SKYLIGHTS
Astronomy news for the week starting Friday, April 21, 2000.
Find stars that have orbiting planets! The "Planet Project" has
been added to the Stars Website.
The gibbous Moon wanes the early part of the week, passing third
quarter on Wednesday, the 26th near noon, about the time it sets in
North America. The day before the quarter, the Moon passes a bit
south of Neptune, the day after to the south of Uranus, both of
these distant planets seen against the stars of Capricornus. Two
days before the quarter, the Moon passes apogee, the point where it
is farthest from the Earth.
The classical -- ancient -- planets (Mercury, Venus, Mars, Jupiter,
and Saturn) draw ever closer for their get-together in early May.
As prelude, Mercury is in close conjunction with Venus the morning
of Friday, the 28th, the two a third of a degree apart. Don't get
up for it, however, as they are hardly visible, both far to the
other side of the Sun and rising only in growing twilight. Since
the middle of March, Mercury has actually been higher in the sky
than Venus; now it returns to its more lowly position. The giant
planets, Jupiter and Saturn, have also now reversed their positions
relative to Mars. Now setting earlier in twilight, they are
getting difficult to see.
This planetary gathering, of course, is only a curiosity, and has
no physical effect. Were it not for the Sun spoiling the show, it
would, however, be a delight to see. Rather curiously too, the
outer planets do not join the convention, Uranus, Neptune, and
Pluto strung out along the ecliptic well to the west of the
Sun.
Between Gemini in the west and great Leo, with its prominent Sickle
ending in Regulus, lies the dim constellation Cancer, recognizable
mostly by the fuzzy-appearing Beehive Cluster. Directly south of
it is a faint circlet of stars that represents the head of Hydra,
the Water Serpent, the longest constellation in the sky. Southwest
of Regulus is Alphard at the Serpent's heart. To the southeast of
Regulus is the bright star Spica, below which the Serpent continues
to wind. On Hydra's back, to the west to Spica, is Corvus, the
Crow (its top two stars Spica's "pointers"), and to the west of
Corvus one of the dimmest of all classical constellations, Crater,
the Cup, something of a challenge even in a dark sky.
As midnight draws close, we look outward south of the Big Dipper
perpendicular to the disk of our Galaxy, the Milky Way practically
nowhere in sight. The view is so clear of the Milky Way's dust
that we can see huge numbers of other galaxies far into the depths
of space.
