Astronomy news for the week starting Friday, June 25, 2010.
Our rather quiet week begins with the Moon going through its full phase the morning of Saturday, June
26, but after Moonset, which means that we in North America do not
get to see the
lunar eclipse, which will be broadly visible across the Pacific
Ocean, including Hawaii, New Zealand, and most of Australia. You
won't miss very much, however, since the eclipse is only partial,
the Moon just clipping the southern part of the Earth's umbral
(dark) shadow and never becoming fully immersed. The remainder of
the week is spent with the Moon in its waning
gibbous phase, as third quarter is not
reached until Sunday, the Fourth of July.
As June ends, the Moon passes several degrees north of Neptune, which
is slowly drifting near the Aquarius-Capricornus
border, the planet having made only one full orbit since its
discovery in 1846. Then as July begins, the Moon passes apogee, where it
is farthest from Earth in its monthly round. In another
unnoticeable event, Mercury goes
through superior conjunction with the Sun (on the
other side of it) on Monday the 28th.
Eminently visible, however, are the other four naked-eye planets,
beginning with Venus, which
still and rightly rules the western sky in the early evening, the
planet -- by far the brightest starlike object in the sky -- still
not setting until 11 PM Daylight Time shortly after the end of
formal twilight. At the turn of the month, the planet is nicely
tucked under the Sickle of Leo. Then its up to the planet on the
other side of Earth, Mars. Fading,
moving rapidly easterly through the dimmer stars of southern Leo to
the east of Regulus, the red
planet does not set until shortly before midnight Daylight Time.
Then, not far to the east, roughly between Regulus and Virgo's Spica, find Saturn, which
slightly outshines Mars, the ringed planet just three degrees to
the north of the Autumnal
Equinox and setting about half an hour after Mars goes down.
The evenings around July 1 sees Venus, Regulus, Mars, Saturn, and
Spica all in a lovely row. As before, as Saturn sets, Jupiter
(opposite Saturn and just to the east of the Vernal Equinox in western Pisces) rises. Brighter than
the brightest star, the planet then takes over the eastern sky.
With the Moon moving out of the way, the evening presents a fine
time to be looking to the deep south. Around 11 PM, Scorpius is crossing the meridian, the sky's north-south line.
With a good horizon, you can see the bright stars of Lupus the Wolf tucked to the west
under the Scorpion's three-star head. Farther down and out of
sight for most of the U.S. (and for sure Canada) are the stars of
southern Centaurus, which includes
the closet star system to Earth, Alpha Centauri, "just" four light years away.