Photo of the Week.. The bright stars of southern
Scorpius preside over the Texas
landscape. The bright collection to upper left is the cluster
Messier 7. Between Scorpius and the horizon lies the
constellation Ara, the Altar, whose
southern stars are highly reddened by the thick Earth's atmosphere.
Photo by Chris Grohusko.
Astronomy news for the week starting Friday, November 22, 2002.
Our Moon wanes through its gibbous phase the early part of the
week, and passes its third
quarter on Wednesday, November 27, within the confines of the
constellation Leo just northeast of
Regulus, when it rises around 11 PM,
rendering it easily visible during the morning daylight hours.
The night of Monday, the 25th, the Moon will pass four degrees to
the north of Jupiter
around midnight, the giant planet hovering between Cancer and Leo and rising around 10
PM.
Saturn is better placed for evening viewing, coming up above the
horizon between Taurus and Gemini just after 6 PM. For a real
show, you have to wait until morning, when Venus
lofts herself above the southeastern horizon, the planet now
terribly obvious and rising just after 4 AM. A telescope will show
Venus to be a thin crescent, as the planet is still more or less
between us and the Sun, which allows us only a small view of its
daytime side. Even higher-power binoculars will reveal the
crescent, much as they will show Jupiter's four large
moons, Io, Europa, Ganymede, and Callisto, the latter two
roughly the size of the planet Mercury.
Venus is so very bright that in a dark site it will cast shadows
and is visible in full daylight, so long as the sky is brilliantly
blue and clear. Surprisingly, so is Jupiter, but just marginally,
and only under the very best of conditions with a fine pair of
eyes.
As the Earth
goes around the Sun, the Sun appears to trek its ecliptic path and pass
through the famed constellations of the Zodiac.
They are of very different angular sizes, and the Sun appears
projected against them for quite different time periods. The Sun
takes well over a month to span Virgo, while it is in Scorpius for a mere 6 days, during this week from
Saturday the 23rd to Friday the 29th, rendering the constellation
and
its surroundings quite invisible. Though you cannot see them, Sagittarius will be to the left of the
Sun, Libra to the right. Far to
the
south of the Sun will be one of the most southerly of all the
ancient constellations, Ara, the
Altar, upon which Scorpius seems to rest. Oddly, the Sun is within
the modern confines of a non-Zodiacal constellation far longer than
it is in Scorpius, as it traverses Ophiuchus between November 29 and December 18.
Scorpius has now been replaced at night by great Orion, whose brilliant stars are now
rising in mid-evening, with Canis
Major and wonderful sparkling Sirius soon to follow.
