Skylights featured five times on Earth Science
Picture of the Day: 1
, 2
, 3
, 4
, 5
Photos of the Week. From Sea to Shining Sea..., the
Atlantic sea and sky on the left, the Pacific on the right, both in March of 2006.
Astronomy news for the week starting Friday, April 7, 2006.
Read A
Minute with Jim Kaler, a brief interview on the outer bodies of
the Solar System that appears on the U of I home page.
Our Moon (the only large one in the inner Solar System) begins the
week in the waxing
gibbous phase, which leads to passage through the full
phase on Thursday April 13th during daylight hours in North
America. The night of Wednesday the 12th, the near-full Moon will
rise just before sunset, while the
following night, the just-past-full Moon will rise just after sunset. At close to the moment of
full, the Moon will occult Spica in
Virgo as seen from parts southern
Asia and Australia. From North America, the Moon will lie to the
west of Spica the night of Wednesday the 12th (between Porrima and Spica), while the
following night it will be to the east of the bright star. In the
middle of its gibbous phase, it goes through apogee,
where it is farthest from the Earth.
The only planet undergoing any kind of event is Mercury, which reaches
greatest western elongation relative to the Sun on Saturday the 8th, when
it lies 28 degrees to the west of our star and is therefore visible
in morning twilight. This Mercurian apparition is not a
particularly good one, however, as the morning ecliptic currently lies fairly
flat against the horizon, so the little planet does not get very
high before brightening dawn overtakes it. Better to admire
magnificent Venus
, which is now rising shortly before 5 AM Daylight Time.
In the evening, look for Mars, which now lies between the classical
figures of Taurus and Gemini and sets just past local
midnight. To the east of the red planet, find Saturn, which by the
end of twilight is already well past the meridian to the south. It
is so far north, however, that it does not set until 3:30 Daylight
Time. The planet lies only a few degrees to the west of the Beehive cluster in Cancer. In a dark sky (which we do
not have this week), the cluster is easily visible to the naked eye
and is a most lovely sight in binoculars. On the other side of the
sky, Jupiter (still in Libra lofts itself above the
southeastern horizon around 9:30 Daylight Time.
If the sky is dark enough to find the Beehive, you can also look
for a much larger cluster, charming Coma Berenices, which is contained within a much larger
constellation of the same name and
that lies a bit over 25 degrees south of the curve of the Big Dipper's handle. The cluster,
293 light years away (the average of its many stars), falls in the
direction perpendicular to the Milky Way, and contains the northern pole of the flat
plane of our Galaxy. In this broad direction, we see no
obscuration of the distant heavens from the Milky Way's dust
clouds, allowing us to observe the Universe of other galaxies
that flock within Coma
Berenices and neighboring Virgo.
