Tetrad (astronomy)

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Inex and saros for tetrads between AD 1000 and 2500, showing the tetradia Inex and saros for tetrads between AD 1000 and 2500.png
Inex and saros for tetrads between AD 1000 and 2500, showing the tetradia
Total penumbral eclipse frequency by century.png

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

Contents

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

Saros Date
Viewing
Type
Chart
SarosDate
Viewing
Type
Chart
1949–50
Descending node Ascending node
121 1949 Apr 13
Lunar eclipse from moon-1949Apr13.png
Total
Lunar eclipse chart close-1949Apr13.png
126 1949 Oct 07
Lunar eclipse from moon-1949Oct07.png
Total
Lunar eclipse chart close-1949Oct07.png
131 1950 Apr 02
Lunar eclipse from moon-1950Apr02.png
Total
Lunar eclipse chart close-1950Apr02.png
136 1950 Sep 26
Lunar eclipse from moon-1950Sep26.png
Total
Lunar eclipse chart close-1950Sep26.png
1967–68
Descending node Ascending node
121 1967 Apr 24
Lunar eclipse from moon-1967Apr24.png
Total
Lunar eclipse chart close-1967Apr24.png
126 1967 Oct 18
Lunar eclipse from moon-1967Oct18.png
Total
Lunar eclipse chart close-1967Oct18.png
131 1968 Apr 13
Lunar eclipse from moon-1968Apr13.png
Total
Lunar eclipse chart close-1968Apr13.png
136 1968 Oct 6
Lunar eclipse from moon-1968Oct06.png
Total
Lunar eclipse chart close-1968Oct06.png
1985–86
Descending node Ascending node
121 1985 May 04
Lunar eclipse from moon-1985May04.png
Total
Lunar eclipse chart close-1985May04.png
126 1985 Oct 28
Lunar eclipse from moon-1985Oct28.png
Total
Lunar eclipse chart close-1985Oct28.png
131 1986 Apr 24
Lunar eclipse from moon-1986Apr24.png
Total
Lunar eclipse chart close-1986Apr24.png
136 1986 Oct 17
Lunar eclipse from moon-1986Oct17.png
Total
Lunar eclipse chart close-1986Oct17.png

2001–51

Saros Date
Viewing
Type
Chart
SarosDate
Viewing
Type
Chart
2003–04
Descending node Ascending node
121
Lunar eclipse May 2003-TLR75.jpg
2003 May 16
Lunar eclipse from moon-2003May16.png
total
Lunar eclipse chart close-03may16.png
126
Lunar eclipse November 2003-TLR63.jpg
2003 Nov 09
Lunar eclipse from moon-2003Nov09.png
total
Lunar eclipse chart close-03nov09.png
131
Total lunar eclipse May 4 2004-Jpeter smith.jpg
2004 May 04
Lunar eclipse from moon-2004May04.png
total
Lunar eclipse chart close-04may04.png
136
Oct 28 2004 total lunar eclipse-espenak.png
2004 Oct 28
Lunar eclipse from moon-2004Oct28.png
total
Lunar eclipse chart close-04oct28.png
2014–15
Ascending node Descending node
122
Lunar eclipse April 15 2014 California Alfredo Garcia Jr1.jpg
2014 Apr 15
Lunar eclipse from moon-2014Apr15.png
Total
Lunar eclipse chart close-2014Apr15.png
127
Lunar eclipse October 8 2014 California Alfredo Garcia Jr mideclipse.JPG
2014 Oct 08
Lunar eclipse from moon-2014Oct08.png
Total
Lunar eclipse chart close-2014Oct08.png
132
Lunar eclipse April 4 2015 greatest Alfredo Garcia Jr LA.jpg
2015 Apr 04
Lunar eclipse from moon-2015Apr04.png
Total
Lunar eclipse chart close-2015Apr04.png
137
Lunar eclipse September 27 2015 greatest Alfredo Garcia Jr.jpg
2015 Sep 28
Lunar eclipse from moon-2015Sep28.png
Total
Lunar eclipse chart close-2015Sep28.png
2032–33
Ascending node Descending node
122 2032 Apr 25
Lunar eclipse from moon-2032Apr25.png
Total
Lunar eclipse chart close-2032Apr25.png
127 2032 Oct 18
Lunar eclipse from moon-2032Oct18.png
Total
Lunar eclipse chart close-2032Oct18.png
132 2033 Apr 14
Lunar eclipse from moon-2033Apr14.png
Total
Lunar eclipse chart close-2033Apr14.png
137 2033 Oct 08
Lunar eclipse from moon-2033Oct08.png
Total
Lunar eclipse chart close-2033Oct08.png
2043–44
Descending node Ascending node
123 2043 Mar 25
Lunar eclipse from moon-2043Mar25.png
Total
Lunar eclipse chart close-2043Mar25.png
128 2043 Sep 19
Lunar eclipse from moon-2043Sep19.png
Total
Lunar eclipse chart close-2043Sep19.png
133 2044 Mar 13
Lunar eclipse from moon-2044Mar13.png
Total
Lunar eclipse chart close-2044Mar13.png
138 2044 Sep 07
Lunar eclipse from moon-2044Sep07.png
Total
Lunar eclipse chart close-2044Sep07.png
2050–51
Ascending node Descending node
122 2050 May 06
Lunar eclipse from moon-2050May06.png
Total
Lunar eclipse chart close-2050May06.png
127 2050 Oct 30
Lunar eclipse from moon-2050Oct30.png
Total
Lunar eclipse chart close-2050Oct30.png
132 2051 Apr 26
Lunar eclipse from moon-2051Apr26.png
Total
Lunar eclipse chart close-2051Apr26.png
137 2051 Oct 19
Lunar eclipse from moon-2051Oct19.png
Total
Lunar eclipse chart close-2051Oct19.png

