Photo of the Week. An orange sunrise lights a wintery
land.
Astronomy news for the week starting Friday, April 29,
2011.
Our Moon fades away in the morning sky during the first couple days
of the week as it wanes in the crescent
phase. After passing by the Sun as new Moon the night of
Monday, May 2, it will appear in the evening sky as a waxing crescent, where and when it will
illuminate the rest of the week. As it wanes, it will appear
several degrees above (to the northwest of) Venus the
morning of Saturday, April 30. As April turns to May, the crescent
also then passes north of nearly-invisible Uranus, Mercury, Mars, and Jupiter, all of
which lie close to the dawn horizon. Your last view of the
crescent will be the morning of Sunday, May 1. Look for it next
the evening of Wednesday the 4th as it climbs out of evening
twilight, passing through Taurus, which with its Hyades and Pleiades clusters sinks into invisibility. The lunar
view will be much better the following nights. The week also
starts with the Moon at its apogee, where it
is farthest from Earth.
It's too bad that the planetary action all takes place so close to
the bright dawn horizon, as were it all visible, it would make a
spectacular sight. Clumped within a few degrees of one another, we
find Venus, Mercury, Mars and Jupiter, with Uranus tossed in as a
bonus. (The "alignment," such as it is, has no effect on us
whatever.) As an extra, Mars passes just 0.4 degrees to the north
of Jupiter the morning of Sunday the 1st. The only one readily
visible is bright Venus, and that requires a good horizon and good
timing, the planet not rising until mid-way into morning twilight.
That leaves us with Saturn. Not part of the
family gathering, as the sky darkens the ringed planet is well up
in the east (still to the northwest of Spica), and now appears to
the south crossing the meridian around
11 PM Daylight Time and not setting until morning's early
light.
May is ushered in with yet another astronomical holiday, May Day,
the first of May (rather May Day eve), which marks the midway point
between the beginnings of spring and summer and bears the same
relation to the seasons as Groundhog Day does to winter and spring.
So enjoy the days of warmth to come.
The debris of Halley's Comet
hits us this week as the Eta Aquarid meteor shower, which emanates from Aquarius and peaks the morning of
Friday the 6th before dawn. Unfortunately, it is a southern
affair, those in mid-to northern North America not seeing
much.
As the Sun moves to the north along its ecliptic path, the evening Zodiac slips ever more to the
south. At 9 PM, Leo now rides high
to the south, followed by Virgo,
which is graced by Saturn and Spica. Stay up past midnight, and Libra starts to make its passage.
To southeast of it and to the southwest of Spica, lies the tail of
Hydra, the Water Serpent, whose
scary head is just to the east of Procyon in Canis Minor.
