Photo of the Week. Standing against the sky, wind-
blown trees guard the shore.
Astronomy news for the week starting Friday, September 12,
2008.
The Moon starts us
off in its waxing gibbous phase, then hits
full early in the week on the night of
Sunday, September 14 (actually early on the morning of the 15th
shortly before moonset in North America). Our companion then
enters its waning gibbous phase as it
goes to third quarter next week on Sunday
the 21st.
The outer planets then take the stage, as the Moon winds past Neptune (in
northern Capricornus near the Aquarius border) the night of Friday
the 12th. The Moon actually occults the planet as seen from most
of North America. Not, with the Moon so bright and the planet so
dim, that one could readily see the event. Then the night of
Sunday the 14th, just an hour before full phase, the Moon passes a
few degrees north of Uranus
(practically on the Aquarius-Pisces line). These two outer planets are fascinating.
Often lumped with Jupiter and Saturn as "Jovian
planets," they are terribly different from their larger
siblings, with much lower masses and densities and made of heavier
stuff. More slowly rotating, their magnetic fields are wildly
offset from the planetary cores. Uranus then passes opposition to
the Sun the night of
Friday the 12th.
For other happenings you can't actually see, there is Venus passing
north of the star Spica on Thursday
the 18th, and on that night a conjunction between Mercury and Mars, which will be quite
out of sight above the bright twilight western horizon. Too bad,
because the quartet will make a nifty quadrilateral with Venus on
top. Venus itself, however, may be -- depending on the clarity of
your sky and the visibility of your horizon -- quite noticeable.
Back to the visible, look of course to bright Jupiter, which
occupies our southern sky as it transits the meridian to the south during mid-twilight
about the time Venus sets. The giant planet then makes something
of a transition this week as it sets at local midnight (1 AM
Daylight Time).
After the brilliance of the Scorpius-Sagittarius pair, the next constellation in
the Zodiac -- Capricornus the
(of all things) the "Water Goat" (we've all seen them) -- seems
rather disappointing. Yet sandwiched between bright Sagittarius and Aquarius, Capricornus
has its own charm, looking like an upside-down old fashioned hat,
several of its stars -- Algedi
(Alpha Cap), Dabih (Beta) and Deneb Algedi (Delta) quite well-
known. The next time you have dark skies, go take a look.
