Skylights featured three times on Earth Science
Picture of the Day: 1
, 2
, 3
, 4
.
Photo of the Week.. Sometimes we look down to look
up, here at the reflection of the sky in a pond.
Astronomy news for the week starting Friday, July 4, 2003.
Happy Birthday. Skylights is presented a day early this
week.
We begin the week just barely past
aphelion, where the Earth is farthest from the Sun, a distance
of 152.1 million kilometers, 94.5 million miles, 1.7 percent
farther than average.
Closer to home, the Moon waxes through its late crescent phase very
early in the week, and then passes first
quarter the night of Sunday, July 6, about as twilight ends in
North America. The remainder of the week sees it waxing through
its gibbous phase toward full, which will be attained next week.
Watch the Moon as it passes through prominent Scorpius the night of Thursday the 10th, appearing just
up and to the left of bright Antares, which will be all but
swamped in moonlight.
Jupiter
is now setting about as astronomical twilight ends (when the sky if fully
dark). Though slowly disappearing into the evening glow, it
remains quite visible in the west after sundown. But not for long.
In the morning sky, Jupiter's near twin, Saturn, is clearing the Sun, though it is still less than readily visible. The
morning of Tuesday the 8th, Saturn will be in close conjunction
with Venus
, the ringed planet passing less than a degree to the south of
our brilliant nearest planetary neighbor. Proximity to the Sun
will render the sight difficult to see however, as they rise less
than an hour before sunrise. Venus's inner partner, Mercury
, nicely visible not long ago, is now well on the other side of
the Sun, and passes superior conjunction with the Sun on Saturday
the 5th. That pretty much leaves the sky to Mars, which continues to
brighten as it plows eastward through southern Aquarius. Look for it to rise in the
southeast shortly before midnight, its bright reddish glow quite
unmistakable. Mars is on its way to historical glory. It will
begin its westerly
retrograde motion toward the end of the month, and then heads
toward closest approach on August 27, when it will be closer to us
than at any time in recorded history, a
"favorable" opposition to beat all others.
As northern summer progresses, Arcturus, the northern
hemisphere's brightest star, nightly slips slowly to the west. It
is being replaced by the north's second brightest, brilliant white
Vega, the luminary of the
constellation Lyra, the Harp that
in mythology was played by the greatest of musicians, Orpheus. To
the east of Vega is Deneb, at the
tail of Cygnus the Swan, and south
of the two lies bright Altair in
Aquila, the Eagle, the three
stars making the fine Summer
Triangle through which passes the band of the Milky Way. Far
down below Vega, close to the southern horizon for mid-northerners,
is Sagittarius, which holds the
brightest part of the Milky Way and
the center of the Galaxy, which itself contains a massive black
hole from which light cannot escape.
