Astronomy news for the two weeks starting Friday, March 18,
2011.
Skylights will next appear April 1, 2011.
Full Moon takes place on Saturday, March
19, near noon in North America such that the evenings of Friday the
18th and Saturday the 19th bracket the phase itself, Moonrise on
Friday occurring just before sunset, then on Saturday, just after.
One hour past full, the Moon goes through its perigee, when it
will be closest to Earth, the combination bringing especially high
and low
tides to the coasts. The Moon then enters the waning gibbous phase, which lasts until third quarter on Saturday the 26th, which
takes place around sunrise with the Moon near the meridian. The rest of our period is
occupied with the waning crescent, which
will make a fine sight with Venus the
mornings of Wednesday the 30th (with Venus well down and to the
left of the crescent), Thursday the 31st (Venus now down and a
bit to the right of it), and Friday, April 1 (Venus well to the right).
Earlier in the week, the night of Sunday
the 20th, look for the Moon to pass several degrees south of Saturn.
While Jupiter
is gone, we still have evening's
Mercury, which passes its greatest eastern elongation relative
to the Sun on Tuesday the
22nd and does not set until the end of twilight; Saturn, which now
rises in the east BEFORE twilight draws to a close (just northwest
of the star Spica); and morning's
Venus, which now rises as twilight BEGINS (near 5:30 AM Daylight
Time, evening twilight lasting until around 8:45 PM). Crossing the
meridian to the south around 2 AM Daylight Time, Saturn is far into
the west by the time Venus appears. In lesser news, Uranus
passes conjunction with the Sun on Monday the 21st, while Venus and
Neptune
undergo a close conjunction on Saturday the 26th.
The BIG news of course involves astronomical spring, which starts
with the passage of the Sun across the Vernal Equinox in western
Pisces at 6:21 PM CDT (7:21 EDT, 5:21 MDT, 4:21 PDT) on Sunday
the 20th, which by unusual coincidence is just over a day after
full Moon and perigee, the three all occurring within 30 hours of
one another. On the day of the equinox, the Sun will (within small
limits) rise due east, set due west, will be up for 12 hours and
down for the same. The north pole
also sees sunrise (actually a bit before equinox passage), while
the south
pole sees sunset (actually a bit after).
Bound for the equinox, the Sun entered Pisces on March 12, and will
travel there until mid-April, when it moves into Aries, rendering the classic figure
of the Ram still visible in the
west after sunset. Next up is Taurus with its Pleiades and Hyades
star clusters, which
lie to the northwest of mighty Orion.
