Astronomy news for the week starting Friday, May 3, 2013.
The Moon spends most of the week fading away in its waning crescent phase. Your last view of it
in dawn's light will be the morning of Wednesday, May 8th. It then
crosses the Sun at
new Moon the night of Thursday the 9th to produce a
solar eclipse. But North Americans need not bother, as the
eclipse will be visible only in Australia and the south Pacific.
Moreover, with the Moon near its apogee, where it
is farthest from Earth (next Monday the 13th), the angular size of
the new Moon will be too small to cover the Sun completely. The
result is an "annular eclipse" in which
at the central moment, the Moon leaves a ring, an "annulus," of
sunlight around it. While a pretty sight, an annular eclipse is of
little value to solar scientists, as the surrounding
solar corona and related effects cannot be seen: the remaining
ring of sunlight is just too bright. The only planets that the
Moon greets are
Uranus, respectively on Saturday the 4th and Monday the 6th.
For that matter, few planets are even readily visible. And as
Jupiter closes in on the Sun, we get even fewer. Bright and
visible to the northwest as twilight dims,
Jupiter now sets by 10:30 or so Daylight Time.
Venus slowly moves into evening visibility, but still sets in
bright twilight, so it will be a while before it becomes easily seen.
That leaves us pretty much with
Saturn. But that is hardly a bad thing to be left with, as the
ringed planet, second largest in the Solar System, is with us
practically all night. Having passed opposition to the Sun last
week, it is already in the sky by sunset, crosses the meridian to the south half an hour before
local midnight (12:30 AM Daylight), and sets in dawn. Find the Big Dipper practically overhead in
mid evening. Follow the curve of the handle southward to Arcturus and then to Spica. Saturn, in far western Libra, is some 15 degrees to the
east of the star.
It's a week for more meteors, the Eta Aquarids, which peak the morning of Sunday the
5th. These, along with October's Orionids, are the leavings of Halley's Comet.
But Aquarius, in the direction from
which the meteors seem to come, is so low in the southeast near
dawn, that they are only really visible in the far south.
With the Sun now heading for the Summer
Solstice in classical Gemini
(which because of precession is
just over the modern boundary into Taurus), the winter constellations are pretty much gone.
So we can now fully celebrate those of spring. In mid evening look
again for the Big Dipper high overhead, the much fainter Little Dipper (marked at the end of
its handle by Polaris) rising up
to meet it. Look directly south of the Big Dipper's handle to find
the two-star modern constellation of Canes Venatici, the Hunting Dogs, and then a bit
farther down to admire the lacy cluster that makes much
of Coma Berenices. Some 283 light
years away, the cluster represents
the hair of an ancient queen.