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48 March 2014 sky & telescope

OBSERVING

Sun, Moon && Planets

The amazing, rare occultation of Regu-

lus by the minor planet 163 Erigone is

visible only along a narrow path from

the New York City area through eastern

Ontario and points north; see page 30. But

everyone in the Northern Hemisphere

can enjoy fi ne views of the major planets

in March. Jupiter is near its highest in the

south at dusk. Mars becomes very bright

and starts to rise in the early evening. Sat-

urn rises about 2 hours after Mars. And,

last of all, Venus and Mercury appear low

in morning twilight.

DUSK

Jupiter is best viewed this month at

nightfall, when it’s near the meridian.

Although it fades a bit (from magnitude

–2.4 to –2.2) and shrinks a bit (from 42′′ to

39 ′′ wide), Jupiter at dusk is just about as

high as it can ever be for observers at mid-

northern latitudes — and it remains quite

The Red Planet Approaches

Mars doubles in brightness during the month of March.

Dusk, March 6 –10

1 hour after sunset

Aldebaran

Rigel

Betelgeuse

Sirius

Jupiter

Moon

March 6

Moon

March 7

Moon

Moon March 8

March 9

Moon

March 10

ORION

Hyades

Pleiades

Looking South, high in the sky

10 °

γ Gem

high throughout the evening. Jupiter is

stationary in right ascension on March 6th

and then slowly resumes direct (eastward)

motion relative to the stars. So it spends

the entire month about 2° south or south-

southeast of the 3.0-magnitude supergiant

star Epsilon Geminorum (Mebsuta).

Uranus, in Pisces, will reach conjunc-

tion with the Sun on April 2nd. It can

be glimpsed in evening twilight in early

March but is soon lost to view.

EVENING TO DAWN

Mars becomes dramatically bright during

March, its magnitude improving from

–0.5 to –1.3 on its way to an April 8th

opposition. The “Red Planet” rises about

3½ hours after sunset as March opens,

but it comes up in bright twilight by the

time the month closes. Mars begins to

retrograde (move westward against the

stars) on March 1st, when it’s 6° northeast

of Spica. It begins to pick up speed in

its westward trek through Virgo, ending

March 5° to Spica’s north.

In telescopes Mars’s globe increases

from 11.6′′ to 14.6′′ wide, off ering telescopic

views of its surface features when the see-

ing is good. See the guide on page 50.

Saturn rises in Libra before midnight

and shines highest 2 to 3 hours before

sunrise. Saturn brightens from magni-

tude +0.4 to +0.3, and its equatorial diame-

ter nudges over 18′′. Saturn’s rings remain

generously tilted 22° from edge-on.

Saturn reaches its stationary point and

begins retrograde motion on March 3rd

— just two days after Mars. In fact, by an

odd coincidence, four planets and the two

brightest asteroids, Ceres and Vesta, all

halt their motion in right ascension dur-

ing a period of 8 days: Mercury (February

27th), Ceres and Mars (March 1st), Saturn

(March 3rd), Vesta (March 5th), and Jupi-

ter (March 6th). Ceres and Vesta spend the

spring just a few degrees apart and will

have a marvelous close encounter in the

sky in early summer, as described in the

February issue, page 50.

DAWN

Venus and Mercury shine low in the east

at dawn in March. Venus is bright and

easy to spot. Mercury is far to Venus’s

lower left — tricky to spot early in the

month and probably impossible without

optical aid after March 18th.

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 fi st at arm’s length.

For clarity, the Moon is shown three times its

actual apparent size.

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