Sky & Telescope - December 2020 - 44

DECEMBER 2020 OBSERVING
Planetary Almanac

PLANET VISIBILITY (40°N, naked-eye, approximate) Mercury: hidden in the Sun's glare all
month * Venus: is the leading light at dawn * Mars: transits the meridian in the early evening and sets
in the predawn * Jupiter: visible at dusk all month * Saturn: visible at dusk, sets in the early evening.

Mercury

Dec 1

21

11

December Sun & Planets

31

Date

Venus

1

Declination

Elongation

Magnitude

Diameter

Illumination

Distance

1

16h

29.0m

-21° 47′

-

-26.8

32′ 26″

-

0.986

31

18h

41.2m

-23° 06′

-

-26.8

32′ 32″

-

0.983

1

15h

45.3m

-19° 16′

11° Mo

-0.8

4.9″

96%

1.366

11

16h 50.5m

-23° 04′

5° Mo

-1.0

4.7″

99%

1.436

21

17h 59.0m

-24° 57′

2° Ev

-1.3

4.6″

100%

1.446

31

19h 09.7m

-24° 34′

7° Ev

-1.0

4.8″

98%

1.398

1

14h

38.1m

-13° 41′

28° Mo

-3.9

11.7″

89%

1.431

11

15h 27.4m

-17° 22′

25° Mo

-3.9

11.3″

91%

1.477

21

16h 18.8m

-20° 18′

23° Mo

-3.9

11.0″

92%

1.518

31

17h 11.9m

-22° 16′

21° Mo

-3.9

10.7″

94%

1.556

1

1h

01.9m

+6° 33′

128° Ev

-1.1

14.6″

92%

0.642

16

1h

16.4m

+8° 36′

117° Ev

-0.7

12.3″

90%

0.759

31

1h

37.6m

+11° 04′

107° Ev

-0.3

10.5″

89%

0.889

1

19h 51.8m

-21° 26′

47° Ev

-2.0

34.4″

100%

5.729

31

20h 18.6m

-20° 08′

23° Ev

-2.0

32.9″

100%

5.988

1

20h

01.2m

-20° 53′

49° Ev

+0.6

15.7″

100%

10.609

31

20h

14.2m

-20° 16′

22° Ev

+0.6

15.3″

100%

10.894

Uranus

16

2h

18.5m

+13° 21′

133° Ev

+5.7

3.7″

100%

19.095

Neptune

16

23h 17.4m

-5° 46′

84° Ev

+7.9

2.3″

100%

30.018

Sun

16

Mercury

31

Right Ascension

Mars

Venus
1

16

31

Jupiter

Mars

Jupiter

16
Saturn

Saturn
16
Uranus

Neptune

The table above gives each object's right ascension and declination (equinox 2000.0) at 0h Universal Time on selected dates,
and its elongation from the Sun in the morning (Mo) or evening (Ev) sky. Next are the visual magnitude and equatorial diameter.
(Saturn's ring extent is 2.27 times its equatorial diameter.) Last are the percentage of a planet's disk illuminated by the Sun and
the distance from Earth in astronomical units. (Based on the mean Earth-Sun distance, 1 a.u. equals 149,597,871 kilometers, or
92,955,807 international miles.) For other timely information about the planets, visit skyandtelescope.org.

PLANET DISKS have south up, to match the
view in many telescopes. Blue ticks indicate the
pole currently tilted toward Earth.
+40° 16 h
HERCULES

12h

14h

10 h

+30°

Regulus

8

+10°

EC

VIRGO

LIP

TIC

Venus

25

CANCER
Betelgeuse

11
Spica

Uranus

E Q U AT O R

ER I D A N US
CANIS
MAJOR

Antares

8 am

6 am

PE GASUS

Mars

TA U R U S

Mercury

SCORPIUS
- 40°
10 am

ARIES

Rigel

Sirius

CORVUS
H Y D R A

-30°

+40°
Vega
+30°

CYGNUS
Pleiades

ORION
LIBRA

20 h

22h
ASCENSION

PISCES

Procyon

0°
-10°

0h
RIGHT

2h

4h

5

LEO

Arcturus

+20°

6h

8h

GEMINI
Dec
Castor
29 - 30
Pollux

BOÖTES

DECLINATION

10"

4 am

2 am

Midnight

+20°
+10°
0°

Neptune A Q UA R I US

21

A Q UI LA

Saturn

CETUS

Jupiter

-10°

18
CA PR I CO R N US
Fomalhaut

LOCAL TIME OF TRANSIT
10 pm
8 pm
6 pm

4 pm

SAGITTARIUS

2 pm

-30°
-40°

The Sun and planets are positioned for mid-December; the colored arrows show the motion of each during the month. The Moon is plotted for evening dates in the Americas when it's waxing (right
side illuminated) or full, and for morning dates when it's waning (left side). "Local time of transit" tells when (in Local Mean Time) objects cross the meridian - that is, when they appear due south and
at their highest - at mid-month. Transits occur an hour later on the 1st, and an hour earlier at month's end.

