SKYLIGHTS
Astronomy news for the week starting Friday, March 12, 1999.
The Moon wanes through its crescent phase during most of the week,
dimly illuminating the morning hours before sunrise before finally
passing through its new phase on Wednesday the 17th about noon.
Though you cannot see it, the Moon will be up, riding with the Sun
throughout that day. The Moon will then be just barely visible as
a thin crescent very low in the west in evening twilight the night
of Thursday the 18th.
The planetary show continues in the west but with fewer players.
Venus outshines everything in western evening twilight. Jupiter is
now far below it and gradually disappearing from view as the Sun
overtakes it. Venus now goes through the same act with Saturn as
it did with Jupiter, the ringed planet drawing closer to the Sun
each night, Venus still climbing upward out of twilight, the two
planets becoming ever closer and passing each other on March 20.
Of course their closeness is just an illusion as seen from here, as
Saturn is over seven times farther away than Venus.
On the other side of the sky, Mars rises ever earlier, now climbing
above the southeastern horizon around 10 PM. As Earth slowly
overtakes it, the red planet is also brightening, and is now
brighter than the star Spica, which shines in Virgo well to the
west. The planet is "stationary" this week on Thursday the 18th,
when it stops its normal easterly motion against the stellar
background and begins its long retrograde journey, the apparent
backwards westerly motion that is caused by the movement of the
speedier Earth as it prepares to swing between Mars and the Sun.
The planet will continue moving retrograde until June 5, passing
opposition with the Sun, in the middle of its "backwards" path, on
April 24 among the stars of eastern Virgo.
The extinguished Moon gives us a superb view of the sky this week.
Brilliant Sirius is to the south at nightfall and Orion to Sirius's
right as the winter constellations slowly move into twilight. Down
below Sirius is a triangle of bright stars that make the Great
Dog's hindquarters and legs. Look farther down yet to see more
bright stars just above the horizon in Puppis, the Stern of the
great ship Argo that carried Jason and his Argonauts, the ship now
separated into three parts, Puppis, Carina (the Keel), and Vela
(the Sails), all carrying many of the celestial glories of the
southern hemisphere.
