SKYLIGHTS
Astronomy news for the week starting Friday, April 7, 2000.
The Moon moves from waxing to waning gibbous during the week,
passing through full on Tuesday the 18th just about noon in the
central western hemisphere. The Moon will therefore be just short
of full the night of Monday the 17th and just past full phase as it
rises a bit after sundown the night of the 18th. That night look
for the first magnitude star Spica to the west of the Moon.
The planets move deeper into twilight (Jupiter, Saturn and Mars in
the evening, Mercury and Venus in the morning) as they rendezvous
for their close clumping in early May. Since Mars is so close to
the Earth, and moves so fast, it falls behind us only very slowly,
whereas slower moving Jupiter and Saturn depart quickly to the
west. Last week, Mars passed Jupiter, and now it is Saturn's turn.
Mars and Jupiter will be in conjunction the night of Sunday, the
16th, the red planet two degrees to the north of the Saturn.
Binoculars will help a great deal.
Spica (in Virgo), passed by the Moon on Tuesday, the 18th, is one
of the five first magnitude stars of the Zodiac. Next in line, to
the east, rising later in the evening, is reddish Antares in
Scorpius, which is the southernmost of the set and lies just south
of the ecliptic, the apparent path of the Sun. Continuing east,
Sagittarius just misses first magnitude, and then we pass through
four more constellations before arriving at the brightest of the
Zodiac's first magnitude stars, Aldebaran in Taurus, which is now
being lost to sunlight in western evenings. Moving on, we then
pass the most northerly of the set in Gemini, orange Pollux
(closely paired with the sky's brightest second magnitude star,
Castor). From there we plunge back south to Regulus in Leo, the
dimmest of the five, and next to last in the first magnitude rank
(the last Adhara in Canis Major, which just barely passes the
test).
Among all first magnitude stars, the brightest, Sirius
(coincidentally also in Canis Major), is still very visible in the
evening's southwestern sky. The most northerly, Auriga's Capella,
shines high in the evening's northwest (at least for those in the
mid-northern hemisphere), while the most southerly, Acrux in the
Southern Cross, lies far south of Arcturus (the brightest star of
the northern hemisphere), and for northerners well below the
southern horizon.