44

DECEMBER 2 02 0 * SK Y & TELESCOPE


http://www.skyandtelescope.org

Sky & Telescope - December 2020

Table of Contents for the Digital Edition of Sky & Telescope - December 2020

Contents
Sky & Telescope - December 2020 - Cover1
Sky & Telescope - December 2020 - Cover2
Sky & Telescope - December 2020 - 1
Sky & Telescope - December 2020 - Contents
Sky & Telescope - December 2020 - 3
Sky & Telescope - December 2020 - 4
Sky & Telescope - December 2020 - 5
Sky & Telescope - December 2020 - 6
Sky & Telescope - December 2020 - 7
Sky & Telescope - December 2020 - 8
Sky & Telescope - December 2020 - 9
Sky & Telescope - December 2020 - 10
Sky & Telescope - December 2020 - 11
Sky & Telescope - December 2020 - 12
Sky & Telescope - December 2020 - 13
Sky & Telescope - December 2020 - 14
Sky & Telescope - December 2020 - 15
Sky & Telescope - December 2020 - 16
Sky & Telescope - December 2020 - 17
Sky & Telescope - December 2020 - 18
Sky & Telescope - December 2020 - 19
Sky & Telescope - December 2020 - 20
Sky & Telescope - December 2020 - 21
Sky & Telescope - December 2020 - 22
Sky & Telescope - December 2020 - 23
Sky & Telescope - December 2020 - 24
Sky & Telescope - December 2020 - 25
Sky & Telescope - December 2020 - 26
Sky & Telescope - December 2020 - 27
Sky & Telescope - December 2020 - 28
Sky & Telescope - December 2020 - 29
Sky & Telescope - December 2020 - 30
Sky & Telescope - December 2020 - 31
Sky & Telescope - December 2020 - 32
Sky & Telescope - December 2020 - 33
Sky & Telescope - December 2020 - 34
Sky & Telescope - December 2020 - 35
Sky & Telescope - December 2020 - 36
Sky & Telescope - December 2020 - 37
Sky & Telescope - December 2020 - 38
Sky & Telescope - December 2020 - 39
Sky & Telescope - December 2020 - 40
Sky & Telescope - December 2020 - 41
Sky & Telescope - December 2020 - 42
Sky & Telescope - December 2020 - 43
Sky & Telescope - December 2020 - 44
Sky & Telescope - December 2020 - 45
Sky & Telescope - December 2020 - 46
Sky & Telescope - December 2020 - 47
Sky & Telescope - December 2020 - 48
Sky & Telescope - December 2020 - 49
Sky & Telescope - December 2020 - 50
Sky & Telescope - December 2020 - 51
Sky & Telescope - December 2020 - 52
Sky & Telescope - December 2020 - 53
Sky & Telescope - December 2020 - 54
Sky & Telescope - December 2020 - 55
Sky & Telescope - December 2020 - 56
Sky & Telescope - December 2020 - 57
Sky & Telescope - December 2020 - 58
Sky & Telescope - December 2020 - 59
Sky & Telescope - December 2020 - 60
Sky & Telescope - December 2020 - 61
Sky & Telescope - December 2020 - 62
Sky & Telescope - December 2020 - 63
Sky & Telescope - December 2020 - 64
Sky & Telescope - December 2020 - 65
Sky & Telescope - December 2020 - 66
Sky & Telescope - December 2020 - 67
Sky & Telescope - December 2020 - 68
Sky & Telescope - December 2020 - 69
Sky & Telescope - December 2020 - 70
Sky & Telescope - December 2020 - 71
Sky & Telescope - December 2020 - 72
Sky & Telescope - December 2020 - 73
Sky & Telescope - December 2020 - 74
Sky & Telescope - December 2020 - 75
Sky & Telescope - December 2020 - 76
Sky & Telescope - December 2020 - 77
Sky & Telescope - December 2020 - 78
Sky & Telescope - December 2020 - 79
Sky & Telescope - December 2020 - 80
Sky & Telescope - December 2020 - 81
Sky & Telescope - December 2020 - 82
Sky & Telescope - December 2020 - 83
Sky & Telescope - December 2020 - 84
Sky & Telescope - December 2020 - Cover3
Sky & Telescope - December 2020 - Cover4
