46 AUSTRALIAN SKY & TELESCOPE May | June 2018
SUN, MOON & PLANETS by Jonathan NallyGiant worlds rule the night
The next few months will be a planet watcher’s paradise.
I
t’s a pretty good time for planet
watching at the moment, with Jupiter
to reach opposition in May, Saturn
the same in June, and Mars in July, with
all five naked-eye planets being evening
objects in June.
Mercury (magnitude 0.1 and
diameter 7.3 ̋ on May 1, mag. –0.2 and
6.5 ̋ by June 30) begins May still in the
eastern, morning sky. Rising about two
hours prior to sunrise at the start of the
month, the innermost planet will make
a nice sight on the 14th with the very
thin crescent Moon nearby. But by this
stage it will have drawn much closer
to the horizon and the Sun’s glare,
heading for superior conjunction (ie.
on the other side of the Sun) on June 6.
Returningtoourwestern,eveningsky
atmagnitude–0.8inthesecondhalf
of June, Mercury will be seen amongst
thestarsofGemini.TakealookontheSSaturn spends May and June close to
Messier 22.SJupiter, at opposition on May 9, rules
the sky.SVenuswillappearclosetoMessier44
on June 20.nights of June 24 to 26; the tiny planet
will appear close to the star Pollux.
Mercury will be brighter of the two, and
they’ll make a nice contrast.
Venus (–3.9, 12 ̋ to 14 ̋) will begin
May in the evening sky in Taurus before
spending the last week of the month
and all of June in Gemini. Along the
way it will pose for astrophotographers
as it passes a couple of nice star
clusters — the open cluster Messier 35
on May 21, and Messier 44 (also an
open cluster, and known variously as
Praesepe or the Beehive Cluster) on
June 20. Other picturesque encounters
will include the Moon (May 17 and
June 16), Aldebaran (May 2) and Pollux
(June 10). The planet will set around
7:0 0pm at the beginning of May, and
8:00pm by the end of June.
Mars(–0.7to–1.6,12.5 ̋to18 ̋),
heading for opposition in July, risesaround 10:00pm at the beginning of
May but by just after 7:00pm at the
end of June. The Red Planet moves
from Sagittarius to Capricornus during
this period, before starting two months
of retrograde motion at the end of
June. Watch for the Moon nearby on
May 6, and June 3 and 30. If you have
a telescope, have a look for the South
Polar Cap from the last week of May
onwards. May 23 marks the equinox on
Mars, when the southern hemisphere
begins the move from winter to
spring... bringing with it more solar
illumination for the southern half of
the planet.
Jupiter (–2.5, 44.8 ̋) is, of course,
the leader of the pack at the moment,
reaching opposition on May 9. Visible
allnight,thegasgiantwillmakeafine
sight whether you’re using a telescope,
binoculars or just the naked eye. Refer