See also

Related Research Articles

There are several lists of lunar eclipses

<span class="mw-page-title-main">March 2006 lunar eclipse</span> Penumbral lunar eclipse 14 March 2006

A penumbral lunar eclipse took place on 14 March 2006, the first of two lunar eclipses in 2006.

<span class="mw-page-title-main">September 1997 lunar eclipse</span> Total lunar eclipse September 16, 1997

A total lunar eclipse took place at the Moon's descending node of the orbit on Tuesday, September 16, 1997, the second of two lunar eclipses in 1997. A shallow total eclipse saw the Moon in relative darkness for 1 hour, 1 minute and 30.8 seconds. The Moon was 19.094% of its diameter into the Earth's umbral shadow, and should have been significantly darkened. The partial eclipse lasted for 3 hours, 16 minutes and 28.2 seconds in total. The penumbral eclipse lasted for 5 hours, 8 minutes and 20.1 seconds. The partial eclipse lasted for 3 hours, 16 minutes and 28.2 seconds. The total eclipse lasted for 1 hour, 1 minute and 30.8 seconds. Maximum eclipse was at 18:46:39.1 UTC. The moon's apparent diameter was extremely large because occurred only 3 hours and 21 minutes past perigee. The Moon was only 356,986 km of the Earth at greatest eclipse.

<span class="mw-page-title-main">April 2014 lunar eclipse</span> Total lunar eclipse in April 2014

A total lunar eclipse took place on 15 April 2014. It was the first of two total lunar eclipses in 2014, and the first in a tetrad. Subsequent eclipses in the tetrad are those of 8 October 2014, 4 April 2015, and 28 September 2015. Occurring 6.7 days after apogee, the Moon's apparent diameter was smaller.

<span class="mw-page-title-main">November 2022 lunar eclipse</span> Total lunar eclipse on 8 November 2022

A total lunar eclipse occurred on Tuesday, 8 November 2022. The southern limb of the Moon passed through the center of the Earth's shadow. It surpassed the previous eclipse as the longest total lunar eclipse visible from nearly all of North America since 17 August 1989, and until 26 June 2029. Occurring only 5.8 days before apogee, the Moon's apparent diameter was smaller. The next total lunar eclipse will take place on 14 March 2025. A lunar occultation of Uranus happened during the eclipse. It was the first total lunar eclipse on Election Day in US history. This event was referred in media coverage as a "beaver blood moon".