https://www.nxtbook.com/nxtbooks/aas/st_202112
https://www.nxtbook.com/nxtbooks/aas/st_202111
https://www.nxtbook.com/nxtbooks/aas/st_202110
https://www.nxtbook.com/nxtbooks/aas/st_202109
https://www.nxtbook.com/nxtbooks/aas/st_202108
https://www.nxtbook.com/nxtbooks/aas/st_202107
https://www.nxtbook.com/nxtbooks/aas/st_202106
https://www.nxtbook.com/nxtbooks/aas/st_202105
https://www.nxtbook.com/nxtbooks/aas/st_202104
https://www.nxtbook.com/nxtbooks/aas/st_202103
https://www.nxtbook.com/nxtbooks/aas/st_202102
https://www.nxtbook.com/nxtbooks/aas/st_202101
https://www.nxtbook.com/nxtbooks/aas/skywatch_2021
https://www.nxtbook.com/nxtbooks/aas/st_202012
https://www.nxtbook.com/nxtbooks/aas/st_202011
https://www.nxtbook.com/nxtbooks/aas/st_202010
https://www.nxtbook.com/nxtbooks/aas/st_202009
https://www.nxtbook.com/nxtbooks/aas/st_202008
https://www.nxtbook.com/nxtbooks/aas/st_202007
https://www.nxtbook.com/nxtbooks/aas/st_202006
https://www.nxtbook.com/nxtbooks/aas/st_202005
https://www.nxtbook.com/nxtbooks/aas/st_202004
https://www.nxtbook.com/nxtbooks/aas/st_202003
https://www.nxtbook.com/nxtbooks/aas/st_202002
https://www.nxtbook.com/nxtbooks/aas/st_202001
https://www.nxtbook.com/nxtbooks/aas/st_201912
https://www.nxtbook.com/nxtbooks/aas/st_201911
https://www.nxtbook.com/nxtbooks/aas/st_201910
https://www.nxtbook.com/nxtbooks/aas/st_201909
https://www.nxtbook.com/nxtbooks/aas/st_201908
https://www.nxtbook.com/nxtbooks/aas/st_201907
https://www.nxtbook.com/nxtbooks/aas/st_201906
https://www.nxtbook.com/nxtbooks/aas/st_201905
https://www.nxtbook.com/nxtbooks/aas/st_201904
https://www.nxtbook.com/nxtbooks/aas/st_201903
https://www.nxtbook.com/nxtbooks/aas/st_201902
https://www.nxtbook.com/nxtbooks/aas/st_201901
https://www.nxtbook.com/nxtbooks/aas/st_201812
https://www.nxtbook.com/nxtbooks/aas/st_201811
https://www.nxtbook.com/nxtbooks/aas/st_201810
https://www.nxtbook.com/nxtbooks/aas/st_201809
https://www.nxtbook.com/nxtbooks/aas/st_201808
https://www.nxtbook.com/nxtbooks/aas/st_201807
https://www.nxtbook.com/nxtbooks/aas/st_201806
https://www.nxtbook.com/nxtbooks/aas/st_201805
https://www.nxtbook.com/nxtbooks/aas/st_201804
https://www.nxtbook.com/nxtbooks/aas/st_201803
https://www.nxtbook.com/nxtbooks/aas/st_201802
https://www.nxtbook.com/nxtbooks/aas/st_201801
https://www.nxtbook.com/nxtbooks/aas/st_201712
https://www.nxtbook.com/nxtbooks/aas/st_201711
https://www.nxtbook.com/nxtbooks/aas/st_201710
https://www.nxtbook.com/nxtbooks/aas/st_201709
https://www.nxtbook.com/nxtbooks/aas/st_201708
https://www.nxtbook.com/nxtbooks/aas/st_201707
https://www.nxtbook.com/nxtbooks/aas/st_201706
https://www.nxtbook.com/nxtbooks/aas/st_201705
https://www.nxtbook.com/nxtbooks/aas/st_201704
https://www.nxtbook.com/nxtbooks/aas/st_201703
https://www.nxtbook.com/nxtbooks/aas/st_201702
https://www.nxtbook.com/nxtbooks/aas/st_201701
https://www.nxtbook.com/nxtbooks/aas/st_201612
https://www.nxtbook.com/nxtbooks/aas/st_201611
https://www.nxtbook.com/nxtbooks/newtrack/st_201612
https://www.nxtbook.com/nxtbooks/aas/st_201610
https://www.nxtbook.com/nxtbooks/aas/st_201609
https://www.nxtbook.com/nxtbooks/aas/st_201608
https://www.nxtbook.com/nxtbooks/aas/st_201607
https://www.nxtbook.com/nxtbooks/aas/st_201606
https://www.nxtbook.com/nxtbooks/aas/st_201605
https://www.nxtbook.com/nxtbooks/aas/st_201604
https://www.nxtbook.com/nxtbooks/aas/st_201603
https://www.nxtbook.com/nxtbooks/aas/st_201602
https://www.nxtbook.com/nxtbooks/aas/st_201601
