Sky and Telescope - July 2018 - 41
1 DAWN: Look toward the
southwest to see the waning
gibbous Moon and rusty Mars,
some 6°° apart, slowly disappear
from view as the sky brightens.
DUSK: Spot Mercury low on the
western horizon shortly after
sunset, where you will ﬁnd the
tiny world over the next 17 days.
6 EARTH is at aphelion,
farthest from the Sun for 2018,
at a distance of 152,095,566
9 EARLY EVENING: Venus
accompanies Regulus at a
separation of less than 1° as Leo,
the Lion, sinks in the west.
10 DAWN: The thin sliver of
the waning crescent Moon is
in the Hyades, a mere ½° from
Aldebaran, as they rise together
in the east; an occultation of the
red giant is visible in parts of
10-11 NIGHT: Jupiter arrives
at its stationary point - look
for it 2° right of the double star
Alpha (α) Librae; henceforth, the
giant planet slowly starts moving
eastward against the backdrop
11-12 NIGHT: Mercury achieves
a greatest eastern elongation
of 26°; it then fades from view
until re-emerging at dawn in late
15 DUSK: The waxing crescent
Moon and Venus, less than 2°
apart, trail Regulus by about 5°
as they descend in the west.
20 NIGHT: The waxing gibbous
Moon, giant Jupiter, and Alpha
Librae form a compact triangle
in the southwest.
24 NIGHT: The fat waxing
gibbous Moon visits Saturn in
Sagittarius, where the ringed
planet has lingered for the past
26-27 ALL NIGHT: Mars arrives
at opposition. Viewers in Europe,
Africa, and Asia are well placed
to witness an eclipsed Moon
pass some 6° above the planet;
see page 50.
30-31 ALL NIGHT: Mars comes
closer to Earth than it has
since 2003. Look in southwest
Capricornus to see the Red
Planet blazing at magnitude -2.8
and ﬂaunting a disk some
Gullies on Mars are commonly found at midlatitudes, especially in the southern highlands.
Carbon dioxide is thought to play a key role in
their formation. Missions such as NASA's HiRISE,
from which this image was taken, greatly help in
our understanding of these features.
NASA / JPL / UNIVERSITY OF ARIZONA
s k y a n d t e l e s c o p e . c o m * J U LY 2 0 1 8