$$\def\|{&}\DeclareMathOperator{\D}{\bigtriangleup\!} \DeclareMathOperator{\d}{\text{d}\!}$$

The diagram below is explained further on the page for the year 2000.

For an explanation of the above pictures, see the page for the year 2000.

The last table on this page lists a number of noteworthy planetary phenomena during the listed year. The first column ("date") gives the date and hour, in the form year-month-dayThour in the Gregorian calendar, in Universal Time (UT). The second column ("pl") identifies the planet that shows the phenomenon:

pl Planet
Me Mercury
Ve Venus
Ma Mars
Ju Jupiter
Sa Saturn
Ur Uranus
Ne Neptune
Lu Moon

The third column ("*") provides the type of the phenomenon. The fourth column ("AU") shows the value (distance) in Astronomical Units, if applicable. The fifth column ("deg") gives the value of a relevant angle (declination $$δ$$, elongation $$E$$, conjunction spread $$σ$$, or ecliptic longitude $$λ$$) in degrees. Which angle it is for each phenomenon is shown below in column "?". Declinations and ecliptical longitudes are measured relative to the equinox of the date.

 ?
Explanation
p perigee
a apogee
+dδgreatest northern declination
−dδgreatest southern declination
cλconjunction (with the Sun)
oλopposition (relative to the Sun)
eEgreatest elongation
xaλpassage through the ascending node (zero ecliptical latitude)
xdλpassage through the descending node (zero ecliptical latitude)
bσleast conjunction spread (Mercury - Saturn)
Bσleast conjunction spread (Mercury - Neptune)
sσgreatest conjunction spread (Mercury - Saturn)
Sσgreatest conjunction spread (Mercury - Neptune)
Vλbegin eastward (prograde) acceleration
Pgλstationary point: begin eastward (prograde) motion
vλbegin westward (retrograde) acceleration
Rgλstationary point: begin westward (retrograde) motion

The calculations for the planets are based on the VSOP87 model (type A) of Laskar, and the calculations for the Moon are based on the most detailed model from [Meeus]. One position per day was calculated for each celestial object. The hour of the day for each phenomenon was determined by interpolation.

