Sky and Telescope - June 2018 - 47
wonders, such as one of the planet's
dusky polar caps or the narrow Encke
Gap in the A ring out beyond the wide
Cassini Division. The only problem
with these observations for viewers at
mid-northern latitudes is the lowness
of Saturn in the southern sky. The
planet still ﬂoats just above the Teapot
Asteroid 4 Vesta reaches opposition
on June 19th and is not just visible all
night long but is plainly visible with the
naked eye at a reasonably dark location.
This brightest of the asteroids reaches
a peak magnitude of 5.3 this month,
slightly brighter than it has been in
decades or will be again until 2031. See
page 48 for a ﬁnder chart and discussion.
Mars starts June less than two months
away from its closest approach to Earth
since 2003. How thrilling it is to see
Mars brighten from magnitude -1.2 to
-2.2 and swell from 15″ to more than
20″ wide in this one month. See the
upcoming July issue for information on
when and where to look for speciﬁc Martian surface and atmospheric features.
Mars rises around midnight as June
begins and around 10:30 p.m. as the
month ends. But the planet slows its
eastward motion in Capricornus and
then on June 28th halts and begins
westward (retrograde) motion.
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.
EVENING UNTIL DAWN
Neptune and Uranus get high enough
to observe by morning twilight (see
https://is.gd/urnep for a ﬁnder chart for
these outer giants).
SUN AND MOON
The Sun reaches the June solstice at
6:07 a.m. EDT on June 21st, starting
summer in the Northern Hemisphere
and winter in the Southern Hemisphere.
The waning gibbous Moon is a little
more than 3½° left or upper left of Saturn at dawn on June 1st and 2½° above
Mars at dawn on June 3rd. The very
thin waxing lunar crescent is almost 8°
to the left of Mercury, very low in the
west-northwest a mere half-hour after
sunset on June 14th. Bring binoculars
to see Mercury in conjunction with
the Moon. The next two evenings the
crescent Moon is 7½° lower right of
Venus and then again 7½° upper left of
Venus. The waxing gibbous Moon is less
than 5° upper left of Jupiter at nightfall
on June 23rd. The almost-full Moon is
only about 1° from Saturn at nightfall
on June 27th. On the ﬁnal American
evening of June, Mars and the waning
gibbous moon rise about 4½° apart.
¢ FRED SCHAAF enjoyed an awesome,
ultra-close conjunction of Mars and
Saturn 40 years ago this month.
Dusk, June 14 -15
June 22 - 24
June 26 -28
30 minutes after sunset
Looking South, halfway up
S A G I T TA R I U S
sk yandtelescope.com * J U N E 2 018