Astronomy news for the week starting Friday, August 15, 2014.
Skylights will next appear on Friday, August 29.
We start our fortnight with the Moon in its waning gibbous phase, which is terminated
at third quarter the morning of Sunday,
August 17, after Moonrise in North America. It then fades away as
a waning crescent as it heads
toward new Moon on Monday the 25th. The morning of Friday the
22nd, the slimming crescent will fall between the star Procyon (down and to the right) and
the Pollux and Castor pair (up and to the left).
The following morning, that of Saturday the 23rd, the Moon will
make a glorious dawn triangle with Jupiter and Venus (Venus the
lower and brighter of the two). Then turn around and watch the
Moon pop up as a waxing crescent in the
early evening sky. Our first glimpse of it will be in western
twilight the evening of Tuesday the 26th, though it will be a lot
more obvious a day later. The Moon passes apogee, where
it is farthest from the Earth, on Sunday the 24th.
We are witness to the rare delight of two pairs of close planets,
one in the evening sky the other in the morning. Moving rapidly
eastward against the background stars, Mars crossed the
border from Virgo into Libra last Sunday the 10th, and
finally passes conjunction with much slower moving Saturn on Wednesday the
27th, the red planet four degrees to the south. Look into the
southwest as twilight draws to a close. By 10:30 PM Daylight Time
they are close to setting. But if you miss them, all you need do
is wait until morning for much brighter
Venus and
Jupiter. The two planets pass conjunction with each other the
night of Sunday the 17th. When they rise, just after the
beginning of twilight, they will be less than half a degree apart,
Jupiter to the right. The last time they performed like this was
in 2012, when they blazed forth together in the evening sky, some
taking them for UFOs and invading space aliens. While Venus sinks
out of sight into twilight, Jupiter climbs in the other direction,
the planets thus quickly separating.
As the Moon moves out of the way, we see the glory of the Milky Way, which is made of the
countless stars of the disk of our Galaxy. In mid to late
evening the Milky Way plunges down from Cygnus (which turned upside down is the Northern Cross
with Deneb at its top), through Aquila and Scutum, and into Scorpius and Sagittarius, finally disappearing below the southern
horizon. It's split into two streams by the Great Rift, a lumpy
layer of dark, cold, dusty interstellar clouds in which
stars are being born. To the northwest, the Big Dipper in Ursa
Major winds around the celestial
pole, which is closely marked by Polaris, while in the northeast,
the rising "W" of Cassiopeia
brings a sign of the coming fall.
