Tetrad (astronomy)

In astronomy, a tetrad is a set of four total lunar eclipses within two consecutive years. Total Penumbral lunar eclipses, Jean Meeus, 1980

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 1949–2000 SarosDateViewingTypeChartSarosDateViewingTypeChart1949–50Descending node Ascending node1211949 Apr 13Total1261949 Oct 07Total1311950 Apr 02Total1361950 Sep 26Total1967–68Descending node Ascending node1211967 Apr 24Total1261967 Oct 18Total1311968 Apr 13Total1361968 Oct 6Total1985–86Descending node Ascending node1211985 May 04Total1261985 Oct 28Total1311986 Apr 24Total1361986 Oct 17Total

2001–51 SarosDateViewingTypeChartSarosDateViewingTypeChart2003–04Descending node Ascending node1212003 May 16total1262003 Nov 09total1312004 May 04total1362004 Oct 28total2014–15Ascending node Descending node1222014 Apr 15Total1272014 Oct 08Total1322015 Apr 04Total1372015 Sep 28Total2032–33Ascending node Descending node1222032 Apr 25Total1272032 Oct 18Total1322033 Apr 14Total1372033 Oct 08Total2043–44Descending node Ascending node1232043 Mar 25Total1282043 Sep 19Total1332044 Mar 13Total1382044 Sep 07Total2050–51Ascending node Descending node1222050 May 06Total1272050 Oct 30Total1322051 Apr 26Total1372051 Oct 19Total

See also for statistics by century Blood moon prophecy Apocalyptic preaching of John Hagee and Mark Biltz in part based on the observed phenomenon.

References