Skylights featured three times on Earth Science
Picture of the Day: 1
, 2
, 3
.
Photo of the Week.. Checkerboard Sky.
Astronomy news for the week starting Friday, February 7, 2003.
The Moon
dominates the evening sky this week, as it changes from a waxing crescent
to a waxing
gibbous, the transition made at the first
quarter, which takes place on Sunday, February 9, the Moon to
the west of the classic figure of Taurus. As our companion rumbles along its orbit, it
will pass three degrees north of Saturn the night of Tuesday, the 11th,
the two making a fine sight in eastern Taurus.
As February begins, the ringed planet stands high to the south (for
those in mid-northern latitudes) around 8:30 PM, and is now setting
in the northwest just as morning twilight begins. Jupiter,
some 60 degrees to the east of Saturn, shines among the dim stars
of Cancer. Having just passed
opposition to the Sun, it rises very close to sunset and crosses
the meridian to the south around midnight. Look for the planet low
in the east as evening twilight draws to a close. As bright as it
is, however, Jupiter pales in comparison to Venus,
which hangs brilliantly to the southeast at dawn, with reddish Mars
still up and to the right of it above the striking figure of Scorpius. The color contrast between
the two planets is readily seen. Though Mars is still moving
easterly, they are nevertheless slowly drawing apart, the pair that
flank the Earth
making planetary motion obvious.
Great Orion now dominates the
stellar sky, standing imposingly to the south in mid-evening, his
three-star Belt (the ancient Arabs' "string of pearls") one of the
most striking of celestial asterisms. The red supergiant Betelgeuse is up and to the left,
while in contrast the bluish supergiant Rigel is down and to the right.
Hanging from the belt is the giant hunter's Sword, which contains
the magnificent Orion Nebula.
A small telescope, even large binoculars, will show swirls of
interstellar gas and dust. Lit by a quartet of extremely young
stars in front of it, and some 1500 light years away, the nebula is
a blister on the front side of a huge dark dusty cloud in which
active star formation is still going on. The bright blue stars of
Orion are in fact part of a recognized "association," most of them
born from the same complex of parent birth clouds. The figure of
Scorpius, opposite Orion in the morning sky, is structured in much
the same way. Orion is part of "Gould's Belt," named after B. A. Gould, who noted that many of the sky's bright
blue stars fall in a circle tilted to the Milky Way,
which runs just to the east of Orion and down through Orion's
larger Hunting Dog, Canis Major,
the constellation containing the brightest star of the sky, Sirius. Immediately to the east of
upper Orion is the Smaller Dog, Canis
Minor, with bright Procyon,
it, Betelgeuse, and Sirius making the famed Winter Triangle.
