Each month the moon passes near several bright stars of the zodiac,
sometimes occulting some of them, as is the case on March 4 with Aldebaran.
Look for these occultations: Aldebaran: March 4, 31, April 1, 27, 28 (dusk).
Pollux: March 7, 8, April 4 (dusk). Regulus: March 10, April 6, 7 (dusk).
Spica: March 14, 15 (overnight), April 11 (dusk). Antares: March 19, 20,
April 15, 16 (dawn).
A penumbral lunar eclipse will occur during the night of March 12. The Earthís shadow is made up of a dark central portion known as the umbra that is surrounded by a lighter portion known as the penumbra. During this eclipse, the moon will pass only through the penumbra and north of the umbra. Observers will notice a slight shading on the moonís southern portion. Greatest eclipse occurs at 11:30 pm EST, with 73% of the moonís diameter in the penumbral region of the Earthís shadow.
By carefully observing stars near the western horizon after sunset or near the eastern horizon before sunrise, ancients used the sky as a calendar to determine when to begin such activities as plowing, planting, and harvesting.
During April, the bright winter stars appear above the western horizon after sunset, allowing viewers to see the seasonal westward march of the stars as the ancients saw it. Try observing daily at a fixed time after sunset, say 45 minutes later. Keep track of these stars through June: Rigel, Aldebaran, Sirius, Betelgeuse, Procyon. You will notice these stars appear progressively closer to the western horizon each evening, and then finally disappear into the twilight glow. The final observation of a star, on the last date possible before its disappearance into the solar glare, is called the heliacal setting of that star. Keep a log on each of the five stars listed and try to discover for yourself the last possible date you can observe each star with the unaided eye and with binoculars only. The reason for this apparent westward motion of the stars is the Earth's orbital revolution around the sun.
Morning planets: For most of March, Venus is the only naked-eye planet
in the morning sky. Venus shines brilliantly low in the ESE an hour before
sunrise. Jupiter joins Venus in the morning sky in late March. The reappearance
of Jupiter from behind the moon on March 26 may provide the first glimpse
of the planet in the morning. Thereafter, Jupiter climbs higher in the
sky each morning, appearing to the lower left of Venus. Watch during the
first three weeks in April as Jupiter closes in on Venus. By April 23,
Jupiter passes Venus by only 0.5 degrees (about a moonís width). In reality
they are many millions of miles apart, with Jupiter the one farther behind.
They only appear close together in the sky because they lie nearly along
the same line of sight as seen from Earth. The crescent moon joins the
pair on the 23rd, making this particular Venus-Jupiter conjunction a rare
event. Don't miss it! After the 23rd, Jupiter continues to climb higher
into the sky, appearing farther away from Venus. By April 30, the two planets
will be nearly 7 degrees apart, with Jupiter to the upper right of Venus.
Mercury makes a faint appearance late in April. Binoculars will be necessary
to catch a glimpse of it hugging close to the eastern horizon far to the
lower left of Venus.
Full Mar 12 11:34 pm Apr 11 6:23 pm
Last Quarter Mar 21 2:38 am Apr 19 3:53 pm
New Mar 27 10:14 pm Apr 26 7:41 am
For current information on astronomical events, call the Skywatch Hotline
at 237-3400, then press 1-3-4 within the menuing system.
Jenny Pon is planetarium astronomer and digistar system manager for
the Henry Buhl, Jr. Planetarium & Observatory at Carnegie Science Center.
To read the map in the dark and to preserve your night vision, place a small brown paper bag over a flashlight. Hold the map in front of you and rotate it so that the edge of the horizon circle that corresponds to the direction you are facing appears at the bottom of the circle. For example, if you are facing south, rotate the map so that the edge corresponding to south appears at the bottom of the circle. The stars above this horizon on the map now match the stars you are facing in the sky.
The mapís center corresponds to your overhead point. Therefore, a star
located halfway from the edge to the center can be found in the sky about
halfway from horizon to overhead. (Saturn plotted for February 1.)
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