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46 FEBRUARY 2020 • SKY & TELESCOPE

FEBRUARY 2020 OBSERVING
Sun, Moon & Planets by Fred Schaaf

A

t nightfalls this month, Venus

keeps appearing higher in the

west-southwest, while Mercury peaks

far lower than Venus in the same direc-

tion at dusk during the fi rst part of the

month. Before and during dawn, there’s

a parade of three planets — Mars, then

Jupiter, and fi nally Saturn — rising

and getting farther away from the Sun

as the month progresses. The Moon

occults one of these planets — Mars

— for most of North America on the

morning of February 18th (though after

sunrise for some observers). Interest-

ingly, all fi ve bright planets cross the

ecliptic this month.

Five Ecliptic Crossings

All fi ve bright planets arrive at either ascending or descending node this month, but the

highlight for some lucky viewers might be the Moon’s occultation of Mars.

DUSK AND EVENING

Venus continues to appear higher at

each sunset, climbing from almost 35°

to a bit more than 41° in sunset altitude

during February as seen from around

latitude 40° north. At sunset, or even

earlier, is the best time to get a sharp

telescopic view of Venus, for its illumi-

nated part begins to dazzle against the

darker sky later in dusk. The angular

diameter of Venus increases from about

15 ′′ to 19′′ in February, while its illumi-

nated percentage decreases from about

73% to 63%. If you want to admire

the naked-eye spectacle of Venus in

a darker sky, you can fi nd its beacon

brightening from magnitude –4.1 to

–4.3 in February and, at mid-twilight,

hanging 30° high as the month begins

and about 35° as the month ends.

Venus doesn’t set until about 3^11 / 3 hours

after the Sun on February 1st and about

3¾ hours after on February 29th.

Even better days are ahead for view-

ers of Venus, for next month it reaches

the highest it ever does in its 8-year

cycle of recurring appearances. Then

in the fi rst few days of April the bright

planet skims along the southern edge of

the lovely Pleiades.

Mercury appears far lower than

Venus at nightfall in the fi rst two weeks

of February yet stands a satisfying 10°

above the west-southwestern horizon

shortly after sunset. From February 1st

to 14th, Mercury dims from magnitude

–1.0 to +0.2. The highlight of this fi ne

evening apparition of Mercury comes

on the 10th when the little planet

reaches a greatest eastern elongation of

18.2° from the Sun, and its 7′′-wide disk

is almost exactly half-lit.

46 FEBRUARY 2020 • SKY & TELESCOPE

To fi nd out what’s

visible in the sky

from your location,

go to skypub.com/

almanac.

Aldebaran

Rigel

Betelgeuse

ORION

TAURUS Moon

Feb 3

Moon

Feb 4

Looking Southeast, high in the sky

Dusk, Feb 3– 4

1 hour after sunset

10 °

Dusk, Feb 7

30 minutes after sunset

Mercury

Venus

Looking West-Southwest

SAGITTARIUS

Mars

Jupiter

Saturn

Moon

Feb 18

Moon

Feb 19

Moon

Feb 20

Looking Southeast

Occultation

near sunup for

North America!

30 minutes before sunrise

Dawn, Feb 18 –20