Sky & Telescope - January 2021 - 47

16h

14h
12h
RI G HT A S CE NS I ON

Vega

8h
Castor
Pollux

BOÖTES

+30°

VIRGO

OPHIUCHUS

-10°

6
EC

LIP

Spica

Regulus

Pleiades

Procyon

PEGASUS

Neptune

Rigel
Sirius

CORVUS

CETUS

Fomalhaut

4 am

+20°
+10°
0°

AQUARIUS

Saturn
Jupiter

Mercury

CANIS
MAJOR

6 am

+30°

ERIDANUS

Antares

8 am

+40°
CYGNUS

PISCES

EQUATOR

ORION

HYDRA

10 am

22h

SCORPIUS

-40°

ARIES

TAURUS

Betelgeuse

Venus
SAGITTARIUS

Uranus

CANCER

0°
LIBRA

Mars
3

+10°
AQUILA

6h
GEMINI

Jan
28 -29

LEO

Arcturus

HERCULES

+20°

-30°

10h

D ECLI NATI O N

18h

+40°

2 am

Midnight

10 pm

8 pm

LOCAL TIME OF TRANSIT
6 pm
4 pm

CAPRICORNUS

-30°

2 pm

-40°

S The Sun and planets are positioned for mid-January; the colored arrows show the motion of each during the month. The Moon is plotted for evening dates in the Americas when it's waxing (right side illuminated) or full, and for morning dates when it's waning (left side illuminated). "Local time
of transit" tells when (in Local Mean Time) objects cross the meridian - that is, when they appear due south and at their highest - at mid-month.
Transits occur an hour later on the 1st, and an hour earlier at month's end.

MONDAY, JANUARY 11
There are two essential truths to every
Moon-Venus conjunction. First, they
always involve a crescent Moon, thanks
to the fact that Venus never strays terribly far from the horizon at dawn or
dusk, which is where the Moon hangs
out as either a waning or waxing crescent. Second, the encounters are reliably
beautiful - and the closer, the better.
For this morning's pairing, the
Moon is positioned less than 4° right
of Venus, which gleams impressively at
magnitude -3.9. That's close enough,
however, for both objects to ﬁt into the
ﬁeld of view of ordinary binoculars. The
lunar crescent will be razor-thin - just

Dusk, Jan 14 -16
30 minutes after sunset
Moon
Jan 16

a bit more than 3% illuminated, which
makes seeing earthshine very easy. The
one caveat to this show is that both
objects will be low in the southeast and
rise just one hour before the Sun. Worth
getting up early for, though!

WEDNESDAY, JANUARY 20
This evening the ﬁrst-quarter Moon
hangs roughly 6° below Mars, high in
the south. The later you look, the closer
the two objects will appear, since the
Moon is closing in on the Red Planet
and will pass as near as 3° to its south
at 4:50 a.m. EST on the 21st. Unfortunately, that's long after moonset, even
for observers on the West Coast. Still,
the contrast between the silvery-gray
Moon and peachy-orange Mars is striking to the unaided eye even when the
two objects are slightly farther apart.

Dusk, Jan 19 -21
1 hour after sunset

Moon
Jan 21

CAPRICORNUS

Mars

Moon
Jan 20

Moon
Jan 14
Mercury

CETUS

Jupiter

Looking Southwest

SATURDAY, JANUARY 23
Today Saturn is in conjunction with the
Sun. For naked-eye observers, the ringed
planet will become visible once again
at dawn in the latter part of February,
though binocular users will be able to
pick it out sooner.

THURSDAY, JANUARY 28
ARIES

Moon
Jan 15

As a bonus, binocular users should
set aside a little time to catch Uranus
positioned just a bit more than 1½°
south-southeast of Mars. At magnitude
5.8, Uranus is easy to identify because
it's the brightest dot of light that close
to and south of Mars. (There's a magnitude-5.7 ﬁeld star 42′ northwest of
Mars, but its location means it's hardly
likely to be mistaken for Uranus.) A
scope will easily reveal the planet's tiny
disk. If you have cloudy weather this
particular night, don't fret. Uranus will
be within 2° of Mars from the 18th to
the 22nd, inclusive.

Looking South,
almost overhead

Moon
Jan 19

Jupiter and Saturn have been together
since their historic close pairing in
December, so it's not surprising that
they're both in conjunction with the
Sun within a few days of each other.
Although Jupiter reaches this point ﬁve
days later (on the 28th), you'll likely
spot it emerging at dawn ﬁrst because
it's 10 times brighter than Saturn.
Consulting Editor GARY SERONIK
has been watching the night sky for
five decades and is author of the book
Binocular Highlights.
sk yandtelescope.org * JANUARY 2 021

http://www.skyandtelescope.org

Sky & Telescope - January 2021

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