https://www.nxtbook.com/nxtbooks/aas/st_201512
https://www.nxtbook.com/nxtbooks/aas/st_201511
https://www.nxtbook.com/nxtbooks/aas/st_201510
https://www.nxtbook.com/nxtbooks/aas/st_201509
https://www.nxtbook.com/nxtbooks/aas/st_201508
https://www.nxtbook.com/nxtbooks/aas/st_201507
https://www.nxtbook.com/nxtbooks/aas/st_201506
https://www.nxtbook.com/nxtbooks/aas/st_201505
https://www.nxtbook.com/nxtbooks/aas/st_201504
https://www.nxtbook.com/nxtbooks/aas/st_201503
https://www.nxtbook.com/nxtbooks/aas/st_201502
https://www.nxtbook.com/nxtbooks/aas/st_201501
https://www.nxtbook.com/nxtbooks/aas/st_201412
https://www.nxtbook.com/nxtbooks/aas/st_201411
https://www.nxtbook.com/nxtbooks/aas/st_201410
https://www.nxtbook.com/nxtbooks/aas/st_201409
https://www.nxtbook.com/nxtbooks/aas/st_201408
https://www.nxtbook.com/nxtbooks/aas/st_201407
https://www.nxtbook.com/nxtbooks/aas/st_201406
https://www.nxtbook.com/nxtbooks/aas/st_mars
https://www.nxtbook.com/nxtbooks/aas/st_201405
https://www.nxtbook.com/nxtbooks/aas/st_201404
https://www.nxtbook.com/nxtbooks/aas/st_201403
https://www.nxtbook.com/nxtbooks/aas/st_201402
https://www.nxtbook.com/nxtbooks/aas/st_201401
https://www.nxtbook.com/nxtbooks/aas/st_201312
https://www.nxtbook.com/nxtbooks/aas/st_201311
https://www.nxtbook.com/nxtbooks/aas/st_201310
https://www.nxtbook.com/nxtbooks/aas/st_201309
https://www.nxtbook.com/nxtbooks/aas/st_201308
https://www.nxtbook.com/nxtbooks/aas/st_201307
https://www.nxtbook.com/nxtbooks/aas/st_201306
https://www.nxtbook.com/nxtbooks/aas/st_201305
https://www.nxtbook.com/nxtbooks/aas/st_201304
https://www.nxtbook.com/nxtbooks/aas/st_201303
https://www.nxtbook.com/nxtbooks/aas/st_201302
https://www.nxtbook.com/nxtbooks/aas/st_201301
https://www.nxtbook.com/nxtbooks/aas/st_201212
https://www.nxtbook.com/nxtbooks/aas/st_201211
https://www.nxtbook.com/nxtbooks/aas/st_201210
https://www.nxtbook.com/nxtbooks/aas/st_201209
https://www.nxtbook.com/nxtbooks/aas/st_201208
https://www.nxtbook.com/nxtbooks/aas/st_201207
https://www.nxtbook.com/nxtbooks/aas/st_201206
https://www.nxtbook.com/nxtbooks/aas/st_201205
https://www.nxtbook.com/nxtbooks/aas/st_201204
https://www.nxtbook.com/nxtbooks/aas/st_201203
https://www.nxtbook.com/nxtbooks/aas/st_201202
https://www.nxtbook.com/nxtbooks/aas/st_201201
https://www.nxtbook.com/nxtbooks/aas/st_201112
https://www.nxtbook.com/nxtbooks/aas/st_201111
https://www.nxtbook.com/nxtbooks/aas/st_201110
https://www.nxtbook.com/nxtbooks/aas/st_201109
https://www.nxtbook.com/nxtbooks/aas/st_201108
https://www.nxtbook.com/nxtbooks/aas/st_201107
https://www.nxtbook.com/nxtbooks/aas/st_201106
https://www.nxtbook.com/nxtbooks/aas/st_201105
https://www.nxtbook.com/nxtbooks/aas/st_201104
https://www.nxtbook.com/nxtbooks/aas/st_201103
https://www.nxtbook.com/nxtbooks/aas/st_201102
https://www.nxtbook.com/nxtbooks/aas/st_201101
https://www.nxtbook.com/nxtbooks/aas/st_201012
https://www.nxtbook.com/nxtbooks/aas/st_201011
https://www.nxtbook.com/nxtbooks/aas/st_201010
https://www.nxtbook.com/nxtbooks/aas/st_201009
https://www.nxtbook.com/nxtbooks/aas/st_201008
https://www.nxtbook.com/nxtbooks/aas/st_201007
https://www.nxtbook.com/nxtbooks/aas/st_201006
https://www.nxtbook.com/nxtbooks/aas/st_201005
https://www.nxtbook.com/nxtbooks/aas/st_201004
https://www.nxtbook.com/nxtbooks/aas/st_201003
https://www.nxtbook.com/nxtbooks/aas/st_201002
https://www.nxtbook.com/nxtbooks/aas/st_201001
https://www.nxtbookmedia.com