Photo of the Week. The September 27 lunar eclipse
with the Moon partially within the Earth's full shadow. At left is
a short exposure showing the bright uneclipsed portion of the Moon; at
right is a longer one deeper into the eclipse that
reveals the full shadow's reddish glow
from sunlight refracted and scattered by the Earth's atmosphere.
The shadow's circular outline was an early clue that the Earth is
a sphere. Courtesy of Joaquin Vieira.
Astronomy news for the two weeks starting Friday, October 23,
2015.
The next skylights will appear November 6, 2015. Daylight Savings Time
ends Sunday, November 1.
As usual we start with the Moon, which at the opening of the
fortnight is in its waxing gibbous phase
as it heads toward full Moon the morning
of Tuesday, October 27, around the time of Moonset in North
America. The evening of Monday the 26th finds it just shy of the
phase, while the following evening the Moon will have entered the
waning gibbous phase, which terminates
at last (third) quarter the morning of
Tuesday, November 3, with the Moon high in the sky near the celestial meridian. At the end we get to
see a bit of the waning crescent. The
night of Thursday the 29th, the Moon will be just to the east of
Aldebaran in Taurus. Then the morning of
Thursday the 5th look to the pre-dawn east to see the Moon not far
below Regulus in Leo and above and to the right of
bright Jupiter.
The following morning the fat crescent will pass only a couple
degrees south of the giant planet. The Moon hits perigee, where
it is closest to Earth on its monthly round, on Monday the 26th.
Venus, glorious in the pre-dawn morning sky, goes through its
greatest elongation of 46 degrees west of the Sun on Monday the
26th, and through the telescope appears in its half phase, wherein
we see half the daylight hemisphere while the other half is in
night. At the same time, Jupiter passes just a degree north of the
brilliant planet, the two making a marvelous sight. On Tuesday
the 3rd it's Mars's
turn, the red planet going under a degree north of Venus. They are
all up by 4 AM Daylight Time (3 AM Standard)
The three planets then spread
themselves out, Jupiter rising ever earlier with Mars next, while
each morning Venus rises somewhat later. Down at the bottom is
little
Mercury, which is visible in twilight only during the earlier
part of our session, if even that. By the end of the fortnight,
Jupiter rises near 2 AM. Back in the evening, Saturn sets
around twilight's end and is effectively lost until it reappears
in the morning sky as the year draws to a close.
As the stars of summer move out they are replaced by those of
autumn. In late evening, look for the Great Square of Pegasus high to the south. Below it is the Circlet of Pisces, which represents
the head of the western fish. West and a bit south of
the Circlet is another charming
asterism, the Y-shaped Water Jar
of Aquarius, which sits right on
the celestial equator, the rest of
the constellation sprawling to the
southwest and southeast. Farther down is bright and lonely Fomalhaut in Piscis Austrinus, the Southern Fish, a true announcer
of chillier days to come.
