The Sky of July
Dr. Wayne Wooten
Professor of Astronomy
Escambia Amateur Astronomers' Association
For July, the Moon will be new on July 3rd. The
first two weeks of July will thus find the Moon waxing in the evening sky. On July 6th, the waxing crescent moon will pass below Mars, then Saturn in evening
twilight. Next evening, the first quarter moon sits high in the sky and half-lit. The full moon occurs on July 18th, so the last two weeks find the moon waning in the
morning sky. This full moon is the Hay or Thunder moon, depending on the culture. It finds the moon about 3 degrees south of brilliant Jupiter, low in the south in
Sagittarius. Last quarter moon is on July 25th. The last two weeks of July will be good times for deep sky observing, with no moon.
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 June 30th visit the
www.skymaps.com website and download the map for July 2008; 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 as the next month begins is wonderful video exploring the July 2008 sky,
featuring many different objects, available from the Hubble Space Telescope website.
Mars moves rapidly in the west, passing just north of Mars on July 1st. Saturn is named for the god of time (Chronos in Greek) because he
moves so slowly. Much faster Mars overtakes him in the west on July 10th, with the most striking naked eye grouping happening on July 6th, with Mars midway between
Saturn on top and Regulus below. Saturn's rings are closing now, and will vanish edge-on at its 2009 equinox. It
disappears into the Sun's glare by the month's end, but Mars lingers in the west throughout August.
Overhead, the Big Dipper rides high at sunset, but falls lower in NW each evening. 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 is in the SW. Saturn and Mars lies just east of the bright star Regulus, the
heart of the King of Beasts. 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. Spike south to Spica, the hot blue star in Virgo, then curve to Corvus the Crow, a four sided grouping. It is above Corvus, in the arms of
Virgo, where our large scopes will show members of the Virgo Supercluster, a swarm of over a thousand galaxies about 50 million light years away from us.
To the east, Hercules is rising, with the nice globular cluster M-13 marked on your sky map and visible in binocs. Several other good globular
clusters are also shown and listed on the best binoc objects on the map back page.
The brightest star of the northern hemisphere, Vega (from Carl Sagan's novel and movie, 'Contact'),
rises in the NE as twilight deepens. Twice as hot as our Sun, it appears blue-white, like most bright stars. At the bottom of the parallogram of Lyra is the famed
Ring Nebula, M - 57. This photo by EAAA member John VeDepo highlights the beauty of this cosmic smoke ring, the last gasp of a dying star.
To the south, Antares rises about the same time in Scorpius. It appears reddish (its Greek name means rival of Ares or Mars to the Latins)
because it is half as hot as our yellow Sun; it is bright because it is a bloated red supergiant, big enough to swallow up our solar system all the way out to Saturn's
Just a little east of the teapot shape of Sagittarius, giant Jupiter dominates the SE sky. Any small scope will reveal what Galileo marveled
at in 1609; four large moons, all bigger or similar to ours in size, orbit it in a line along Jupiter's
equator. So get out the old scope, and focus on Jupiter for a constantly changing dance of the moons around the giant world.
Please advise visitors planning on being in the Gulf Coast area at the end of June or beginning of August of our free public gazes we hold
each year. We plan to come back out the Ft. Pickens gate again this summer, with a gaze set for June 27th with the next gaze scheduled for August 1st. We will also be
setting up Near the Performance Pavilion on August 8th and 9th. We hope you can join us at one of these events! Bring along your digital cameras to capture the rings
of Saturn, Jupiter and moons, galaxies, clusters, and other cool stuff off our live video feed from the large telescopes we use there. For more information on the
Escambia Amateur Astronomers, visit our website, or call our sponsor, Dr. Wayne Wooten at PJC at (850) 484-1152, or e-mail him at firstname.lastname@example.org. We have just issued
a CD photo gallery of the best images by EAAA members, called 'Star Shooting'.
It is available for a $10 donation to the EAAA; contact Dr. Wooten if interested.
Read past issues of the Sky at Night