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 at 0h UT

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

The planets in September 2017

EQU

LAC

AQR

MIC

AND

TRI

ARI

PER

AUR

TAU

ORI

PEG

PSC

CET

SCL

PHE

FOR

HOR

CAE

COL

ERI

LEP

LY N

GEM

CNC

MON

PUP

PYX

VEL

ANT

CRT HYA

SEX

LEO

CRV

COM

UMa

CVn LMi

PsA

CMI

CMa

Objects visible before dawn

Celestial equator

Path of th

e (^) Moon
Path of
the Su
n (ecli
ptic)
Sun
Moon phases Dawn Midnight
Uranus
Ceres
Mars
Venus
Mercury appears bright
in the morning sky
in mid-September
Iris
Pallas Neptune reaches its peak
in early September
Asteroid Julia reaches
opposition September 8
21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4
Venus
Mercury Mars
Ceres
Uranus
Saturn
Neptune
Pluto
10"
S
WE
N
Jupiter
40 ASTRONOMY • SEPTEMBER 2017
Planets MERCURY VENUS MARS CERES JUPITER SATURN URANUS NEPTUNE PLUTO
Date Sept. 15 Sept. 15 Sept. 30 Sept. 15 Sept. 15 Sept. 15 Sept. 15 Sept. 15 Sept. 15
Magnitude –0.7 –3.9 1.8 8.9 –1.7 0.5 5.7 7.8 14.2
Angular size 6.7" 11.8" 3.7" 0.4" 31.4" 16.6" 3.7" 2.4" 0.1"
Illumination 58% 87% 99% 97% 100% 100% 100% 100% 100%
Distance (AU) from Earth 1.010 1.419 2.557 3.069 6.269 10.026 19.087 28.955 32.976
Distance (AU) from Sun 0. 308 0.719 1.6 6 6 2.637 5.4 4 6 10.0 62 19.914 29.947 33.4 0 6
Right ascension (2000.0) 10 h27.1m 9h4 4.7m 11h07.9m 7h56.0m 13h32.1m 17h22. 3m 1h43. 3m 22h56. 3m 19h11.9m
Declination (2000.0) 10°42' 14°20' 6°51' 23°37' – 8°29' –22°02' 10°03' –7°48' –21°46'
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.