Sky & Telescope - January 2020 - 46

JANUARY 2020 OBSERVING
Sun, Moon & Planets by Fred Schaaf
To find out what's
visible in the sky
from your location,
go to skypub.com/
almanac.

Planetary Prelude
The first month of this year provides a foretaste of some of the amazing sights to come.

he year 2020 shapes up to be truly
spectacular for the planets.
Jupiter and Saturn will pull close
together in May, separate, and then
come back together in December to have
their tightest conjunction in centuries.
Also in 2020, Venus passes through
the Pleiades near the apex of an outstanding evening apparition for observers at mid-northern latitudes. After
that, brilliant Venus moves over into
the morning sky for an almost equally
excellent dawn display.
Finally, Mars in 2020 glides close
past Jupiter and Saturn in March and in
the fall will appear almost as bright and
big in our sky as it was at the perihelic
opposition of 2018. But this time Mars
is 30° farther north and therefore much

sharper in telescopes for observers at
mid-northern latitudes.
Which planetary sights can you view
in this ﬁrst month of 2020? As January progresses, Venus comes into sight
higher and higher in the southwest at
nightfall. Mercury pokes into visibility
very low in the early evening twilight
near month's end. But after Venus sets
around mid-evening no bright planet is
visible until several hours before sunrise, when Mars rises in Libra, Scorpius,
or Ophiuchus. The last two bright planets follow Mars up at dawn but are only
just emerging from the solar glare as
January progresses: Jupiter around the
second week of the month and Saturn,
just barely for lucky binocular observers, at month's end.

q 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. The blue 10° scale bar is about the
width of your fist at arm's length. For clarity, the Moon is shown three times its actual apparent size.

Dusk, Jan 3

Dawn, Jan 4

45 minutes after sunset

45 minutes before sunrise

DUSK TO MID-EVENING
Venus has a dramatic increase in
sunset altitude for observers at midnorthern latitudes this month. If you
can already spot the planet's intense
spark as the Sun drops below the horizon, you'll ﬁnd it about 25° above the
southwestern horizon on January 1st
and about 34° high on the 31st. The
interval between sunset and Venus-set
increases from 2¾ hours to almost 3½
hours during January. You should be
able to tell in your eyepiece that the
planet has a gibbous phase that shrinks
from 82% to 74% lit and a disk that
enlarges from 13″ to 15″ during the
course of January.
Venus spends the month tracking past Delta (δ) Capricorni (Deneb

Dusk, Jan 6 - 8

Pleiades

1 hour after sunset
Moon
Jan 6

α Lib
Moon
Jan 7

b
10°

Venus

Aldebaran

Mars

TA U R U S

Moon
Jan 8

CAPRICORNUS

SCORPIUS

_
Antares

`
ORION
Betelgeuse

Looking Southwest

JANUARY 2 02 0 * SK Y & TELESCOPE

Looking Southeast

Looking East, halfway up

http://www.skypub.com/almanac http://www.skypub.com/almanac

Sky & Telescope - January 2020

Table of Contents for the Digital Edition of Sky & Telescope - January 2020