Sky.and.Telescope_

SkyandTelescope.com August 2014 49

To see what the sky looks like at any given time and date, go toSkyandTelescope.com/skychart. Fred Schaaf

Jupiter

Neptune

Uranus

Pluto

Saturn

March

equinox

Sept.

equinox

December

solstice

Mars June solstice

Earth

Mercury Sun

Venus

DAWN
Venus and Jupiter, the two brightest plan-
ets, have their closest conjunction since

2000. August starts with only Venus in
      sight at dawn; it’s low in the east-northeast
      but bright at magnitude –3.8. Jupiter was
      in conjunction with the Sun on July 24th,

and on August 1st it’s still too close to the

Sun to be visible without optical aid. But

Jupiter appears^2 / 3 ° higher each morning,

and a week into August it should be visible

to Venus’s lower left shortly before sunrise,

appearing dim in the bright twilight even

though it shines at magnitude –1.8.

Venus and Jupiter shine within 4° of

each other from August 14th through 21st.

They’re just 0.2° apart at their closest,

around 5h UT on August 18th, and they’re

still less than 0.3° apart a few hours later,

when they rise in eastern North America.

The majestic pair stands about 5° above

the horizon an hour before sunrise (for

skywatchers at about 40° north latitude).

At that hour, telescopes and binoculars

may also show the much fainter stars of

M44, the Beehive Cluster, just to their

left. The telescopic view of the planets

will improve as they rise higher and the

sky grows brighter. Venus, just 10′′ wide

and almost fully lit, will fi t easily in the

same fi eld of view at 100× with 32′′-wide

Jupiter. Note how much dimmer Jupiter

appears. It’s 7 times farther from the Sun,

so sunlight on Jupiter is just 2% as bright

as on Venus.

After that, Jupiter moves rapidly off to

Venus’s upper right, climbing into better

morning view as its year-long apparition

gets under way.

MOON PASSAGES

The Moon is a waxing crescent lower

right of Spica on August 1st and between

Mars and Spica on the 2nd. On August

3rd the nearly half-lit Moon lies between

Mars and Saturn.

The full Moon on August 10th is the

largest of the year, occurring almost pre-

cisely at perigee. At dawn on August 23rd,

the Moon forms a compact triangle with

Jupiter and Venus. On the 29th the lunar

crescent is back in the evening sky just

upper left of Spica, then forms a triangle

less than 5° on a side with Mars and Sat-

urn on August 31st.

The Moon occults Saturn in Australia

on the evening of August 4th and in west-

central Africa on the evening of the 31st.

It’s conceivable that telescopes will show

the August 31st occultation in the eastern

U.S. in broad daylight, a little after 1 p.m.

EDT. But even in Boston, on the northern

graze line, where the pairing is highest,

the 32%-lit crescent Moon will be just 15°

above the east-northeast horizon, making

it hard to spot. Dim Saturn will be much

more diffi cult. ✦

ORBITS OF THE PLANETS

The curved arrows show each planet’s movement during

August. The outer planets don’t change position enough

in a month to notice at this scale.

Dawn, Aug 18

45 minutes before sunrise

Castor

Procyon

Pollux

Venus

Jupiter

Looking East

Less than

(^1) ⁄ 2 ° apart!
Dawn, Aug 21–23
45 minutes before sunrise
Castor
Procyon
Pollux
Venus
Jupiter
Moon
Aug 21
Moon
Aug 22
Moon
Aug 23
Looking East