date pl *  AU deg
1991-01-01T00 Ma Pg +57.75
1991-01-01T11 Lu xd +118.02
1991-01-03T06 Me Pg +263.70
1991-01-03T09
**
s  +184.96
1991-01-04T14 Ne a  31.19
1991-01-04T15 Ne c  +284.28
1991-01-04T22 Ne v  +284.29
1991-01-11T21 Lu V  +252.39
1991-01-11T23 Lu a 0.002714
1991-01-12T13 Lu −d −26.32
1991-01-14T01 Me e  −23.64
1991-01-15T11 Lu c  +295.31
1991-01-15T14
**
B  +127.78
1991-01-15T17 Lu xa +298.02
1991-01-17T14 Sa a  10.97
1991-01-17T17 Sa v  +297.70
1991-01-17T19 Sa c  +297.71
1991-01-24T01 Me xa +282.26
1991-01-24T20 Me −d −22.88
1991-01-26T09 Lu +d +26.32
1991-01-27T20 Ju p  4.306
1991-01-27T20 Lu p 0.002420
1991-01-27T20 Lu v  +102.03
1991-01-28T07 Ju V  +128.61
1991-01-28T12 Ju o  +128.58
1991-01-28T22 Lu xd +118.07
1991-01-29T16
**
S  +182.13
1991-01-29T18 Lu o  +129.82
1991-02-08T16 Lu V  +258.10
1991-02-08T16 Lu a 0.002708
1991-02-08T21 Lu −d −26.29
1991-02-12T00 Lu xa +297.98
1991-02-13T12
**
B  +131.36
1991-02-14T05 Lu c  +325.53
1991-02-22T04 Me a  1.388
1991-02-22T16 Lu +d +26.23
1991-02-24T12 Lu p 0.002457
1991-02-24T18 Lu v  +109.93
1991-02-25T07 Lu xd +117.55
1991-02-28T03
**
S  +192.77
1991-02-28T06 Lu o  +159.66
1991-03-02T00 Me o  +341.76
1991-03-08T05 Lu −d −26.14
1991-03-08T13 Lu a 0.002702
1991-03-08T16 Lu V  +266.05
1991-03-09T05 Me v  +355.69
1991-03-11T06 Lu xa +296.76
1991-03-14T17 Me xd +6.31
1991-03-14T17
**
B  +144.96
1991-03-15T20 Lu c  +232.90
1991-03-17T21 Ve xd +29.37
1991-03-20T15 Lu v  +62.54
1991-03-21T17 Lu p 0.002473
1991-03-21T22 Lu +d +26.02
1991-03-24T10 Lu xd +115.61
1991-03-26T21 Me e  +18.61
1991-03-29T04 Ju +d +20.12
1991-03-29T19 Lu o  +189.12
1991-03-29T19 Ma +d +25.37
1991-03-29T20
**
S  +222.84
1991-03-30T00 Ju Pg +123.54
1991-04-02T06
**
b  +125.75
1991-04-04T06 Me Rg +29.02
1991-04-04T09 Me +d +14.17
1991-04-04T13 Lu −d −25.89
1991-04-05T08 Lu a 0.002703
1991-04-05T16 Lu V  +273.87
1991-04-07T09 Lu xa +294.10
1991-04-12T19 Ur +d −23.08
1991-04-12T20
**
B  +163.46
1991-04-14T07 Lu c  +24.34
1991-04-14T08 Me c  +24.39
1991-04-15T04 Me V  +23.79
1991-04-16T17 Lu v  +59.28
1991-04-17T05 Lu p 0.002443
1991-04-17T15 Me p  0.5736
1991-04-17T18 Ur Rg +283.81
1991-04-18T04 Lu +d +25.78
1991-04-18T06 Ne Rg +286.76
1991-04-20T10 Lu xd +112.75
1991-04-22T01 Me xa +19.38
1991-04-22T08 Ne +d −21.59
1991-04-26T14
**
S  +264.61
1991-04-27T21 Me Pg +17.98
1991-04-28T09 Lu o  +218.06
1991-05-01T20 Lu −d −25.69
1991-05-02T16 Me −d +5.21
1991-05-03T02 Lu a 0.002708
1991-05-03T13 Lu V  +280.51
1991-05-04T11 Lu xa +291.20
1991-05-10T02
**
s  +138.78
1991-05-10T09
**
B  +187.11
1991-05-10T22 Ve +d +25.92
1991-05-12T02 Sa +d −18.90
1991-05-12T04 Me e  −26.01
1991-05-13T16 Lu c  +52.90
1991-05-14T21 Lu v  +70.91
1991-05-15T04 Lu p 0.002411
1991-05-15T12 Lu +d +25.64
1991-05-16T14 Sa Rg +306.84
1991-05-17T13 Lu xd +110.25
1991-05-26T21
**
S  +286.81
1991-05-27T23 Lu o  +246.63
1991-05-29T02 Lu −d −25.60
1991-05-30T14 Lu a 0.002713
1991-05-31T02 Lu V  +283.82
1991-05-31T14 Lu xa +289.35
1991-06-10T17 Me xd +72.49
1991-06-11T21 Lu +d +25.60
1991-06-12T00 Lu c  +81.03
1991-06-12T08 Lu v  +86.24
1991-06-12T12 Lu p 0.002392
1991-06-13T15 Ve e  +45.35
1991-06-13T20 Lu xd +109.06
1991-06-16T04 Me v  +84.40
1991-06-17T00 Me o  +86.20
1991-06-17T04 Me a  1.324
1991-06-19T03
**
B  +190.03
1991-06-21T09 Me +d +24.87
1991-06-25T07 Lu −d −25.61
1991-06-26T15 Lu o  +274.99
1991-06-26T19 Lu a 0.002716
1991-06-27T01 Lu V  +280.06
1991-06-27T19 Lu xa +288.92
1991-07-03T03
**
S  +246.78
1991-07-03T05 Ur p  18.46
1991-07-03T18 Ur o  +281.82
1991-07-04T00 Ur V  +281.81
1991-07-07T10 Ve xa +147.87
1991-07-07T12 Ne o  +285.37
1991-07-07T13 Ne p  29.18
1991-07-07T18 Ne V  +285.36
