Sky & Telescope - January 2019 - 47

Venus appears to plummet past Jupiter,
from Libra down through Scorpius.
Around January 12th, Venus passes by
Scorpius's head and forms the peak of a
tall triangle with Jupiter and Antares as
the base corners of the triangle. Then,
around January 19th, Venus is 3¾°
above Jupiter, with Antares at just about
the same altitude as Jupiter, forming a
squat right triangle.
Venus and Jupiter are a minimum
of 2½° apart on January 22nd. Telescopes then show Venus's dazzlingly
bright form as 21″ across and about
60% lit. Jupiter's much duller but fully
lit disk is 33″ wide.
On January 26th viewers at midnorthern latitudes can see Venus,
Jupiter, and Antares form a horizontal
line, with a little more than 4° separating the two planets and twice again that
distance between Jupiter and the star.
By January 31st, the gap between Venus
and Jupiter has widened to 9½°, with
Jupiter to the upper right of Venus, rising almost half an hour before Venus.

DAWN
Mercury glimmers around 5½° high in
the southeast a mere 30 minutes before

December
solstice

Uranus

Venus
March
equinox

Jupiter
Neptune

Saturn

The curved arrows show each planet's movement during January. The outer planets don't
change position enough in a month to notice at this scale.

sunrise on the opening days of 2019. It
then shines as the bottom-left planet in
a long diagonal line equally spaced with
Venus and Jupiter. Mercury brightens,
from magnitude -0.4 to -0.7, in the
ﬁrst half of January but is simply too
low in strong twilight glow to be seen
after the 3rd or 4th. Mercury reaches
superior conjunction with the Sun on
the night of January 29-30.
Saturn is in conjunction with the
Sun on January 2nd so isn't visible

Moon
Jan 29

45 minutes before sunrise

Moon
Jan 30

Jupiter
Antares

SCORPIUS
Moon
Feb 1

S A G I T TA R I U S
Moon
Feb 2

Saturn

Looking Southeast

Mercury

ORBITS OF THE PLANETS

Dawn, Jan 29 - Feb 2

Venus

Sept.
equinox

Sun

June
solstice

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.

Moon
Jan 31

Mars

Earth

C a t 's
Eyes

Looking South-Southeast

when it passes less than 2° from Mercury on January 13th. The ringed planet
emerges into visibility in morning
twilight around the third week of the
month. The +0.6-magnitude world has
increased its lead on the Sun to more
than 1½ hours by month's end.

EARTH, SUN, AND MOON
Earth comes to perihelion, a minimum
of 0.98 a.u. (speciﬁcally, 147,099,761 km)
from the Sun, at 5h UT on January 3rd.
The Sun is partially eclipsed for
observers in parts of eastern Asia,
Micronesia, and the Aleutian Islands on
January 5-6 (see page 50 for details).
The Moon is totally eclipsed on the
night of January 20-21; for full information, see page 18. The waning lunar
crescent is 5° upper right of Venus on
January 1st and slightly farther, around
7°, lower left the next morning. The
slim lunar sliver is 3° to 4° left of Jupiter on January 3rd and around 3° above
a low Mercury a mere half-hour before
sunrise on January 4th. The thick waxing crescent Moon is some 5° lower left
of Mars on January 12th. The waning
Moon crescent is 6° to 7° upper right
of Jupiter on January 30th and the next
morning between Jupiter and Venus,
around 2° to the right of Venus.
¢ Contributing Editor FRED SCHAAF
was six years old when he saw his first
lunar eclipse (one that at the time was
officially listed as total) in August 1961.
sk yandtele scope.com * JA N UA RY 2 019

http://www.skyandtelescope.com

Sky & Telescope - January 2019

Table of Contents for the Digital Edition of Sky & Telescope - January 2019