Skylights featured five times on Earth Science
Picture of the Day: 1
Photo of the Week. Sunlight splashes through a prism
to reveal the visual
spectrum. Spreading from red through orange, yellow, green,
and blue, to violet, spectra (far more detailed than this one) reveal
the true natures of stars of celestial objects.
Astronomy news for the week starting Friday, October 21, 2005.
Skylights celebrates its quarter-millionth visitor.
The Moon begins the week in its waning gibbous phase as it heads to third quarter, that phase reached the night of Monday, October
24, before Moonrise in North America, after which it wanes as a
crescent. Watch as it plows through Gemini to the south of Castor and Pollux the nights of Saturday the
22nd and Sunday the 23rd (when it will be very close to Pollux).
The night of Monday the 24th finds the third quarter Moon rising
above Saturn (the
planet coming up around 12:30 AM Daylight Time). The Moon will
pass to the north of Saturn around noon the following day, and then
be to the east of the ringed planet the night of Tuesday the 25th.
The following day the Moon passes apogee,
where it is farthest from the Earth in its monthly round.
Back in the early evening, brilliant Venus climbs ever higher out of twilight,
not setting until after 8 PM Daylight Time. In the other
direction, to the east, Mars
rises brightly in twilight around 7 PM. The planet is now in
retrograde motion in eastern Aries to the west of the Hyades cluster in Taurus. We thus see a rather unusual circumstance in
that Venus (the planet just inside the Earth's orbit), Earth
itself, and Mars (the planet just outside of us) are in a rather
loose alignment, Venus setting about as Mars rises, the Earth in
the middle. Go watch!
While little Mercury, inside the orbit
of Venus, approaches its greatest eastern elongation in early
November, it still sets in bright western evening twilight and is
near-impossible to see.
Jupiter hides even more, as it
finally goes through conjunction with the Sun on Saturday the 22nd
and then becomes a morning planet. It should become visible in
morning twilight in early to mid November. Planetary action
concludes with Neptune, in Capricornus, ceasing retrograde on
Wednesday the 26th, after which it begins slowly to move back to
the east against the stellar background.
As twilight ends, Capricornus glides across the southern sky,
looking like an old-fashioned upside-down cocked hat that sits
smack on the ecliptic between Sagittarius and Aquarius. A bit to the south is a
small dim grouping that makes the modern constellation of Microscopium, the Microscope, and much
farther down, visible only from the far southern US, is modern Indus, the Indian. Down and to the
left of Capricornus find lonely first magnitude Fomalhaut, in the mouth of Piscis Austrinus, the Southern Fish,
toward which Aquarius tips his water jar.