclipse of February 25, 1914 * Followed by: Solar eclipse of May 19, 1928

Half-Saros

* Preceded by: Lunar eclipse of April 1, 1912 * Followed by: Lunar eclipse of April 13, 1930

Tritos

* Preceded by:

Solar eclipse of May 9, 1910 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 March 7, 1932

Solar Saros 118

* Preceded by: Solar eclipse of March 29, 1903 * Followed 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 ...

Inex

* Preceded by: Solar eclipse of April 26, 1892 * Followed 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 ...

Triad

* Preceded by: Solar eclipse of June 7, 1834 * Followed by: Solar eclipse of February 7, 2008

Solar eclipses of 1921–1924

Saros 118

Metonic series

Tritos series

Inex series

Notes

References

{{commons category, Solar eclipse of 1921 April 8 1921 4 8 1921 4 8 1921 in science April 1921