Tetrad (astronomy)

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Inex and saros for tetrads between AD 1000 and 2500, showing the tetradia

In astronomy, a tetrad is a set of four total lunar eclipses within two consecutive years.[1]

The frequency of tetrads varies by century with the frequency of total lunar eclipses. This repeating cycle is called a tetradia. See Eclipse cycle for more information.

List of tetrad events[edit]

1949–2000[edit]

Saros Date
Viewing
Type
Chart
Saros Date
Viewing
Type
Chart
1949–50
Descending node   Ascending node
121 1949 Apr 13
Total
126 1949 Oct 07
Total
131 1950 Apr 02
Total
136 1950 Sep 26
Total
1967–68
Descending node   Ascending node
121 1967 Apr 24
Total
126 1967 Oct 18
Total
131 1968 Apr 13
Total
136 1968 Oct 6
Total
1985–86
Descending node   Ascending node
121 1985 May 04
Total
126 1985 Oct 28
Total
131 1986 Apr 24
Total
136 1986 Oct 17
Total

2001–51[edit]

Saros Date
Viewing
Type
Chart
Saros Date
Viewing
Type
Chart
2003–04
Descending node   Ascending node
121
2003 May 16
total
126
2003 Nov 09
total
131
2004 May 04
total
136
2004 Oct 28
total
2014–15
Ascending node   Descending node
122
2014 Apr 15
Total
127
2014 Oct 08
Total
132
2015 Apr 04
Total
137
2015 Sep 28
Total
2032–33
Ascending node   Descending node
122 2032 Apr 25
Total
127 2032 Oct 18
Total
132 2033 Apr 14
Total
137 2033 Oct 08
Total
2043–44
Descending node   Ascending node
123 2043 Mar 25
Total
128 2043 Sep 19
Total
133 2044 Mar 13
Total
138 2044 Sep 07
Total
2050–51
Ascending node   Descending node
122 2050 May 06
Total
127 2050 Oct 30
Total
132 2051 Apr 26
Total
137 2051 Oct 19
Total

See also[edit]

References[edit]