Photo of the Week.Orange sunset from above the
clouds.
Astronomy news for the week starting Friday, September 19,
2014.
The Moon fades away this week in its waning
crescent phase, new Moon passed the morning of Wednesday,
September 24. The crescent goes five degrees south of
Jupiter the morning of Saturday the 20th, the two making a
fine pair. Then look for the rising crescent below the planet and
to the right of Regulus in Leo the following morning, that of
Sunday the 21st. Your last look at the ultrathin crescent will
be the morning thereafter, that of Monday, the 22nd, when it lurks
well below Leo's luminary. You'll not see our companion again
this week, not until the early twilit evening of Friday the 26th
as the new Skylights begins. The Moon goes through apogee, where it is farthest from Earth on its more or
less elliptical orbit, on Saturday the 20th.
Saturn,
still in Libra just to the east
of Zubenelgenubi, sets ever
earlier, now just half an hour or so after the end of evening
twilight. Mars, though
only slowly falling behind Earth in orbit, is not a lot better,
going down only a bit over half an hour after Saturn. East of
Saturn, the red planet is slowly approaching its namesake Antares in Scorpius (the two of similar color) and will pass only
three degrees north of the star on Saturday the 27th. West of
Saturn, Mercury makes a
particularly poor appearance in twilight even though passing its
greatest eastern elongation on Sunday the 21st. In even less of a
show, Pluto ceases
retrograde motion against the Milky
Way in Sagittarius and begins
to creep once again to the east. On the other side of the sky,
bright Jupiter is up by 3 AM, while Venus sinks ever farther into morning twilight, becoming
very hard to see.
The biggest event involves our own planet, as at 9:29 PM Central
Daylight Time (10:29 EDT, 8:29, MDT, 7:29 PDT) on Monday the 22nd
the Sun crosses the
Autumnal Equinox in Virgo, and autumn begins in the northern
hemisphere, (spring in the southern). Aside from details like the
extended disk of the Sun and
atmospheric refraction, on that date days and nights are of equal
length, the Sun rises and sets due east and west, rises at the
south pole and sets at the north pole. It's an event that can't
be missed whether you look for it or not.
After dark we now see the upswing of the ecliptic as it passes through
dim Capricornus and then Aquarius, the latter lying north of
the stellar harbinger of fall, Fomalhaut in Piscis Austrinus, the Southern Fish. North of
Scorpius and Mars find the giant pentagon than makes much of Ophiuchus, the Serpent Bearer, the
two parts of the snake, Serpens Caput and Cauda (the head and
tail), lying to either side. Above Ophiuchus is Hercules, the great Hero of ancient
times, while to the east enter the constellations of the Andromeda myth.
