Photo of the Week. Jupiter shines in Gemini on January 22, 2014, with
Castor and Pollux (the lower of the two) toward
the lower left. The planet lies between Mebsuta (above and a bit left) and
Mekbuda (down and somewhat
right), Epsilon and Zeta Geminorum. See higher resolution.
Astronomy news for the week starting Friday, May 16, 2014.
The Moon fades this week in its waning
gibbous phase, which ends at third
quarter the morning of Wednesday, May 21, when the timing is
just right to see it in the near-perfect phase around the time of
sunrise in North America when the Moon is quite visible in the
daytime sky. We then get to see a couple days of the waning crescent until our week runs out.
The Moon makes no planetary passages unless you want to count the
one with distant Neptune (the planet to the south) also on Wednesday the
21st. It does, however, go through perigee on
Sunday the 18th, not that anyone could really notice, the
variation in lunar distance (and thus angular size) not all that
much, about 11 percent between perigee and apogee.
Dominating the sky for some time now, Jupiter is slowly slipping away, becoming
strictly an evening object, setting at midnight Daylight Time
still among the stars of Gemini
to the southwest of Castor and Pollux. The week's prize goes not
to Jupiter, however, but to Mars
. Since March 1 we've watched the red planet moving
retrograde, to the west against the background stars in
response to the motion of the Earth as it passes between the more
distant planet and the Sun, a month later passing north of Spica. Now well to the northwest of
Spica (and just south of the star Porrima), on Wednesday the 21st,
the same day as third quarter, the red planet reverses direction
and begins to move in its normal easterly direction and heads back
towards Spica, passing the star once again the middle of July.
It's fun to watch. Look for Mars to the south just as twilight
ends. With us all night, Mars does not set until dawn begins to
light the sky, about the time Venus ascends, the
second planet from the Sun visible only in eastern twilight.
Trekking much more slowly than Mars within the box-like structure
of Libra, Saturn can be
seen to the southeast just after dark, the ringed planet crossing
to the south around midnight. For more of a challenge, if you
have a clear horizon you might spot Mercury in western evening twilight.
Keep your eye out for a possible meteor shower the morning of Saturday the
24th, the result of a close passage to Earth of a small comet.
The Ship Argo sails ever farther
into the west, as the stars of winter are replaced in evening to
the east by the stars of summer. By late evening, Arcturus, the brightest star in
the northern hemisphere, rides high to the south, while Vega in Lyra climbs upward in the northeast. To the west of
Arcturus, below the curve of the Big Dipper's handle, look for the
lacy cloud of stars that make the Coma
Berenices cluster, while to the northeast of the star lies the
small graceful semicircle of Corona
Borealis, the Northern Crown.