Solar eclipse of September 22, 1968

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Solar eclipse of September 22, 1968
Map
Type of eclipse
NatureTotal
Gamma0.9451
Magnitude1.0099
Maximum eclipse
Duration40 s (0 min 40 s)
Coordinates56°12′N 64°00′E / 56.2°N 64°E / 56.2; 64
Max. width of band104 km (65 mi)
Times (UTC)
Greatest eclipse11:18:46
References
Saros124 (52 of 73)
Catalog # (SE5000)9439

A total solar eclipse occurred on September 22, 1968. 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. A total solar eclipse occurs when the Moon's apparent diameter 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 (today's Russia and Kazakhstan) and Xinjiang in Northwestern China.

Observation[edit]

Soviet Union[edit]

A company named Opton proposed to the Sternberg Astronomical Institute to observe this solar eclipse in Sary Shagan on the west bank of Lake Balkhash, and also wrote to the Soviet Ministry of Railways for help to get to the destination faster. The observation team obtained spectrum of the corona. Students also assisted in taking pictures of the corona with MTO-1000 lens.[1]

China[edit]

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, when astronomers including Zhang Yuzhe who organized observations of the total solar eclipse of June 19, 1936 and September 21, 1941 were excluded from key positions. The Chinese Academy of Sciences 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 visited the Purple Mountain Observatory in Nanjing. The travel to Ürümqi by train first took 3 days, and another 7 days by car to the optical observation site Zhaosu Town (Mongolküre Town), Zhaosu County and the radio observation site Kashgar. Gravity measurements were also conducted in mountain caves. In order to avoid the turmoil of the Cultural Revolution, Zhou Enlai sent Liu Xiyao 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.[2][3]

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 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.[4][5]

Related eclipses[edit]

Solar eclipses of 1968–1971[edit]

This eclipse is a member of a semester series. An eclipse in a semester series of solar eclipses repeats approximately every 177 days and 4 hours (a semester) at alternating nodes of the Moon's orbit.[6]

Solar eclipse series sets from 1968 to 1971
Ascending node   Descending node
Saros Map Gamma Saros Map Gamma
119
1968 March 28
Partial
−1.03704 124
1968 September 22
Total
0.94507
129
1969 March 18
Annular
−0.27037 134
1969 September 11
Annular
0.22014
139
1970 March 7
Total
0.44728 144
1970 August 31
Annular
−0.53640
149
1971 February 25
Partial
1.11876 154
1971 August 20
Partial
−1.26591
A partial solar eclipse of July 22, 1971 occurs in the next lunar year set.

Saros 124[edit]

Solar saros 124, repeating every about 18 years and 11 days, contains 73 events. The series started with partial solar eclipse on March 6, 1049. It contains total eclipses from June 12, 1211, to September 22, 1968, and a hybrid solar eclipse on October 3, 1986. The series ends at member 73 as a partial eclipse on May 11, 2347. The longest total eclipse occurred on May 3, 1734, at 5 minutes and 46 seconds.[7]

Series members 43–59 occur between 1801 and 2100:
43 44 45

June 16, 1806

June 26, 1824

July 8, 1842
46 47 48

July 18, 1860

July 29, 1878

August 9, 1896
49 50 51

August 21, 1914

August 31, 1932

September 12, 1950
52 53 54

September 22, 1968

October 3, 1986

October 14, 2004
55 56 57

October 25, 2022

November 4, 2040

November 16, 2058
58 59

November 26, 2076

December 7, 2094

Tritos series[edit]

This eclipse is a part of a tritos cycle, repeating at alternating nodes every 135 synodic months (≈ 3986.63 days, or 11 years minus 1 month). Their appearance and longitude are irregular due to a lack of synchronization with the anomalistic month (period of perigee), but groupings of 3 tritos cycles (≈ 33 years minus 3 months) come close (≈ 434.044 anomalistic months), so eclipses are similar in these groupings.

References[edit]

  1. ^ "Полное солнечное затмение 22 сентября 1968 г." Archived from the original on 3 January 2010.
  2. ^ "20世纪中国日全食观测小史". 16 July 2009. Archived from the original on 17 October 2020.
  3. ^ "《新闻调查》 19970314 寻踪日全食". China Network Television. Archived from the original on 10 July 2015.
  4. ^ "用毛泽东思想探索太阳的奥秘——记我国首次大规模日全食综合观测队". People's Daily. 23 January 1969. 一九五八年苏修打着"中苏日环食联合观测"的幌子,来我国掠取日环食资料。观测结束后,把一台破烂不堪的射电望远镜天线留在中国,还美其名曰"帮助中国发展射电天文学"。后来,赫鲁晓夫修正主义集团把这个破烂的射电望远镜天线也要了回去。
  5. ^ "我国大规模日全食综合观测取得辉煌成果". People's Daily. 23 January 1969.
  6. ^ van Gent, R.H. "Solar- and Lunar-Eclipse Predictions from Antiquity to the Present". A Catalogue of Eclipse Cycles. Utrecht University. Retrieved 6 October 2018.
  7. ^ Saros Series Catalog of Solar Eclipses NASA Eclipse Web Site.

External links[edit]