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

occurred on September 22, 1968. 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 ...

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 surf ...

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 rad ...

, 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 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 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. Totality was visible from the

Soviet Union The Soviet Union,. officially the Union of Soviet Socialist Republics. (USSR),. was a List of former transcontinental countries#Since 1700, transcontinental country that spanned much of Eurasia from 1922 to 1991. A flagship communist state, ...

(today's

Russia Russia (, , ), or the Russian Federation, is a transcontinental country spanning Eastern Europe and Northern Asia. It is the largest country in the world, with its internationally recognised territory covering , and encompassing one-eigh ...

and

Kazakhstan Kazakhstan, officially the Republic of Kazakhstan, is a transcontinental country located mainly in Central Asia and partly in Eastern Europe. It borders Russia Russia (, , ), or the Russian Federation, is a transcontinental coun ...

) and

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 ...

Northwestern China Northwest China () is a statistical region of China which includes the autonomous regions of Xinjiang and Ningxia and the provinces of Shaanxi, Gansu and Qinghai. It has an area of 3,107,900 km2. The region is characterized by a (semi-)arid con ...

Observation

Soviet Union

A company named Opton proposed to the

Sternberg Astronomical Institute The Sternberg Astronomical Institute (Государственный астрономический институт имени Штернберга in Russian), also known as GAISh (ГАИШ), is a research institution in Moscow, Russia, a divisi ...

to observe this solar eclipse in

Sary Shagan Sary Shagan ( rus, Сары-Шаган; kz, Сарышаған) is an anti-ballistic missile testing range located in Kazakhstan. On 17 August 1956 the Council of Ministers of the Soviet Union authorized plans for an experimental facility for m ...

on the west bank of

Lake Balkhash Lake Balkhash ( kk, Балқаш көлі, ''Balqaş kóli'', ; russian: озеро Балхаш, ozero Balkhash) is a lake in southeastern Kazakhstan, one of the largest lakes in Asia and the 15th largest in the world. It is located in the ea ...

, and also wrote to the Soviet Ministry of Railways for help to get to the destination faster. The observation team obtained

spectrum A spectrum (plural ''spectra'' or ''spectrums'') is a condition that is not limited to a specific set of values but can vary, without gaps, across a continuum. The word was first used scientifically in optics to describe the rainbow of color ...

of the

corona Corona (from the Latin for 'crown') most commonly refers to: * Stellar corona, the outer atmosphere of the Sun or another star * Corona (beer), a Mexican beer * Corona, informal term for the coronavirus SARS-CoV-2, which causes the COVID-19 di ...

. Students also assisted in taking pictures of the corona with MTO-1000 lens. Due to the change of temperature,

snake Snakes are elongated, limbless, carnivorous reptiles of the suborder Serpentes . Like all other squamates, snakes are ectothermic, amniote vertebrates covered in overlapping scales. Many species of snakes have skulls with several more j ...

s also appeared during the observation.

China

This is the first total solar eclipse visible in the country since the founding of the People's Republic of China. It occurred during the

Cultural Revolution The Cultural Revolution, formally known as the Great Proletarian Cultural Revolution, was a sociopolitical movement in the People's Republic of China (PRC) launched by Mao Zedong in 1966, and lasting until his death in 1976. Its stated go ...

, when astronomers including Zhang Yuzhe who organized observations of the total

solar eclipse of June 19, 1936 left, Astronomers in Turkey observing the 1936 eclipse A total solar eclipse occurred at the Moon's descending node on June 19, 1936 (June 18, 1936 east of the International Date Line). A solar eclipse occurs when the Moon passes between Earth a ...

and September 21, 1941 were excluded from key positions. 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 Repub ...

sent a team of 200 including Zhang Kuisan (张魁三), the then deputy director of the Geophysics Bureau to Xinjiang. The observation was code-named "532", named after the time February 1953 when

Mao Zedong Mao Zedong pronounced ; also Romanization of Chinese, romanised traditionally as Mao Tse-tung. (26 December 1893 – 9 September 1976), also known as Chairman Mao, was a Chinese communist revolutionary who was the List of national founde ...

visited the

Purple Mountain Observatory The Purple Mountain Observatory (), also known as Zijinshan Astronomical Observatory is an astronomical observatory located on the Purple Mountain in the east of Nanjing. Description The Purple Mountain Observatory was established in 1934 fu ...

