Skylights featured three times on Earth Science
Picture of the Day: 1
, 2
, 3
, 4
.
Photo of the Week.. A blue sky watches over a
blue-green sea.
Astronomy news for the week starting Friday, August 13, 2004.
Skylights is presented two days early this week.
We begin the week with Friday the 13th's morning sky, in which we
see the slim crescent Moon lying
just up and to the left of Saturn, both
in Gemini and to the south of Pollux. The Moon then rapidly
disappears from the nightly sky and reaches its new phase on
Sunday, August 15. It will reappear in evening twilight on Tuesday
the 17th as a still-slim
crescent, but now lying to the right of Saturn's brother planet
Jupiter. The night of
Wednesday the 18th provides better lunar viewing, as the Moon heads
for first quarter, to be passed next week.
As Jupiter sinks ever deeper into evening twilight, Saturn climbs
out of dawn, the ringed planet now rising around 3:30 AM Daylight
Time. The morning show -- for that matter really the planetary
show -- belongs to Venus
, which rises over half an hour before Saturn, and indeed as
early as it will rise this year. On Tuesday the 17th, the
brilliant planet will pass greatest western elongation, at an angle
of 46 degrees to the west of the Sun. At that time the
telescope will show it in a "half phase," wherein we see the planet
half in daylight, half in night. From here on out, the planet will
appear ever more in a fattening gibbous phase. Though Venus now
begins a slow slide down the morning sky, it will remain nicely
visible throughout the rest of the year, finally rising only as
dawn begins shortly before the year turns to 2005. In stark
contrast, Mercury and Mars, both still to
the east of the Sun, invisibly pass conjunction with each other on
Monday the 16th. In between twilight and dawn, passing to the
south around local midnight, we find the lonely outer planets, Uranus and Neptune, the
former in Aquarius, the latter
still dimly glowing among the stars of Capricornus.
As Ursa Major's Big Dipper falls silently into the
northwestern sky, Cassiopeia's "W"
rises in the northeast. Directly west of Cassiopeia is her much
dimmer husband, King Cepheus.
Farther west yet around the pole is Draco, which winds around the Little Dipper of Ursa Minor, ending in a boxy head that
with a star in Hercules makes a
prominent diamond figure. Follow a line now to the south and
arrive at the Hercules' prominent (at least in a dark sky) four-
star "Keystone." Wait until later at night to watch the rising of
Perseus, and of the lovely star
stream than makes much of Andromeda, the maiden rescued by Perseus, who rides the
winged horse Pegasus, known by
its Great Square. At the
center of it all, around which they all seem to go, is solid Polaris, which lies at the end of
the Little Dipper's handle close on to the North Celestial Pole.