<span class="mw-page-title-main">October 2051 lunar eclipse</span> Central lunar eclipse

A total lunar eclipse will take place on October 19, 2051. The northern limb of the Moon will pass through the center of the Earth's shadow.

A penumbral lunar eclipse took place on Thursday, March 3, 1988, the first of two lunar eclipses in 1988, the second being on August 27, 1988. Earlier sources compute this as a 0.3% partial eclipse lasting under 14 minutes, and newest calculations list it as a penumbral eclipse that never enters the umbral shadow. In a rare total penumbral eclipse, the entire Moon was partially shaded by the Earth, and the shading across the Moon should have been quite visible at maximum eclipse. The penumbral phase lasted for 4 hours, 53 minutes and 50.6 seconds in all, though for most of it, the eclipse was extremely difficult or impossible to see. The Moon was 2.2 days after apogee, making it 6.1% smaller than average.

<span class="mw-page-title-main">June 1991 lunar eclipse</span> Penumbral lunar eclipse June 27, 1991

A penumbral lunar eclipse took place on Thursday, June 27, 1991, the second of four lunar eclipses in 1991. The moon entered the Earth's penumbra for about 3 hours, and was difficult to see. This lunar eclipse is the predecessor of the Solar eclipse of July 11, 1991.

A penumbral lunar eclipse took place on Thursday, November 8, 1984, the last of three lunar eclipses in 1984. This subtle penumbral eclipse may have been visible to a skilled observer at maximum eclipse. 90% of the Moon's disc was partially shaded by the Earth, which caused a gentle shadow gradient across its disc at maximum; the eclipse as a whole lasted 4 hours and 28 minutes.

A penumbral lunar eclipse took place on Tuesday, May 15, 1984, the first of three lunar eclipses in 1984. This was a deep penumbral eclipse, with the southern limb of the Moon close to the Earth's shadow.

<span class="mw-page-title-main">November 2021 lunar eclipse</span> Partial lunar eclipse of 19 November 2021

A partial lunar eclipse occurred on 19 November 2021. The eclipse occurred towards a micromoon. This was the longest partial lunar eclipse since 18 February 1440, and the longest until 8 February, 2669; however, many eclipses, including the November 2022 lunar eclipse, have a longer period of umbral contact at next to 3 hours 40 minutes. It was often referred to as a "Beaver Blood Moon" although not technically fulfilling the criteria for a true blood moon (totality).

<span class="mw-page-title-main">August 2026 lunar eclipse</span>

A partial lunar eclipse will take place on Friday 28 August 2026. The moon will be almost be inside the umbra, but not quite be contained within the umbral shadow at greatest eclipse.

<span class="mw-page-title-main">August 2027 lunar eclipse</span> Penumbral

A penumbral lunar eclipse will take place on Tuesday, August 17, 2027. It will cause a subtle dimming as 54.56% of the Moon will cross within Earth's penumbral shadow.

<span class="mw-page-title-main">April 1967 lunar eclipse</span> Total lunar eclipse April 24, 1967

A total lunar eclipse took place on Monday, April 24, 1967, the first of two total lunar eclipses in 1967, the second being on October 18, 1967.

<span class="mw-page-title-main">January 1963 lunar eclipse</span> Penumbral lunar eclipse January 9, 1963

A penumbral lunar eclipse took place on Wednesday, January 9, 1963, the first of three lunar eclipses in 1963.

<span class="mw-page-title-main">Total penumbral lunar eclipse</span> Total penumbral lunar eclipse

A total penumbral lunar eclipse is a lunar eclipse that occurs when the Moon becomes completely immersed in the penumbral cone of the Earth without touching the umbra.

<span class="mw-page-title-main">March 2043 lunar eclipse</span> Astronomical event

A total lunar eclipse will take place on March 25, 2043.

<span class="mw-page-title-main">May 2050 lunar eclipse</span>

A total lunar eclipse will take place on May 6, 2050.

<span class="mw-page-title-main">April 2051 lunar eclipse</span>

A total lunar eclipse will take place on April 26, 2051.

<span class="mw-page-title-main">October 2050 lunar eclipse</span>

A total lunar eclipse will take place on October 30, 2050.

References