Tetrad (astronomy)

The frequency of tetrads varies by century with the frequency of total lunar eclipses.

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

List of tetrad events

1949-2000

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

2001-2051

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

References

  1. ↑ Total Penumbral lunar eclipses, Jean Meeus, 1980