Skylights featured four times on Earth Science
Picture of the Day: 1
, 2
, 3
, 4
.
Photo of the Week.. The crescent Moon sets through
light clouds, its nighttime side awash with Earthlight.
Astronomy news for the short week starting Friday, May 9, 2003.
The Moon passes its
first quarter at the beginning of Skylights' week, Friday, May
9, well before it rises in North America. The remainder of the
week sees it grow through
gibbous to full, that phase
taking place the night of Thursday, May 15.
Usually, the full Moon passes above or below the Earth's long
shadow, but on Thursday full phase occurs as the Moon is close to
crossing the ecliptic path, and we will be witness to a fine lunar eclipse, one perfectly placed to allow
even young children to be outdoors to see. The
eclipse begins at 8:05 Central Daylight Time (add an hour for
Eastern Time, subtract one hour for Mountain, two hours for
Pacific, do nothing if you are still on EST) with an invisible
"penumbral" phase, wherein if you were on the Moon, you would see
the Earth cut off part of the Sun. The real "partial phase," when
the Moon first enters the dark terrestrial shadow, and all the
direct sunlight is cut off, begins at 9:03 PM. "
Totality," when the Moon becomes fully immersed in the shadow,
begins at 10:14, the eclipse is at maximum at 10:40, and totality
ends at 11:06. The Moon will then be seen to exit the dark shadow,
and the eclipse ends (except for the undetectable penumbral
transition) at 12:17 AM. During totality, the Moon will be faintly
illuminated by sunlight scattering and refracting through the
Earth's atmosphere, giving it a dull red color, the unpredictable
brightness depending on the state of the atmosphere, particularly
on recent volcanic activity (which makes the air murkier). The
Moon will pass to the north of the central part of the shadow, so
at the middle of the eclipse, the northern edge of the lunar disk
will be brighter than the southern edge. With the Sun entering
Taurus, the full Moon will be well to the south, the eclipsed Moon
on the Libra-Scorpius border up and to the right of the star Antares. Lunar
eclipses are great fun to watch. Use binoculars if you can to
view subtleties of color. The early stages of the eclipse will
take place in deepening twilight, while west-coasters will miss the
very beginning of it, the Moon rising already in partial eclipse.
If you miss this one, there will be another the night of Saturday, November 8.
Be sure as well to admire bright
Jupiter, which will be slipping to the west as the Moon passes
through the Earth's shadow. See if you can spot the faint smudge
of the Beehive Cluster in Cancer to the west of the brilliant
planet. Farther west, in eastern Taurus, lies Saturn
, which will be setting about the time the Moon reaches central
eclipse. Wait up for a time after the eclipse, and you get to see
Mars,
which now rises around 1:45 Daylight Time among the stars of Capricornus.
Among the largest ancient constellations of the sky is vast Argo. The huge southern figure is
divided into three smaller units, Puppis (the Stern), Carina (the Hull, which carries the sky's second-
brightest star, Canopus), and Vela (the Sails). During deepening
twilight, for northerners the last of the Sails float by just above
the southern horizon. Nearly overhead, and far more visible, sails
the Big Dipper of Ursa Major, the fainter Little Dipper now standing tall and
pointing upward, its handle ending on the North Star, Polaris.
