Sky & Telescope - June 2021 - 46

JUNE 2021 OBSERVING
Sun, Moon & Planets by Gary Seronik
To find out what's
visible in the sky from
your location, go to
skyandtelescope.org.

Venus and Mars Steal the Dusk Show
Two early-evening planets highlight an eventful month.
TUESDAY, JUNE 1

SUNDAY, JUNE 13

If you like to do your observing before
sunrise, you'll be rewarded straightaway in June. Cast your gaze toward
the southeast at the start of morning
twilight to catch the (almost) lastquarter Moon hanging some 5° below
right of Jupiter. This is a ﬁne naked-eye
sight. Jupiter gleams at magnitude -2.4,
so it stands up well to moonlight and
even bright twilight. As a bonus, Saturn
is located about 18° to the right of the
twosome.

Echoing last month's sequence of
events, after its encounter with Venus,
the Moon next joins Mars. Thanks to
Venus's relatively rapid eastward drift,
the gap between it and the Red Planet
is shrinking. As a result, early this
evening the Moon pulls up alongside
Mars only two nights after its meeting with Venus - compare that to May
when there was a three-night gap. Come
July, Venus catches up to Mars so that
the Moon can visit both planets on the
same night. On June 13th, however, the
earthlit lunar crescent will be a little
less than 3° above Mars, which shines
at magnitude 1.8 - about half as bright
as Pollux in Gemini, which is some 10°
to the planet's right. In addition, if you
get out your binoculars you should just
be able to squeeze the Moon into the
same view as the pretty open cluster

FRIDAY, JUNE 11
Whenever Venus is favorably placed,
skywatchers are treated to the monthly
spectacle of a conjunction between the
Evening Star and crescent Moon. Generally, only one such encounter happens
each calendar month, though every couple of years we get two. Not this time.
However, this month's lone VenusMoon pairing is a nice one, featuring a
very young (1.6-day-old, 2.3%-illuminated) lunar crescent sitting 3° lower
right of the magnitude -3.8 planet at
dusk. It's still early days in the current
apparition, though, so Venus hasn't yet
had the chance to climb very high yet.
That means you'll need an unobstructed
west-northwest horizon to see this
Venus-and-Moon show.
If you use binoculars, you can seek
them out only minutes after sunset,
when they're at their highest, about 13°
up. Because Venus maintains a nearly
constant altitude after sunset over the
next several months, its lunar meet-ups
will continue to occur near the horizon.
The main difference is the early-evening
lunar crescent will be increasingly older
(and fatter) as the year progresses.
46

JUNE 2 021 * SK Y & TELESCOPE

M44, in Cancer. The cluster will also
ﬁgure in one of June's more interesting
sights on the 23rd (see next page).

THURSDAY, JUNE 17
Asteroid hunters have a great opportunity to spot Vesta this evening. It's the
brightest asteroid and currently shines
at magnitude 7.6 - easily within reach
of ordinary binoculars. What makes it
an especially tempting target tonight is
that it's found only 1.3° north-northeast of 4th-magnitude Iota Leonis and is
positioned as the middle dot in a threein-a-row conﬁguration that includes
stars of magnitudes 5.8 and 6.5. (Iota
is shown - though not labeled - on
our center star chart, below and right
of Denebola.) A ﬁnder chart for Vesta
appeared in the March issue (page 48),
which plots Iota and the two fainter
stars. The best way to be sure you're

TX These scenes are drawn for near the middle of North America (latitude 40° north, longitude
90° west). European observers should move each Moon symbol a quarter of the way toward the
one for the previous date; in the Far East, move the Moon halfway.

Dusk, June 11-13

Dusk, June 21

45 minutes after sunset

Moon
June 13
Mars

GEMINI
Castor

Pollux

Mars

Moon
June 12

GEMINI
Pollux

10°
Venus
Procyon

Castor

Venus

Moon
June 11

Looking West-Northwest

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Sky & Telescope - June 2021

Table of Contents for the Digital Edition of Sky & Telescope - June 2021