For May the waning
crescent moon passes just south of Venus in
the dawn, both rising about 5 a.m.. The moon
is new on May 4th. The waxing crescent passes
three degrees south of Mars on May 7th. The
first quarter moon is May 11th, and the May
full moon, the Flower of Strawberry Moon, is
on May 18th. The waning gibbous moon passes
just south of Jupiter on the morning of May
20th, then even closer to Saturn on May 22nd.
The last quarter moon is on May 26th.
While the naked eye,
dark adapted by several minutes away from any
bright lights, is a wonderful instrument to
stare up into deep space, far beyond our own
Milky Way, binoculars are better for spotting
specific deep sky objects. For a detailed map
of northern hemisphere skies, about April
30th, visit the www.skymaps.com website and
download the map for the new month; it will
have a more extensive calendar, and list of
best objects for the naked eyes, binoculars,
and scopes on the back of the map. Also
available is wonderful video exploring the
sky, available from the Hubble Telescope
website at: www.hubblesite.org.
The May meteor shower
is the eta Aquariids. They will be active from
May 1st to the 28th. The Eta Aquariids are a
strong shower when viewed from the southern
tropics. From the equator northward, they
usually only produce medium rates of 10-30 per
hour just before dawn. Activity is good for a
week centered the night of maximum activity.
These are swift meteors that produce a high
percentage of persistent trains, but few
fireballs.
A meteor shower is a
celestial event in which a number of meteors
are observed to radiate, or originate, from
one point in the night sky called Radiant.
These meteors are caused by streams of cosmic
debris called meteoroids entering Earth's
atmosphere at extremely high speeds on
parallel trajectories. The Meteor Data Center
of the IAU lists over 900 suspected meteor
showers of which about 100 are well
established. To keep up to date on the latest
meteor shower visit www.amsmeteors.org.
Mercury and Venus are
both too close to Sun to be easily seen this
month. Mars is the only evening planet, faint
and distant in the west, moving from Taurus
into Gemini by midmonth. As May begins,
Jupiter rises in the SE in Ophiuchus about
midnight, and about 10 p.m. by month’s end.
Saturn is farther east in teapot of
Sagittarius, and rises about two hours later.
Both will be well placed for evening gazes by
mid June.
The winter
constellations will soon be swallowed up in
the Sun’s glare, but Orion is still visible,
with its famed Orion Nebula, M-42, seen below
the three stars marking his famed belt.
Dominating the southwest is the Dog Star,
Sirius, brightest star of the night sky. When
Sirius vanishes into the Sun’s glare in two
months, this sets the period as "Dog Days".
The brightest star in
the Northwest is Capella, distinctively yellow
in color. It is a giant star, almost exactly
the same temperature as our Sun, but about
100X more luminous. Just south of it are the
stellar twins, the Gemini, with Castor closer
to Capella, and Pollux closer to the Little
Dog Star, Procyon.
Overhead, the Big
Dipper rides high. Good scouts know to take
its leading pointers north to Polaris, the
famed Pole Star. For us, it sits 30 degrees
(our latitude) high in the north, while the
rotating earth beneath makes all the other
celestial bodies spin around it from east to
west. If you drop south from the bowl of the
Big Dipper, Leo the Lion rides high. Note the
Egyptian Sphinx is based on the shape of this
Lion in the sky.
Taking the arc in the
Dipper’s handle, we "arc" SE to bright orange
Arcturus, the brightest star of spring. Cooler
than our yellow Sun, and much poorer in heavy
elements, some believe its strange motion
reveals it to be an invading star from another
smaller galaxy, now colliding with the Milky
Way in Sagittarius in the summer sky. Moving
almost perpendicular to the plane of our Milky
Way, Arcturus was the first star in the sky
where its proper motion across the historic
sky was noted, by Edmund Halley. Just east of
Arcturus is Corona Borealis, the "northern
crown", a shapely Coronet that Miss America
would gladly don, and one of few
constellations that look like their name. The
bright star in the crown’s center is Gemma,
the Gem Star.
Spike south to Spica,
the hot blue star in Virgo, then curve to
Corvus the Crow, a four-sided grouping. Note
Jupiter now near Spica. The arms of Virgo
harbor the Virgo Supercluster of Galaxies,
with thousands of "island universe" in the
Spring sky.
To the northeast
Hercules rises, with his body looking like a
butterfly. It contains one of the sky’s
showpieces, M-13, the globular cluster faintly
visible with the naked eye. Find it with
binoculars midway on the top left wing of the
cosmic butterfly, then take a look with a
larger telescope and you will find it resolved
into thousands of stars!