Sky & Telescope - January 2021 - 49

March 5: Mercury and Jupiter are
just 21′ apart, low in the east-southeast
at dawn. On this date, Jupiter will shine
at magnitude -2.0, and Mercury at
magnitude +0.1.
March 10: A thin, waning crescent
Moon joins the planetary trio of Mercury, Jupiter, and Saturn in morning
twilight. The group will span about 14°.
April 2: Jupiter's innermost moon, Io,
passes just 0.5″ south of the 5.9-magnitude star 44 Capricorni around
5:20 a.m. CDT. The event occurs with
Jupiter low in the southeastern sky and
favors observers in the middle of North
America. (From locations in Central
America and northern regions of South
America, Io occults the star.)
April 25: Mercury (magnitude -1.6)
and Venus (-3.9) are a little more than
1° apart very low in the western sky
during evening twilight.
April 26: A perigean full Moon (popularly called a "supermoon"), occurs
tonight. The Moon is full at 11:31 p.m.
EDT (3:31 UT, April 27th) and reaches
perigee (when it's closest to Earth) a
little less than 12 hours later, at a distance of 357,377 km (222,063 miles).
May 12: Venus and a very thin crescent Moon are only 1° apart, low in the
west-northwest at dusk.
May 26: A total lunar eclipse is
visible from western North America,
Polaris

though many other locations will be
able to see at least part of the event.
Because the Moon's northern limb is
barely inside the Earth's umbra, totality will be relatively bright and brief,
lasting from 4:11 a.m. to 4:26 a.m. PDT
(11:11 to 11:26 UT). As it happens, this
night also presents another "supermoon." The Moon is full (at 11:15 UT) a
little more than 9 hours after reaching
perigee, 357,310 km from Earth.
June 10: An annular solar eclipse
is visible in Canada, Greenland, and
Russia. The path of annularity crosses
mostly remote locations (including the
North Pole) except at its southern end
along the north shore of Lake Superior, where maximum eclipse occurs at
sunrise. Early risers in the northeastern
U.S. will see a dramatic sunrise with
roughly 80% of the Sun covered by the
Moon. Greatest eclipse (lasting 3 minutes 51 seconds) occurs at 10:42 UT.
June 23: Observers across North
America can see Mars (magnitude 1.8)
smack-dab in the middle of the Beehive Cluster (M44) in Cancer, low in
the northwestern sky at dusk. Use binoculars or a small, wide-ﬁeld telescope
to view this conjunction.
June 25: Skywatchers in the western
half of North America can watch the
nearly full Moon occult the 2nd-magnitude star Nunki (Sigma Sagittarii), in

Quadrantid Meteor Shower
Mizar

URSA
MINOR

Little
Dipper

1 am, Jan 3

URSA
MAJOR
10°
Quadrantid
radiant

DRACO

BOÖTES

HERC ULES

Arcturus

BOB KING

Looking Northeast
S This month's Quadrantid meteor shower will be hampered somewhat by light from a waning
gibbous Moon, which rises in the early evening on January 2nd. Given the timing of the display's
peak, the best time to look will be in the predawn hours of January 3rd.

2021 Returning Comets
Comet 7P/Pons-Winnecke makes
a favorable return in 2021 and may
reach magnitude 10 in the morning
sky as it shuttles from Aquarius to
Piscis Austrinus during mid- to late
June. Comet-watchers expect this
to be its best apparition in several
decades. You can begin searching for
the comet in northern Ophiuchus as
early as April.
Comet 6P/d'Arrest has a moderately
favorable return in 2021 and could
brighten to magnitude 9 at its peak
in late August and September as it
travels from southern Ophiuchus into
Sagittarius.
Comet 67P/Churyumov-Gerasimenko returns to the inner solar
system. This year's apparition is similar to the one it had in 1982, when the
comet reached 9th magnitude and
grew a pretty tail. On the night of perihelion (November 2nd) it's well placed
for viewing, positioned 3° southwest
of Pollux, in Gemini. Back in 1982,
watching the comet evolve inspired
me to track every future comet within
my telescope's reach.
S Comets as spectacular as last summer's
NEOWISE (C/2020 F3) are the exception
rather than the rule. The much more common fainter comets require telescopes to
see - including the trio of periodic comets
highlighted above.
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