Astronomy news for the two weeks starting Friday, April 8,
2016.
The next skylights will appear April 22.
Over the fortnight our Moon, our only natural satellite (unless
you want to count some temporary ones that have drifted in from
the asteroid
belt), grows from a slim waxing
crescent until it hits first
quarter the night of Wednesday, April 13th, falling between the
Castor-Pollux pair in Gemini and bright Procyon of Canis Minor, Orion's
smaller hunting dog. The Moon then grows in the waxing gibbous phase until it reaches full the night of Thursday the 21st, the
exact phase taking place about midnight in North America with the
Moon to the east of Spica in Virgo. Moving slightly away from us
during our two weeks, the Moon passes apogee, where it is farthest from Earth, on Thursday
the 21st 13 hours before full, which will weaken tides at the coasts.
The night of Friday the 8th, the narrow crescent will appear up
and to the left of Mercury.
Two evenings later, on Sunday the 10th, the crescent will lie just
barely east of Aldebaran and
the Hyades cluster having
occulted the star during daylight in the late afternoon. A
telescope is needed to see the event. The night of Saturday the
16th the waxing gibbous Moon will fall right beneath the star Regulus in Leo. The following night it will glide just a couple
degrees south of much brighter Jupiter.
Mercury, visible to the west in evening dusk, is making one its
better appearances, passing greatest elongation to the east of the
Sun on Monday the 18th. This is one of those rare times when
Mercury will actually set after twilight ends. Obvious Jupiter
transits the meridian about an hour and
a half before midnight, followed about half an hour later by the
rising of Mars
, then after another half hour the rising of
Saturn. Mars is making one its great appearances north of Antares in Scorpius, the star named for its Mars-like color
("Ares" the Greek version of Mars). Mars, which makes a fine
triangle with Saturn and Antares, ends retrograde
motion on Saturday the 16th and begins retrograde motion
(westerly against the stars) in preparation for its opposition
to the Sun on May 22. In the outer part of the solar
system, Uranus
is in conjunction with the Sun on Saturday the 9th, while Pluto begins retrograde motion
northeast of the Little Milk
Dipper of Sagittarius on
Monday the 18th.
Follow the curve of the Big
Dipper's handle to orange Arcturus, the brightest star in
the northern celestial hemisphere, and
then to blue-white Spica, the
luminary of Virgo. To the south
of Spica are the eastern stars of long Hydra, the Water Serpent, and yet farther south those
of northern Centaurus, the
Centaur. If you are far enough south, below say 25 degrees south
latitude, you can catch Crux, the
Southern Cross, and to the east of it Beta then Alpha Centauri, the latter the closest star to the
Earth.
