Skylights featured three times on Earth Science
Picture of the Day: 1
, 2
, 3
, 4
.
Photo of the Week.. The Moon glows softly at mid-
eclipse, in full totality, the night of October 27, 2004. Light is
refracted and scattered into the Earth's shadow by our atmosphere,
allowing the Moon to be seen in eclipse and also causing the deep
red color (for the same reason that sunsets are reddish). The Moon
passed a bit above the center of the Earth's shadow, which causes
the gradation in brightness from bottom to top. The lunar maria,
lava-filled impact basins, are readily visible.
Astronomy news for the week starting Friday, October 29, 2004.
The Moon spends the entire week in its waning crescent
phase, not reaching new until next Friday, November 12. As it
goes, it hits and occults (covers over) three planets in a row: Jupiter, Venus, and Mars, respectively
on Tuesday the 9th, again on Tuesday the 9th, and on Wednesday, the
10th. Unfortunately for the Americas, none of the events occur at
night at locations where we can see them. Jupiter's occultation at
least is "visible" in the daytime in the central and eastern US and
Canada, but only with a decent telescope. At least we had last
month's lunar eclipse to watch.
The planets themselves of course are quite visible from late
evening to the morning hours that extend into dawn. Start with Saturn, which
now rises much earlier, around 9:30 PM in eastern Gemini, nicely pointed downward to
by Castor and Pollux. After a long wait, Jupiter
and then Venus hit the stage shortly before 4 AM, both (after last
week's conjunction) still quite close together, although Jupiter is
now to the west of Venus. Almost exactly as twilight begins around
5 AM, much dimmer Mars lofts itself upward above the eastern
horizon. Between Mars and Venus, find Spica in Virgo, and to the left of Jupiter, Porrima (Gamma Virginis), which
completes the wonderful set. The Moon will make a trio above
Jupiter and Porrima the morning of Tuesday the 9th, and below Venus
the morning of Wednesday, the 10th, when it will be above Spica and
Mars in growing twilight.
Still the planetary news rolls on. Saturn, which has now moved
well into the evening, becomes stationary in its easterly voyage
against the stellar background, and turns westerly,
retrograde, on Monday, the 8th, as the Earth prepares to come
between it and the Sun. Just three days
later, on Thursday the 11th, Uranus
(in southern Aquarius), the
next planet out from Saturn, ceases retrograde, and begins normal
easterly progression. The same day, Mercury (an evening planet)
quite invisibly passes conjunction with (and to the north of) Antares.
In mid-fall we see the upswing of the Zodiac from Capricornus (the "Water Goat") through Aquarius, then past the Vernal Equinox in Pisces and into Aries. Many constellations are
known by small asterisms within them, Ursa Major by the Big
Dipper, Cassiopeia by her "W."
Aquarius -- the Water Bearer -- is best known by his Y-shaped
"Water Jar" or "Urn," from which he pours his waters into the mouth
of Piscis Austrinus, the Southern
Fish, which is epitomized by the first magnitude star Fomalhaut, "the Fish's Mouth."
Farther upstream in this "wet quarter" of watery constellations,
Pisces (the Fishes) is noted by its "Circlet," which lies due south
of the Great Square of
Pegasus.
