Sky and Telescope - February 2016 - 42

OBSERVING

Sun, Moon & Planets

Jupiter Blazes in the Night
Look to the morning for the other bright planets.
February begins with no bright planets in the sky at dusk, but as the month
progresses, brilliant Jupiter begins rising
due east in evening twilight. Mars doesn't
come up until the midnight hour, when
its increasing brightness and color draw
our attention. Jupiter reaches its highest
after Mars appears, and Mars is followed by similarly bright Saturn, rising
in Ophiuchus. Finally, two hours or less
before the Sun comes up, Venus rises,
followed closely by Mercury, lifting all the
bright planets into visibility at once.

DUSK AND EVENING
Jupiter is gloriously bright and visible this month. It climbs over the east
horizon around 8 or 9 p.m. local time
as February begins but only about 25
minutes after sunset as the month ends.
It brightens a trace from magnitude -2.4
to -2.5 while its apparent diameter in
telescopes grows two arcseconds - from
more than 42″ to more than 44″ - before
month's end. The kingly planet now is
retrograding (moving westward against

Moon
Feb 1

`Lib
Moon
Feb 2

Mars

Moon
Feb 4

Moon
Feb 5

_Lib
`
Moon
Feb 6

b

/ Sgr

SCORPIUS

Looking South, partway up

Februar y 2016 sky & telescope

S A G I T TA R I U S

Venus

10°

Antares

42

Mars starts February 1.1° north of the
3rd-magnitude double star Alpha (α)
Librae (Zubenelgenubi) and moves eastward - most of the way across Libra -
over the course of the month. Its time of
rising backsteps less than an hour during
the same period, from near 1 a.m. at the
start of the month to midnight at the end.
Mars shines in the large gap between
Spica and Antares, kindling from slightly
brighter than these stars to approximately twice as bright. Its magnitude
improves from +0.8 to +0.3 this month, a
brightness range in which the campﬁre
orange-gold color becomes more prominent to the naked eye. The angular size

45 minutes before sunrise

1 hour before sunrise

Saturn

L AT E N I G H T T O D AW N

Dawn, Feb 4 - 6

Dawn, Feb 1-3

Moon
Feb 3

the stars) in southeastern Leo; it will
reach opposition and come closest to
Earth on March 8th.
Dim Uranus is still visible in February
as evening twilight ends. Find it with the
charts in last September's issue, page 48,
or at skypub.com/urnep. Neptune is lost
in evening twilight this month.

Mercury

Looking Southeast

of Mars grows only from 6.8″ to 8.6″
during February, so you'll need a good
telescope, good seeing, and Mars near its
highest - which it reaches in morning
twilight - to glimpse a surface feature
other than the north polar ice cap. You
may also notice that Mars looks slightly
out-of-round this month because of a
shadowed edge caused by our line of sight
to it diﬀering from the Sun's. Mars is at
western quadrature (90° west of the Sun)
on February 7th.
Mars is on its way to opposition on May
22nd and a closest approach to Earth on
May 30th, when it will reach 18.6″ in diameter and shine almost as bright as Jupiter.
Saturn rises after 3 a.m. as February
opens and around 1:30 a.m. as it closes.
The golden planet starts the month only
7½° northeast of Antares, then creeps a
bit eastward from the noticeably dimmer
star over the course of a few weeks. Saturn
maintains a magnitude +0.5 all month,
providing an interesting brightness comparison to Mars. Its rings are now tilted
a glorious 26° from edgewise. Telescopic
observations are best made at the beginning of dawn, when Saturn approaches
the meridian.

DAWN
Venus is nearing the end of a long morning apparition, rising before morning
twilight at the beginning of February but
only an hour before sunrise at the end.
The angle of the ecliptic with respect to
the eastern horizon is shallow at dawn this
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. 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.
http://www.skypub.com/urnep
Sky and Telescope - February 2016

Table of Contents for the Digital Edition of Sky and Telescope - February 2016
