Photo of the Week.. In October of 2001, Venus and
Mercury visited each other, Venus the brighter of the pair.
Astronomy news for the week starting Friday, August 17, 2012.
Our glorious Moon begins the week and its phase cycle at the same
time by going through its new phase on Friday, August 17. Visible
by the evening of Sunday the 19th, it then spends the remainder of
our week as a waxing, growing, crescent.
Look for Earthlight
(sunlight reflected from the bright Earth) to light up the Moon's
nighttime side, allowing the whole disk to be visible. The
crescent show is finally over next Friday the 24th, when the Moon
passes its first quarter.
Planetary visitation just enhances the picture. Look particularly
the evening of Tuesday the 21st, when in western twilight the Moon
will make a striking box with Mars,
Saturn, and Spica. You'll need a good horizon.
Mars will be in the upper-left corner, Saturn in the upper right,
Spica in the lower right. The following evening, the Moon will
shine a bit up and to the left of the trio.
The triangle of Mars/Saturn/Spica will persist for a bit. Mars,
however, will stretch it out by rather rapidly moving to the east
relative to the other two. Look early in twilight, as the whole
affair sets by 10 PM Daylight Time. The morning presentation is
more visible.
Jupiter starts us off by rising around 12:30 AM ensconced
nicely in central Taurus to the
northeast of the Hyades and Aldebaran. Just after 2:30 AM much
brighter Venus launches
herself above the horizon in Gemini to the southwest of Castor and Pollux. Way down below,
Mercury rises just after the start of morning twilight. The
week also finds the Moon going quietly through its perigee on
Thursday the 23rd, when it is closest to the Earth, and (stretching
the week a bit) Neptune going
through opposition to the
Sun a day later. The dim planet, which can be seen with good
binoculars in western Aquarius,
recently went through its first full orbit since discovery in
1846.
By 9 PM or so, the winter
solstice, where we will find the Sun on the first day of
winter, crosses the celestial meridian
to the south roughly between the great figures of Scorpius and Sagittarius. Near here also lies the heart of the Milky Way, filled with dark clouds in
which stars are being born. By coincidence, the
winter solstice is now close (in direction) to the center of the Galaxy, which a bit over
25,000 light years away features a black hole of some
four million solar masses. Though light cannot escape from inside
it, the black hole is surrounded by a bright heated disk from which
it both draws and ejects matter taken from its surroundings.
