Volume XVII, Issue 22 # May 28 - June 3, 2009

Sky Watch
by J. Alex Knoll

Follow the Moon

Wax your nights away

The moon waxes through the spring constellations of the zodiac this week, providing an easy guide to the southern sky.

As the sun sets Thursday around 8:20, the crescent moon appears high in the west. Twenty degrees to the moon’s right shine Pollux and Castor, the Gemini twins, while Regulus, the heart of Leo the lion, shines the same distance to the moon’s left. Compared to these three first-magnitude stars and their clear constellations, you could easily miss Cancer, the crab, between them. But on this night, the moon is smack-dab in the middle of it. The crab boasts no first-magnitude stars, but it does host the Beehive Cluster, M44. With unaided eyes, look for a smudge of light a few degrees to the upper right of the moon. Zero in with a small telescope or even a pair of binoculars, and you’ll see, as did Galileo, “a mass of more than 40 small stars.” Today, we know that this distant cluster is abuzz with hundreds of stars.

Sunset Friday finds the moon farther to the east, now less than 10 degrees to the lower right of blue-white Regulus. Named by Copernicus, this kingly star lies in the handle of the Sickle of Leo, which looks like an inverted question mark outlining the head and chest of the celestial lion.

Come Saturday, the moon has crept to the southwest of Regulus and is flanked to the northeast by Saturn. With an outstretched arm, your closed fist covers roughly 10 degrees, more than enough tonight to obscure both the moon and Regulus or the moon and Saturn. Sunday’s first-quarter moon shines 10 degrees below Saturn.

With the new week, the waxing gibbous moon edges toward Virgo. Tuesday it is little more than five degrees to the right of the constellation’s alpha star Spica, and Wednesday it is still less than 10 degrees to Spica’s left.

Illustration: © Copyright 1925 M.C. Escher/Cordon Art-Baarn-Holland; Graphics: © Copyright 2009 Pacific Publishers. Reprinted by permission from the Tidelog graphic almanac. Bound copies of the annual Tidelog for Chesapeake Bay are $14.95 ppd. from Pacific Publishers, Box 480, Bolinas, CA 94924. Phone 415-868-2909. Weather affects tides. This information is believed to be reliable but no guarantee of accuracy is made by Bay Weekly or Pacific Publishers. The actual layout of Tidelog differs from that used in Bay Weekly. Tidelog graphics are repositioned to reflect Bay Weekly’s distribution cycle.Tides are based on National Oceanic and Atmospheric Administration and are positioned to coincide with high and low tides of Tidelog.