Skylights featured five times on Earth Science
Picture of the Day: 1
, 2
, 3
, 4
, 5
Photo of the Week. The Moon, its nighttime side
awash with light reflected from the Earth, visits the red
supergiant Antares during the morning of January 26, 2006.
Astronomy news for the week starting Friday, February 3, 2006.
The Moon begins our week as a waxing crescent just barely short of
first
quarter, that phase reached the night of Saturday, February
4th, about the time of Moonset in North America. Curiously, though
exactly the same shape as third quarter, and covering the same
angular area of the sky, the first quarter is notably brighter than
the third
because of the third's greater coverage of dark rock that fills the
"maria," the lava-coated impact basins that make the "man in the
Moon" and other fanciful figures. The rest of the week sees it
waxing in the gibbous phase
towards next week's full.
The night of Sunday the 5th finds the Moon in a marvelous setting well
worth braving winter's cold, as it passes just to the north of Mars
(which transits the meridian high to the south as twilight draws to
a close), with the Pleiades of
Taurus just to the east of the
pairing.
Saturn
, having passed opposition with the Sun, is now already up
in the east (in Cancer) at sundown,
and is with us pretty much all night, transiting just before
midnight. As it descends in the west, watch for the rising of
bright
Jupiter (in Libra) around 1
AM. For half an hour, three bright planets are visible until Mars
finally sets. Wait then until 5 AM, when Venus
rises to bring the count back to three. Climbing ever higher in
the morning sky, Venus ceases its retrograde motion (westerly
against the background stars) on Friday the 3rd, and begins to move
easterly again (though still separating from the Sun). It will be
with us as the "morning star" much of the year, not disappearing
into twilight until late September or so. At the other end of the
scale, for that matter of the Solar System,
Neptune invisibly passes conjunction with the Sun on Monday,
February 6.
A belated happy groundhog day (Feb. 2), an actual astronomical
holiday (a "cross-quarter day") that splits the difference between
the first day of winter and that of spring.
The constellations, both ancient
and modern (the latter created mostly between the years 1600 and
1800), are rife with animals and artifacts. The Zodiac is all animalistic (Libra,
the Scales, in more ancient times being the claws of Scorpius). At 10 PM, the most
northerly of them, Gemini (the
Twins, with bright Castor and Pollux) crosses high to the south.
To the west are Taurus (the
Bull) and Aries (the Ram), while
to the east are Cancer (the Crab)
and Leo (the Lion). The arts are
not so well represented. In the north we find ancient Lyra, the Lyre, while the southern
hemisphere holds modern Sculptor
(the Sculptor's Studio) seen to the east of the star Fomalhaut, Pictor (the Easel), and stretching things a bit, Caelum (the Engraving Tool), the
latter two far south of Orion.
The
Orionid meteor shower, believed to be one of the two spawns of
Halley's
Comet (the other May's
Eta Aquarids), runs for several days, peaking on the morning of
Friday the 21st. In a dark sky, the shower is quite good (perhaps
20 a minute), but a rather bright Moon will hamper much of the
show.
The stars of the Andromeda
myth are now beautifully on stage. Look especially for the Great Square of Pegasus high to the east at
nightfall, appearing more like a giant diamond. Stretching out to
the northeast are the streams of bright stars that make the maiden
Andromeda herself, the constellation pointing the way to her
rescuer Perseus, whose star
streams stem from a prominent cluster at the center. Farther to the northeast, watch
for the rising of Capella in
Auriga, showing us that while
fall is now at hand, winter is not far behind.
