Photo of the Week.. The 22-degree halo around the
nearly full Moon, caused by refraction of moonlight through the
sides of hexagonal ice crystals. Note the subtle color, red on the
inside, shading to blue on the outside.
Astronomy news for the two weeks starting Friday, November 16, 2012.
The next Skylights will appear on Friday, November 30.
The Moon starts us off in its waxing
crescent phase as it heads toward first
quarter on Tuesday, November 20, during daylight hours in North
America, so it will rise that night just past the phase. It then
grows as a waxing gibbous, which ends
with full Moon on Wednesday the 28th,
also during daylight with the Moon out of sight. It thus rises that
night just after sunset and a bit into the waning gibbous, which occupies the remainder
of our fortnight.
The early evening of Friday the 16th finds the waxing crescent up
and to the left of fading Mars. Much more
visible, indeed rather spectacular, will be a close encounter
between the Moon and bright Jupiter, the two
rising the night of Wednesday the 28th with Jupiter on top (the
Moon occulting the planet as seen from southern South America).
Vastly less visible are passages between the Moon and the outer
bodies of the Solar System: Pluto on Friday
the 16th, Neptune on
Tuesday the 20th, Uranus on Friday
the 23rd. Of more interest is the Moon going through its apogee on
Wednesday the 28th just a few hours past full phase, which will
notably weaken the high and low tides at the
coasts.
Mars sets its usual half hour past sunset. On the other side of
the sky, Jupiter rises while brighter twilight is still fading (the
planet in Taurus to the
northeast of Aldebaran and the
Hyades). Just shy of opposition
to the Sun
and up nearly all night, Jupiter transits the meridian high to the south shortly before
midnight. Venus then rises
around 4:30 AM while the sky is still dark and is well up at dawn.
During most of our period, Saturn rises
just after Venus. Catching up with Venus, the two will lie within
a degree of each other the morning of Monday the 26th with Spica up and to the right and Mercury (which
goes through inferior conjunction with the Sun on Saturday the
17th) down and to the left. By the end of the week, the star and
three planets are all in a nice row, Spica, Saturn, Venus, and
Mercury, that descends down and to the left toward the horizon.
Early in the fortnight, on the morning of Saturday the 17th you
might catch a few meteors from the much weakened Leonid shower. They are the
leavings of Comet
Tempel-Tuttle, which in a 33-year period last passed closest to
the Sun in 1998.
The stars of autumn are now in full glory. Look in early evening
for the Great Square of Pegasus high to the south with the
stream of Andromeda's stars
coming off its northeastern corner. To the north of them, Cassiopeia's "W" rides high, while to
the south bright Fomalhaut
rides low above the horizon.
