Skylights featured three times on Earth Science
Picture of the Day: 1
, 2
, 3
.
Photo of the Week.. Seen through an aircraft window,
upper and lower Sun pillars (caused by reflection from ice
crystals) pierce the Sun like a knitting needle, while a sundog to
the left (caused by refraction through the crstals) watches the
action.
Astronomy news for the week starting Friday, January 24, 2003.
The Moon starts off the week in its third
quarter, at the point where it has gone 270 degrees around the
sky from the Sun, the phase reached the morning of Saturday,
January 25th, then spends the rest of the week in its waning
crescent phase as it heads towards new on Saturday, February 1. On
the morning of Monday the 27th, the Moon will be seen to the west
of Mars,
and will pass just to the south of it during daylight hours (and
will actually occult it for people living in the South Pacific). The morning of
Tuesday the 28th then finds the Moon passing four degrees to the
south of brilliant
Venus, which, except for the Moon itself, quite dominates the
southeastern dawn sky. The Moon then heads for
Mercury, and the morning of Wednesday the 29th will be found to
the right and just up from the little planet, which will be
hovering above the horizon in bright twilight.
Venus so overwhelms the morning starry sky that it is hard to pay
attention to anything else. But take a good look at Mars, to the
west of Venus, as it passes due north of Scorpius. The morning of Friday, January 31, Mars will
pass five degrees north of its famous namesake, Antares, with which it is
occasionally confused. (The name "Antares" means "like," or "rival
of," Mars; "Ares" is the Greek name for Roman "Mars".) It's a fine
time to compare the two. Mars is still so far away from us that it
has only recently passed over to first magnitude, and is still
fainter than Antares.
The planets are now nicely distributed about the sky, and the
evening fares equally well. By 9 PM or so, Saturn
stands high in the sky moving retrograde through eastern Taurus and northwest of Zeta Tauri, while
Jupiter is high in the east, but in eastern Cancer, retrograding in the direction
toward the Beehive Cluster.
Still shy of opposition to the Sun, Jupiter rises just after
sunset, and in the dark hour just before dawn is still visible in
the west, allowing a fine comparison with much brighter Venus. In
between them all and invisible,
Neptune is in conjunction with the Sun on Thursday, the
30th.
The evening stars now center on brilliant Orion with his three-star belt and nebulous sword.
Down and to the left is the brightest star of the sky, Sirius, which twinkles madly in crisp
northern winter air. To the right winds the fainter River Eridanus. Below the Hunter rides a
stack of much fainter constellations that disappear below the
horizon for northern observers. Boxy Lepus (the Hare), just beneath Orion, is easy to find,
as is triangular Columba (the
Dove) just below Lepus. Down and to the right of Columba are two of
the sky's most obscure figures, the modern constellations of Caelum
(the Graving Tool) and Horologium
(the Clock), the latter running nearly parallel to southern
Eridanus. Farther down are Pictor,
the Easel, and brighter Dorado, the Swordfish, which contains one
of our companion galaxies, the Large
Magellanic Cloud. All these require the observer to be well
south, indeed, not far north of the equator, to see well.
