AUR
TAU
ORI
COL
LEP
SCT
SER
AQL
LY R
CYG
VUL
DEL SGE
LY N
GEM
CNC
ANT PYX PUP
CRT
HYA
SEX
LEO
OPH
HER
DRA
CRV
COM
BOÖ
SER
VIR
LIB
LUP
TEL
SGR
EQU
AQR
CAP
MIC
CrB
CVn
CMA
UMa
Path^ o
f the^ S
un^ (ec
liptic
)^
Path
of^ th
e^ Moo
n^
Celestial equator
Sun
Moon phases Dawn Midnight
Pluto
Saturn Jupiter
Mars
Asteroid Astraea reaches
opposition January 20/21
Asteroid Davida reaches
opposition January 14/15
Ceres
25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8
Mercury Mars
Venus
Ceres
Mars
Uranus
Neptune
Venus
Jupiter
Jupiter
Earth
Perihelion
is January 5
Pluto
Solar conjunction
is January 13
Saturn
Solar conjunction
is January 13
Mercury
Superior conjunction
is January 10
Ceres
Solar conjunction
is January 13
40 ASTRONOMY • JANUARY 2020
THE PLANETS
IN THEIR ORBITS
Arrows show the inner
planets’ monthly motions
and dots depict the outer
planets’ positions at mid-
month from high above
their orbits.
To locate the Moon in the sky, draw a line from the phase shown for the day straight up to the curved blue line.
Date
Magnitude
Angular size
Illumination
Distance (AU) from Earth
Distance (AU) from Sun
Right ascension (2000.0)
Declination (2000.0)
PLANETS
Jan. 31
–1.0
5.5"
87%
1.212
0.348
21h47.3m
–14°46'
Jan. 15
–4.0
13.9"
79%
1.196
0.725
22h15.3m
–12°31'
MERCURY VENUS
PATHS OF THE PLANETS
THE PLANETS IN THE SKY
These illustrations show the size, phase,
and orientation of each planet and the two
brightest dwarf panets at 0h UT for the dates
in the data table at bottom. South is at the top
to match the view through a telescope.