Astronomy news for the week starting Friday, May 25, 2012.
Our Moon begins our week in a fat crescent phase as it approaches its first quarter on Monday, May 28. North
Americans will see it rising in the afternoon daytime sky. In the
following days, it will then grow into the waxing
gibbous phase, full Moon not
achieved until rather well into next week, when it will undergo an
eclipse seen throughout most of the Pacific basin and western
and central US and Canada. On the morning of Tuesday the 29th, the
Moon will pass seven degrees to the south of Mars (the wide
angle due largely to lunar orbital tilt). On the previous evening
(Monday the 28th), the lunar disk will be a bit to the southwest of
the planet. Then on the night of Thursday the 31st, we will find
the Moon gliding about the same angle to the south of Saturn. Since
Saturn is north (and a bit east) of Spica, the three (going north, the
Moon, Spica, Saturn) will lie in a nice row, the Moon rather close
to the star, making it a bit difficult to see.
Venus, which
has been gloriously with us during the whole of 2012 (and for some
time before), is now effectively gone, at the beginning of our week
already setting in late twilight. It is preparing to sweep across
the face of the Sun in a rare transit
that for North Americans will start late in the afternoon on
Tuesday, June 5, at 5:05 PM CDT, and for the contiguous US and most
of Canada will run until sunset. Optical aid is needed, and since
the Sun is so bright,
so is a professionally-made filter. Projection of the image works
well too.
This week, it is Mercury's turn,
as the planet goes through superior conjunction with the Sun on
Sunday the 27th, the planet in back of the Sun, the event, such as
it is, quit invisible. It will thereafter pop up in the early
evening sky. The night then belongs to Mars and Saturn, the two
nicely visible at the same time. The western one of the two, Mars
is now moving easterly to the south of the eastern hindquarters of
classical Leo well to the southeast
of Regulus heading for Virgo (and in mid-August for
Saturn). Well into the western sky at dusk, the red planet now
sets around 2 AM. Transiting the meridian in late twilight, Saturn follows
Mars to the horizon by about an hour and a half. Regulus, Mars,
Spica and Saturn make for a fine evening's viewing.
If you are far enough south (meaning here mostly Hawaii), this is
the season for Crux, the Southern
Cross. However, northerners can still admire some of the bright
stars of Centaurus (the Centaur)
that more or less wrap around the Cross to the north. Just get a clear horizon
and look well to the south of Spica past the dim tail of Hydra, the Water Serpent.
