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 the Earth, totally or partially. Such an alignment occurs during an eclipse season, approximately every six month ...

occurred at the Moon's descending node of the orbit on Thursday, April 29, 1976. A

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 Annulus (or anulus) or annular indicates a ring- or donut-shaped area or structure. It may refer to: Human anatomy * ''Anulus fibrosus disci intervertebralis'', spinal structure * Annulus of Zinn, a.k.a. annular tendon or ''anulus tendineus com ...

(ring). An annular eclipse appears as a partial eclipse over a region of the Earth thousands of kilometres wide. Annularity was visible from

North Africa North Africa, or Northern Africa is a region encompassing the northern portion of the African continent. There is no singularly accepted scope for the region, and it is sometimes defined as stretching from the Atlantic shores of Mauritania in ...

Greece Greece,, or , romanized: ', officially the Hellenic Republic, is a country in Southeast Europe. It is situated on the southern tip of the Balkans, and is located at the crossroads of Europe, Asia, and Africa. Greece shares land borders with ...

Turkey Turkey ( tr, Türkiye ), officially the Republic of Türkiye ( tr, Türkiye Cumhuriyeti, links=no ), is a list of transcontinental countries, transcontinental country located mainly on the Anatolia, Anatolian Peninsula in Western Asia, with ...

Middle East The Middle East ( ar, الشرق الأوسط, ISO 233: ) is a geopolitical region commonly encompassing Arabian Peninsula, Arabia (including the Arabian Peninsula and Bahrain), Anatolia, Asia Minor (Asian part of Turkey except Hatay Pro ...

, central

Asia Asia (, ) is one of the world's most notable geographical regions, which is either considered a continent in its own right or a subcontinent of Eurasia, which shares the continental landmass of Afro-Eurasia with Africa. Asia covers an area ...

India India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the so ...

China China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and ...

. 5 of the 14

eight-thousanders The International Mountaineering and Climbing Federation (UIAA) recognises eight-thousanders as the 14 mountains that are more than in height above sea level, and are considered to be sufficiently independent of neighbouring peaks. There is no ...

in Pakistan and China—

Nanga Parbat Nanga Parbat ( ur, ) (; ), known locally as Diamer () which means “king of the mountains”, is the ninth-highest mountain on Earth, its summit at above sea level. Lying immediately southeast of the northernmost bend of the Indus River in ...

, K2,

Broad Peak Broad Peak ( ur, ) is a mountain in the Karakoram on the border of Pakistan and China, the twelfth-highest mountain in the world at above sea level. It was first ascended in June 1957 by Fritz Wintersteller, Marcus Schmuck, Kurt Diemberger, an ...

Gasherbrum II Gasherbrum II ( ur, ; ); surveyed as K4, is the 13th highest mountain in the world at above sea level. It is the third-highest peak of the Gasherbrum massif, and is located in the Karakoram, on the border between Gilgit–Baltistan, Pakistan a ...

and

Gasherbrum I Gasherbrum I ( ur, ; ), surveyed as K5 and also known as Hidden Peak, is the 11th highest mountain in the world at above sea level. It is located in Shigar District in the Gilgit–Baltistan region of Pakistan. Gasherbrum I is part of the Ga ...

, lie in the path of annularity.

Observation

The Institute of Physics and Institute of Mathematics of the

Chinese Academy of Sciences The Chinese Academy of Sciences (CAS); ), known by Academia Sinica in English until the 1980s, is the national academy of the People's Republic of China for natural sciences. It has historical origins in the Academia Sinica during the Republ ...

and the Xinjiang Earthquake Team conducted observations of gravitational effects using gravimeters, inclinometers,

pendulum clock A pendulum clock is a clock that uses a pendulum, a swinging weight, as its timekeeping element. The advantage of a pendulum for timekeeping is that it is a harmonic oscillator: It swings back and forth in a precise time interval dependent on it ...

s and

seismometer A seismometer is an instrument that responds to ground noises and shaking such as caused by earthquakes, volcanic eruptions, and explosions. They are usually combined with a timing device and a recording device to form a seismograph. The outpu ...

s in southwestern

Hotan County Hotan County (also known as Gosthana, Gaustana, Godana, Godaniya, Khotan, Hetian, Hotien) is a county in the southwest of the Xinjiang Uyghur Autonomous Region and is under the administration of the Hotan Prefecture. Almost all the residents of t ...

Hotan Prefecture Hotan PrefectureThe official spelling is "Hotan" according to (also known as Gosthana, Gaustana, Godana, Godaniya, Khotan, Hetian, Hotien) is located in the Tarim Basin region of southwestern Xinjiang, China, bordering the Tibet Autonomous Region ...

Xinjiang Xinjiang, SASM/GNC: ''Xinjang''; zh, c=, p=Xīnjiāng; formerly romanized as Sinkiang (, ), officially the Xinjiang Uygur Autonomous Region (XUAR), is an autonomous region of the People's Republic of China (PRC), located in the northwest ...

near the

Karakoram Pass The Karakoram Pass () is a mountain pass between India and China in the Karakoram Range. It is the highest pass on the ancient caravan route between Leh in Ladakh and Yarkand in the Tarim Basin. 'Karakoram' literally means 'Black Gravel' in ...

at an altitude of . Results showed that the

gravitational acceleration In physics, gravitational acceleration is the acceleration of an object in free fall within a vacuum (and thus without experiencing drag). This is the steady gain in speed caused exclusively by the force of gravitational attraction. All bodies ...

had no obvious effect within the accuracy of the instruments. No inclination was recorded on the photosensitive paper of the inclinometer due to the width of its lines. Three inclinations were pen-recorded, whose time and direction were clearly related to that of the eclipse. Due to the difficult conditions with the high altitude, the observation team was unable to obtain more comparative data.

Related eclipses

Eclipses in 1976

* An annular solar eclipse on Thursday, 29 April 1976. * A partial lunar eclipse on Thursday, 13 May 1976. * A total solar eclipse on Saturday, 23 October 1976. * A penumbral lunar eclipse on Saturday, 6 November 1976.

Solar eclipses of 1975–1978

Saros 128

Metonic series

Notes

References

Solar eclipse of April 29, 1976 in Russia
{{DEFAULTSORT:Solar Eclipse Of April 29, 1976 1976 4 29 1976 in science 1976 4 29 April 1976 events