2019-06-01+Sky+and+Telescope

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46 JUNE 2019 • SKY & TELESCOPE


JUNE 2019 OBSERVING
Sun, Moon & Planets by Fred Schaaf


F


our bright planets adorn the sky
during evening twilight in the lat-
ter half of June. Mars hangs low in the
west-northwest in evening twilight this
month, with much brighter Mercury
passing close by. Jupiter reaches opposi-
tion on June 10th^ and so is visible all
night at its brightest and biggest. Saturn
trails Jupiter by about two hours and
rises as little as 30 minutes after the
Sun sets at month’s end. Venus gives
us a last good look in the brightening
dawn sky before the Morning Star fades
from view in late July.

DUSK
Mars and Mercury are a fascinating
pair in the west-northwest at evening
twilight in June. Mars remains at mag-
nitude 1.8 all month, and the interval

Plentiful Planets


All fi ve bright planets are on display this month — four accompany us
during the evening hours, and one greets us at dawn.

between sunset and Mars-set shrinks
from about 2¼ to 1¼ hours during June.
As Mars appears a little lower at any
given time in dusk with each passing
day, Mercury appears higher. The tiny
world starts the month far below Mars,
setting about 65 minutes after the Sun
but shining at magnitude –1.0. Mercury
fades to magnitude +0.1 by June 17th
when it appears just ¼° from Mars. The
next evening, Mercury is even closer to
Mars. By the 19th, the gap between the
planets has increased to ¾°. On these
dates, Mercury is about half-lit and a bit
more than 7′′ across.
Find Mercury about 6° lower left
of much dimmer Pollux on June 20th
(Mars is the same distance lower left of
Pollux on June 22nd). Mercury reaches
a greatest eastern elongation of 25°

from the Sun on June 23rd. You’ll no
doubt need binoculars near month’s end
to spot Castor and Mars as the latter
moves into a nearly horizontal line with
Mercury (magnitude 1.0 as June ends),
Pollux, and Castor.

DUSK TO DAWN
Jupiter reaches opposition on June
10th and so rules the entire night with
its brilliance and, in telescopes, its size
this month. Throughout June, Jupiter
burns at magnitude –2.6 and its globe
measures about 46′′ wide. This is a little
brighter and bigger than the king of the
planets has been in fi ve years.
The only negative factor in this
month’s (and year’s) display of Jupiter
for observers at mid-northern latitudes
is the extreme southerliness of the

46 JUNE 2019 • SKY & TELESCOPE


To fi nd out what’s
visible in the sky
from your location,
go to skypub.com/
almanac.

Regulus

Denebola

LEO

Moon
June 7

Moon
June 8

Moon
June 9

June 7– 9
Around 10 pm

Looking West, halfway up

10 ° Sickle

Antares
Jupiter

Moon
June 14

Moon
June 15

Moon
June 16

Looking Southeast

Dusk, June 14 –16
1 hour after sunset

SCORPIUS SAGITTARIUS

Saturn

Moon
June 17

Moon
June 18

Looking South-Southeast

June 17–18
Late, toward midnight
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