SKYLIGHTS
Astronomy news for the week starting Friday, February 4, 2000.
The Moon begins the week invisible and close to its new phase,
actually reached Saturday, the 5th, when it will partially eclipse
the Sun in Antarctica, the full shadow just missing the Earth. If
partial antarctic eclipses are a hobby, you can catch a similar one
on February 15, 2018. Our year 2000 is a curious one. The
geometry of solar eclipses, in which the Moon casts its shadow upon
Earth, requires at least two per year. This year there will be
four, but they are all partial! (One on December 25 will be
visible in North America). We will not see such a collection until
2011. The next total eclipse will take place on June 21, 2001, but
the shadow path will not touch North America.
As the Moon waxes through crescent toward first quarter on
Saturday, February 12, the ultra-slim crescent will be to the left
of Mercury in twilight the evening of Sunday the 6th, to the left
of Mars the night of Tuesday the 8th, and to the south of Jupiter
(high to the southwest in early evening) the night of Thursday the
10th. The same day that the Moon passes Mercury, Uranus is in
conjunction with (and far to the other side of) the Sun. While
most of the visible planets are now in the evening sky, morning is
hardly without grace, as brilliant Venus is still seen low in the
southeast in growing morning twilight.
A belated Happy Groundhog Day to all. Surprisingly, it is actually
an astronomical "holiday" of sorts, one of four "cross-quarter
days" that split the difference between the passages of the Sun
across the equinoxes and solstices (which mark the beginnings of
the seasons). Others are May Day (actually May Day eve) and
Halloween.
The Milky Way is famed for its (northern hemisphere) summertime
appearance. Now, however, is prime time to view the much fainter
winter Milky Way, which falls like a wispy lace curtain to the left
of Orion and Canis Major, the latter the constellation that holds
brilliant Sirius. Nearly overhead in early evenings, the Milky Way
is hardly visible at all in Auriga and Taurus. Our Sun is off to
the edge of our disk-shaped Galaxy, and at night we see the
combined stars of the disk as the Milky Way. In northern summer,
we look toward toward the Galaxy's center, to the thickest part,
and it is broad and bright. In winter we look away out toward the
depths of intergalactic space, and the Milky Circle is much
fainter, its faintness compounded by vast dark clouds of dusty gas
in which stars are being born.
