Astronomy

This map unfolds the entire night sky from sunset (at right) until sunrise (at left).

Arrows and colored dots show motions and locations of solar system objects during the month.

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.

Jupiter’s moons

Io

Europa

S

WE

N

Ganymede

Callisto

ILLUSTRATIONS BY

ASTRONOMY

: ROEN KELLY

SGR

SCT

SER

AQL OPH

HER

DRA

LY R

CYG

VUL

SGE

EQU

LAC

AQR

CAP

CAS

AND

TRI

ARI PEG

PSC

CET

SCL

PHE

FOR

GRU TEL SCO

PsA

CrA

Objects visible in the evening

Path of the Moon

Early evening

Sun

Uranus

Pluto

Neptune

Mercury appears bright in the

evening sky in late December

Laetitia

Amphitrite

Eunomia

Ceres

Vesta

22 21 20 19 18 17 16 15 14 13 12 11

1 2 3 4 5 6 7 8 9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

Callisto

Europa

Io

Ganymede

Jupiter

Mercury

Greatest eastern elongation

is December 28

Ceres

Mars

Uranus

Neptune

Saturn

Pluto

Venus

Jupiter

Jupiter

Earth

Winter solstice is

December 21/22

WWW.ASTRONOMY.COM 41

Dots display positions

of Galilean satellites at

5 A.M. EST on the date

shown. South is at the

top to match

the view

through a

telescope.

To locate the Moon in the sky, draw a line from the phase shown for the day straight up to the curved blue line.

Note: Moons vary in size due to the distance from Earth and are shown at 0h Universal Time.

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.