Astronomy news for the two weeks starting Friday, May 24, 2013.
We begin the fortnight with the full Moon
the night of Friday, May 24, when there will be a rather
odd eclipse, one in which the
southern edge of the Moon will barely clip the Earth's penumbral
shadow (the region of partial shadow in which just some sunlight is
cut off). The maximum effect, at 11:10 PM CDT, will be so small as to be invisible to the
eye. Take a look though, and you might spot the star Antares in Scorpius to the south of the Moon. The Moon then
spends a week in the waning gibbous,
passing third quarter on Friday the 31st,
whence it slims through crescent until
it hits new Moon on Saturday, June 8. Your last glimpse of the ultrathin crescent will be in eastern
twilight the morning of Friday the 7th. The Moon will pass perigee, where
it is closest to the Earth, just a day past full, which will bring
especially high and low tides to the
coasts.
The twilight evening sky features a wonderful alignment of planets,
a trio made of Mercury, Venus, and Jupiter. Look
early and low on the horizon during the first week of our fortnight
to see them changing places, Venus the brightest, followed by
Jupiter, then Mercury. The tightest knot will be on the evenings of
Sunday the 26th and Monday the 27th. On successive nights, Jupiter drops, while the
other two climb. Formal conjunctions take place between Mercury
and Venus the night of Friday the 24th (Mercury to the north),
Mercury and Jupiter during the day on Monday the 27th, and Venus
and Jupiter the afternoon of Tuesday the 28th. Jupiter then
quickly passes out of sight. You'll need a clear northwestern
horizon. Binoculars will help. Mercury and Venus then become
increasingly visible (Mercury on top), though even by the end of
our two-weeker both still set before twilight fully draws to a
close.
Once they are gone, we are left with lonely Saturn.
Beginning the evening in the southeastern sky well to the east of
Spica in Virgo, by the end of the month the ringed planet will
cross the meridian to the south around
10:30 PM daylight time. It then remains with us in the southwest
until just after dawn begins to light the sky.
In the early evening, the stars of spring are in full bloom, Leo a
bit west of the meridian, Virgo pretty much upon it, the Big Dipper nearly overhead as it
prepares to slip into northwestern skies, orange Arcturus brilliant
to the south of the Dipper's handle. Look later on in the
northeast for a great harbinger of the coming summer, Vega in Lyra, the star just barely fainter than Arcturus.
