Photo of the Week. A diffraction corona, caused by
the mutual interference of light waves as they pass through light
clouds and dramatically highlighted by thicker ones, surrounds the
full Moon. See the corona around the crescent.
Astronomy news for the two weeks starting Friday, January 16,
2015.
Back to fortnights for a bit: thanks for your patience. The next
skylights will appear January 30, 2016.
We start with the Moon late in its waning crescent phase, which
ends at new Moon on the morning of Tuesday, January 20. The
morning of Saturday the 17th, the rising crescent will appear well
to the left of Antares in Scorpius and down and to the
left of Saturn. From new Moon we look to
evening western twilight to see the waxing
crescent climb toward first
quarter, which takes place on the night of Monday the 26th
around the time of moonset in North America. It then enters the
waxing gibbous phase as it plows toward
full Moon on February 3. The night
of Wednesday the 21st the Moon passes well north of Venus, then the next night north of
Mars. After the quarter, the Moon invades Taurus. The night of Wednesday
the 28th, find it to the west of the Hyades and Aldebaran and to the south of the
Pleiades. The following
evening it will switch to the other side of the bright orange
star. The Moon passes perigee, where it is closest to Earth, on
Wednesday the 21st.
In the west, Venus is getting ever higher, and as our fortnight
opens sets just after the end of evening twilight. It will make a
glorious sight this spring and early summer. Early in our
extended period, Venus hovers near fainter Mercury, the little planet
quickly disappearing then passing inferior conjunction with the
Sun on Friday the 30th. The show really belongs to Jupiter, which rises (still in western Leo to the west of Regulus) about as Venus sets and
twilight ends, and is with us all night, crossing the meridian high to the south shortly past
midnight. Not long after (about 3:30 AM at the start of our
session, 2:30 AM at the end) we get to see Jupiter's brother
planet Saturn loft itself over the southeastern
horizon just off the tip of the head of Scorpius and nicely above
Antares. Back in the west, Mars, now deep in Aquarius approaching Pisces, reliably sets at 8 PM. On Monday the 19th,
the red planet will pass a mere two-tenths of a degree south of
much fainter Neptune, making
for a fine telescopic event.
With good fortune, if it's bright enough, you might get to see Comet Lovejoy as
it climbs west of Taurus and the Pleiades then southwest of Perseus, between it and Triangulum (the Triangle). Lovejoy
is clearly a drop-in from the distant Oort Cloud of icy comets that were ejected by the giant
planets during the formation of the solar system. As such it is
pretty unpredictable. If you can't see it, try scanning around
with binoculars.
Perseus and Auriga stand high
nearly overhead in mid evening, the two making a nifty triangle
with Taurus to the south, and Orion even farther below, the winter skies filling
with brilliant stars. Fainter, Eridanus, the River, winds to the southwest of Orion then for
northerners below the horizon where it ends in beautiful bluish Achernar.
