Sky and Telescope - June 2017 - 47

* To ﬁnd out what's visible in the sky
from your location, go to skypub.com/
almanac.
latitudes must continue to deal with
Saturn at essentially its most southerly,
and therefore lowest, in the sky. Try for
your best observations between midnight and 2 a.m. (daylight-saving time),
when Saturn crosses the meridian at
its highest. This is also a good time to
check out the fascinating Milky Way
background, as the planet creeps westward in southeastern Ophiuchus away
from Sagittarius.
Neptune, in Aquarius, rises in the
middle of the night and by June 30th
stands about 40° high in the southeast
at the approach of morning twilight.

DAW N
Venus gleams in the east on June mornings, arriving at greatest elongation
(46° west of the Sun) on June 3rd. Its
visibility before sunrise isn't extremely
impressive, but viewers around latitude
40° north can watch Venus's altitude a
half hour before sunrise increase from
about 18° to 24° as the planet increases
its lead on the Sun from about 1 hour
and 45 minutes to a little more than 2
hours over the course of the month. An
improving angle of the ecliptic to the
dawn horizon will keep Venus's altitude
growing until early August, two full
months after greatest elongation.
Venus dims from magnitude -4.5
to -4.2 during June as its disk shrinks

December
solstice

Uranus

Mercury

Moon
June 20

Venus

March
equinox

Jupiter

Venus
Saturn

Neptune

Earth
June
solstice

ORBITS OF THE PLANETS
The curved arrows show each planet's movement during June. The outer planets don't change
position enough in a month to notice at this scale.

from about 24″ to 18″ wide. Its phase
thickens past 50% sunlit around the
time of greatest elongation.
A challenge for planet watchers at the
start of the month is Uranus. Shining
about 10 magnitudes or 10,000 times
fainter than Venus, it can be found
with a telescope less than 2° north or
northwest (upper left) of Venus on the
American mornings of June 2nd and 3rd.
The 3.5″ disk of Uranus would normally
be easy to distinguish from a star at
moderately high magniﬁcation. But in
early dawn when the sky is still dark
enough, you'll be looking very low where
everything is blurry.

Dusk, June 26 -28
LEO

1 hour after sunset

a
Sickle
Moon
June 27

Regulus

Pleiades
Moon
June 21

α Ceti

Moon
June 26

Moon
June 22

Looking East

Sept.
equinox

Sun

Moon
June 28

Dawn, June 20 -22
45 minutes before sunrise

Mars

Looking West

Mercury remains lost in glare of the
Sun. It will have a low, modest evening
apparition in July. Try for it on the last
day of June with binoculars.

SUN AND MOON
The Sun arrives at the June solstice at
12:24 a.m. EDT on June 21st (11:24 p.m.
CDT on the 20th), marking the shortest
night of the year and the start of summer in the Northern Hemisphere.
The waxing gibbous Moon poses
about 2° upper left of Jupiter at nightfall on June 3rd and 6° upper left of
Spica on June 4th. As evening twilight
deepens on June 7th, look for Beta (β)
Scorpii about 3° below the Moon.
The full Moon pairs with Saturn as
they rise in the southeast on the evening of June 9th. At dawn of the next
morning, June 10th, the Moon is 4°
upper left of the Ringed Planet.
On June 20th, the waning lunar
crescent cuts the morning twilight
about 7° right of Venus; it's 8° lower
left of Venus the next morning.
A waxing lunar crescent hangs about
1° from Regulus for North America on
the American evening of June 27th; it
occults Regulus for Hawai'i, Micronesia,
and parts of South America. The ﬁrstquarter Moon beams about 4° right of
Jupiter on June 30th.
¢ Contributing Editor FRED SCHAAF
welcomes your letters and comments at
fschaaf@aol.com.
s k y a n d t e l e s c o p e .c o m

* JUNE 2017

47
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Sky and Telescope - June 2017

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