Mars MercuryPolluxCastorGEMINIJune 17, 45 minutes after sunset
Looking west-northwest5°ENPath of PallasJuly 1262116116June 162COMA BERENICESBOÖTES1°Pallas continues its nice run
Mercury tangos with Mars (^)
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Asteroid 2 Pallas glows at 9th
magnitude in June, making it a
nice target for asteroid seekers.
Visible with some effort through
binoculars, it’s a cinch to find
with the extra light-gathering
power of a small telescope.
Pallas lies high in the south
after darkness falls. To find it,
first locate Arcturus, the magni-
tude –0.04 orange giant in
Boötes that ranks as the night
sky’s fourth-brightest star. Next,
move 6.4° west-northwest to
5th-magnitude 6 Boötis, then
another 2.4° northwest to 6th-
magnitude 2 Boo. From there,
cross the border into eastern
Coma Berenices, Berenice’s Hair,
and star-hop to Pallas’ position
with the help of the chart below.
If you want to see the aster-
oid move in a single evening,
June 12 and 26 offer the best
chances. Both nights, Pallas
skims near a similarly bright star
that helps you gauge its motion.
When Heinrich Olbers dis-
covered Pallas in 1802, astrono-
mers thought it might be the
second “missing planet” in what
seemed like an abnormally large
gap between Mars and Jupiter.
Scientists later figured out that
the gravity of massive Jupiter
prevented any major planet
from forming at that distance
from the Sun.
LOCATINGASTEROIDS
Tangled up in Berenice’s tresses
four of them. Titan is the easi-
est. It shines at 8th magnitude
and shows up through any
instrument. This large moon
orbits Saturn in 16 days, pass-
ing south of the ringed world
the mornings of June 5 and 21
and north of the planet on the
13th and 29th. Look for three
10th-magnitude moons —
Tethys, Dione, and Rhea —
closer to Saturn.
Scan 60° east-northeast of
Saturn and you’ll arrive at
Neptune. The solar system’s
most distant major planet rises
shortly after 1 a.m. local day-
light time June 15 and climbs
25° above the southeastern
horizon by the time twilight
begins. Neptune glows at mag-
nitude 7.9, so you’ll need bin-
oculars or a telescope to see it.
The outer world resides in
northeastern Aquarius, in the
same binocular field as magni-
tude 4.2 Phi (φ) Aquarii. It
begins June 1.2° east-northeast
of this star and crawls 0.1° far-
ther away by the latter half of
the month. This places the
planet within 0.4° — slightly
less than the Full Moon’s
diameter — south of the mag-
nitude 5.6 star 96 Aqr. When
viewed through a telescope,
Neptune displays a blue-gray
disk that appears 2.3" across.
Uranus slowly emerges into
a dark sky by the end of June.
On the 30th, it rises around
2 a.m. local daylight time and
climbs 15° high in the east by
the time twilight starts to
paint the sky. The planet
shines at magnitude 5.8
and shows up quite easily
through binoculars.
The hardest part of finding
Uranus is zeroing in on the
right star field. The world lies
in southern Aries, about 10°
south of the Ram’s brightest
star, magnitude 2.0 Hamal
(Alpha [α] Arietis). This is a
sparse area of sky, however.
First locate 6th-magnitude
19 Ari, which lies 8° south of
Hamal and shows up to the
naked eye from under a dark
sky. Center 19 Ari in your
binoculars and you’ll see
Uranus 2.4° to its south.
To confirm your planet sight-
ing, swing a telescope in its
direction. Uranus shows a
3.5"-diameter disk with a dis-
tinctive blue-green color.
Morning twilight is well
underway before our final
planet appears. Venus rises
an hour before the Sun on
June 1 in the company of a
slender crescent Moon. The
two stand about 6° apart and
a similar distance above the
eastern horizon a half-hour
before sunrise. Although
Venus shines brilliantly at
magnitude –3.8, the Sun’s
glare drowns it out within
the next 15 minutes.
Venus slowly sinks lower
as the month progresses. It
stands just 3° high a half-hour
before sunup June 30, when
you’ll need a haze-free sky and
an unobstructed horizon to see
it against the twilight glow.
The inner planet is heading
toward its mid-August supe-
rior conjunction, and will dis-
appear from view in early July.
Earth reaches its summer
solstice at 11:54 a.m. EDT on
June 21. This marks the instant
when the Sun lies farthest
north in our sky, and is the
reason why the days are so
long and the nights so short in
the Northern Hemisphere.
Martin Ratcliffe provides plane-
tarium development for Sky-Skan,
Inc., from his home in Wichita,
Kansas. Alister Ling, who lives in
Edmonton, Alberta, has watched
the skies since 1975.
These two planets slide within 0.3° of each other June 18. They have not
passed this close in the evening sky since 2006.
This 9th-magnitude object rides high in the south on June evenings as
it traverses the sparse star fields of eastern Coma Berenices.