Nanjing Nanjing (; , Mandarin pronunciation: ), Postal Map Romanization, alternately romanized as Nanking, is the capital of Jiangsu Provinces of China, province of the China, People's Republic of China. It is a sub-provincial city, a megacity, and t ...

. The travel to

Ürümqi Ürümqi ( ; also spelled Ürümchi or without Umlaut (diacritic), umlauts), formerly known as Dihua (also spelled Tihwa), is the capital of the Xinjiang, Xinjiang Uyghur Autonomous Region in the far Northwest China, northwest of the Peopl ...

by train first took 3 days, and another 7 days by car to the optical observation site Zhaosu Town (Mongolküre Town),

Zhaosu County Mongolküre County ( mn, ; ug, موڭغۇلكۈرە ناھىيىسى, translit=Mongghulküre; zh, s=蒙古库热县, links=no), also Zhaosu County ( zh, s=昭苏县) as the Chinese romanized name, is a county situated within the Xinjiang Uygh ...

and the radio observation site

Kashgar Kashgar ( ug, قەشقەر, Qeshqer) or Kashi ( zh, c=喀什) is an oasis city in the Tarim Basin region of Southern Xinjiang. It is one of the westernmost cities of China, near the border with Afghanistan, Kyrgyzstan, Tajikistan and Pakistan ...

. Gravity measurements were also conducted in mountain caves. In order to avoid the turmoil of the Cultural Revolution,

Zhou Enlai Zhou Enlai (; 5 March 1898 – 8 January 1976) was a Chinese statesman and military officer who served as the first premier of the People's Republic of China from 1 October 1949 until his death on 8 January 1976. Zhou served under Chairman Ma ...

sent

Liu Xiyao / ( or ) is an East Asian surname. pinyin: in Mandarin Chinese, in Cantonese. It is the family name of the Han dynasty emperors. The character originally meant 'kill', but is now used only as a surname. It is listed 252nd in the classic text ...

to lead the army to the local area and provide the whole team with meals and accommodation. The observation team completed the first monochromatic light observation and high-resolution radio observation of the sun in China. This was also the first time in China that a solar eclipse was observed by plane. Shanghai Scientific and Educational Film Studio also produced a science and education film of the total solar eclipse. The Soviet Union and China were the only two countries the path of this total solar eclipse passed. Due to the

Sino-Soviet split The Sino-Soviet split was the breaking of political relations between the People's Republic of China and the Soviet Union caused by doctrinal divergences that arose from their different interpretations and practical applications of Marxism–Le ...

, the two countries did not conduct any joint observations. About half a year after the eclipse, on January 23, 1969, the People's Daily published an article claiming that the observation of this eclipse "achieved brilliant results", repeatedly criticized the Soviet Union of "obstructing" it, and also mentioned that the Soviet Union "plundered data" of the annular

solar eclipse of April 19, 1958 An annular solar eclipse occurred on April 19, 1958. A solar eclipse occurs when the Moon passes between Earth and the Sun, thereby totally or partly obscuring the image of the Sun for a viewer on Earth. An annular solar eclipse occurs when the Mo ...

Related eclipses

Solar eclipses of 1968–1971

Saros 124

Tritos series

References

External links

Photos from solar eclipse of September 22, 1968 in USSR
(Russian) {{DEFAULTSORT:Solar Eclipse Of September 22, 1968 1968 09 22 1968 in science 1968 09 22 September 1968 events