Astronomy

PATHOF THE

PLANETS

The planets

in the sky

These illustrations show the size, phase, and orientation of each planet and the two brightest dwarf planets

for the dates in the data table at bottom. South is at the top to match the view through a telescope.

The planets in December 2015

PER

AUR

TAU

ORI

CAE

COL

ERI

LEP

LY N

CNC

MON

PUP

PYX

VEL

ANT

CRT

HYA

SEX

LEO

OPH

HER

DRA

LY R

CEN

COM

BOÖ

SER

VIR

LIB

SCO

TEL

SCT

SER

LUP

CrB

CVn

LMi

UMa

CMi

CMa

Objects visible before dawn

Celestial equator

Path^

of^ the^ S

un^ (ecli

ptic)^

Path^

of^ the^ S

un^ (ecli

ptic)^

Moon phases Dawn Midnight

Sun

Saturn

Jupiter

Venus

Mars

Asteroid Psyche reaches

opposition December 9

The Moon occults Venus

in daylight December 7

Asteroid Euterpe reaches

opposition December 24/25

Nausikaa

Comet

Catalina

(C/2013 US10)

13 12 11 10 89 7 6 345 2 1

31 30 29 28 27 26 25 24 23

Venus

Mercury Mars

Ceres

Uranus

Saturn

Neptune

Pluto

10"

S

WE

N

Jupiter

40 ASTRONOMY • DECEMBER 2015

Planets MERCURY VENUS MARS CERES JUPITER SATURN URANUS NEPTUNE PLUTO

Date Dec. 31 Dec. 15 Dec. 15 Dec. 15 Dec. 15 Dec. 31 Dec. 15 Dec. 15 Dec. 15

Magnitude – 0. 5 – 4.1 1.4 9. 3 –2 .1 0. 5 5. 8 7.9 14. 2

Angular size 7.1" 15. 8 " 5 .1" 0. 4 " 37.1" 15. 3 " 3. 6 " 2. 3 " 0 .1"

Illumination 53% 72% 92% 98% 99% 100% 100% 100% 100%

Distance (AU) from Earth 0.947 1.054 1.845 3.489 5.316 10.868 19.557 30.207 33.915

Distance (AU) from Sun 0.330 0.719 1.663 2.977 5.413 10.011 19.977 29.960 33.003

Right ascension (2000.0) 20h02.4m 14h38.7m 13h11.3m 21h14.2m 11h32.8m 16h37.9m 1h01.4m 22h36.1m 19h01.2m

Declination (2000.0) –21°28' –13°04' –5°57' –24°49' 4°12' –20°27' 5°51' –9°41' –21°04'