1991-07-09T08 Lu +d +25.63
1991-07-10T21 Lu v  +103.06
1991-07-10T22 Lu p 0.002390
1991-07-11T07 Lu xd +108.92
1991-07-11T07 Lu c  +108.98
1991-07-18T07
**
B  +151.32
1991-07-19T00 Me xa +142.66
1991-07-22T13 Lu −d −25.62
1991-07-23T19 Lu V  +274.02
1991-07-23T23 Lu a 0.002714
1991-07-24T10 Me e  +27.01
1991-07-25T01 Lu xa +288.97
1991-07-26T06 Lu o  +303.25
1991-07-26T12 Sa o  +303.50
1991-07-26T13 Sa V  +303.50
1991-07-26T16 Sa p  8.947
1991-07-31T22 Ve Rg +157.32
1991-08-01T07
**
S  +199.63
1991-08-05T17 Lu +d +25.59
1991-08-07T11 Me Rg +155.90
1991-08-07T17 Lu xd +108.83
1991-08-08T06 Lu p 0.002407
1991-08-08T10 Lu v  +119.40
1991-08-09T14 Lu c  +137.01
1991-08-10T07
**
b  +109.83
1991-08-11T03 Me −d +5.46
1991-08-13T13 Ve −d +3.36
1991-08-14T06
**
B  +138.44
1991-08-16T09 Ju v  +144.29
1991-08-17T10 Ju c  +144.52
1991-08-17T20 Ju a  6.366
1991-08-18T04 Me p  0.6109
1991-08-18T20 Lu −d −25.54
1991-08-20T05 Lu V  +275.68
1991-08-20T11 Lu a 0.002708
1991-08-20T12 Me V  +149.01
1991-08-21T07 Lu xa +288.45
1991-08-21T08 Me c  +148.29
1991-08-22T08 Ve c  +149.24
1991-08-22T12 Ve V  +149.12
1991-08-22T16 Ve p  0.2875
1991-08-24T21 Lu o  +331.68
1991-08-28T22
**
S  +200.09
1991-08-31T02 Me Pg +143.05
1991-09-02T00 Lu +d +25.44
1991-09-03T23 Lu xd +107.66
1991-09-04T19
**
s  +114.03
1991-09-05T07 Lu p 0.002438
1991-09-05T13 Me +d +12.87
1991-09-05T17 Lu v  +132.77
1991-09-06T16 Me xd +146.08
1991-09-07T05 Me e  −18.00
1991-09-07T23 Lu c  +165.29
1991-09-11T18
**
B  +137.13
1991-09-12T20 Ve Pg +141.00
1991-09-15T04 Lu −d −25.34
1991-09-15T19 Ur −d −23.45
1991-09-17T00 Lu V  +281.37
1991-09-17T03 Lu a 0.002703
1991-09-17T10 Lu xa +286.57
1991-09-18T17 Ur Pg +279.83
1991-09-23T10 Lu o  +20.10
1991-09-23T14 Me v  +172.61
1991-09-25T14 Ne Pg +283.98
1991-09-25T15
**
S  +177.88
1991-09-27T15 Ve +d +9.16
1991-09-29T06 Lu +d +25.21
1991-10-01T01 Lu xd +105.14
1991-10-02T05 Lu p 0.002469
1991-10-02T23 Me o  +189.64
1991-10-03T01 Lu v  +133.52
1991-10-04T14 Sa Pg +300.19
1991-10-05T19 Sa −d −20.64
1991-10-06T00 Ne −d −21.94
1991-10-07T09 Lu c  +194.10
1991-10-10T15
**
B  +114.29
1991-10-10T18 Me a  1.421
1991-10-10T22 Ma a  2.573
1991-10-12T12 Lu −d −25.09
1991-10-14T12 Lu xa +283.64
1991-10-14T22 Lu V  +288.53
1991-10-14T23 Lu a 0.002702
1991-10-14T23 Me xa +209.84
1991-10-22T23 Lu o  +29.52
1991-10-24T09
**
S  +153.25
1991-10-26T11 Lu v  +79.34
1991-10-26T11 Lu +d +24.98
1991-10-27T04 Lu p 0.002463
1991-10-28T02 Lu xd +102.22
1991-10-28T14 Ve xd +168.70
1991-11-01T18 Ve e  −46.52
1991-11-05T23 Lu c  +223.53
1991-11-07T21 Ma c  +225.48
1991-11-08T01
**
B  +97.15
1991-11-08T19 Lu −d −24.91
1991-11-10T15 Lu xa +281.04
1991-11-11T19 Lu a 0.002706
1991-11-11T22 Lu V  +296.12
1991-11-15T22 Ma xa +231.07
1991-11-18T14 Me e  +22.24
1991-11-20T19 Me −d −25.59
1991-11-21T10 Lu o  +59.14
1991-11-22T00
**
S  +138.79
1991-11-22T19 Lu +d +24.86
1991-11-23T07 Lu v  +86.58
1991-11-23T14 Lu p 0.002426
1991-11-24T06 Lu xd +100.31
1991-11-28T04 Me Rg +264.19
1991-12-03T15 Me xd +261.55
1991-12-05T15 Lu c  +253.54
1991-12-06T02 Lu −d −24.85
1991-12-06T04
**
B  +84.71
1991-12-07T20 Lu xa +279.89
1991-12-08T00 Me p  0.6783
1991-12-08T02 Me V  +256.04
1991-12-08T02 Me c  +256.02
1991-12-09T13 Lu a 0.002713
1991-12-09T18 Lu V  +302.36
1991-12-17T14 Me +d −18.77
1991-12-17T23 Me Pg +247.90
1991-12-20T00
**
S  +128.71
1991-12-20T05 Lu +d +24.87
1991-12-20T22 Lu o  +89.06
1991-12-21T15 Lu xd +99.83
1991-12-21T17
**
b  +92.62
1991-12-21T20 Lu v  +102.95
1991-12-21T21 Lu p 0.002395
1991-12-26T23 Ju −d +7.12
1991-12-27T13 Me e  −22.14
1991-12-30T08 Ju Rg +164.62

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Last updated: 2021-07-19