Sky and Telescope - July 2017 - 47
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Neptune rises in the late evening in
Aquarius and is highest in the south
in morning twilight. The dim planet is
moving slowly westward and lies about
2° east of Lambda (λ) Aquarii in July.
Uranus, in Pisces, rises in the middle
of the night and is still in the east as
dawn begins. See http://is.gd/urnep/ for
ﬁnder charts for Uranus and Neptune.
ORBITS OF THE PLANETS
Venus rises about 2½ hours before the
Sun as July opens and 3 hours before the
Sun as July closes. Its altitude an hour
before sunrise is already almost 20°.
This month, the brilliant planet
fades perceptibly from magnitude -4.2
to -4.0 as its gibbous phase increases
from 63% to 74% sunlit and its disk
shrinks from 18″ to 15″.
On July 5th, Venus beams about 7°
lower left of the Pleiades. During the
next week it skirts the Hyades, passing
just 3° north of Aldebaran on July 13th
and 14th. Venus approaches M35 in
Gemini as July ends.
Dawn, July 19-21
45 minutes before sunrise
The curved arrows show each planet's movement during July. The outer planets don't change
position enough in a month to notice at this scale.
Mars is at conjunction with the Sun
on July 27th - but exactly one year (to
the day) later Mars will be at perihelic
opposition, shining bigger and brighter
than it has at any time since 2003.
E A R TH A N D M O O N
Earth arrives at aphelion, its farthest
point from the Sun in space, at 4 p.m.
EDT on July 3rd. Earth's distance from
the Sun at aphelion is only 3.3% farther
than at perihelion in January.
The waxing gibbous Moon forms
a triangle with Jupiter and Spica on
the evening of July 1st. The nearly full
¢ Contributing Editor FRED SCHAAF
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Dusk, July 24 -25
Dusk, July 27-29
1 hour after sunset
30 minutes after sunset
TA U R U S
Moon beams just above Saturn on July
6th. The waning lunar crescent nears
Aldebaran and the Hyades at dawn on
July 19th, and it's about 3° lower right
of Venus the next morning. The waxing
crescent Moon hangs 4° to 5° lower
right of the Mercury-Regulus pairing
about 30 minutes after sunset on July
24th; good luck. It's much easier, about
8° upper left of the pair, the next evening. A thicker lunar crescent curves 3°
above Jupiter on July 28th.
s k y a n d t e l e s c o p e .c o m
* J U LY 2 017