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The Sky This Week, 2011 February 15 - 22

Changing of the Guard
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Lunar Crater Clavius, imaged 2011 FEB 13
20-cm (8-inch) f/10 Schmidt-Cassegrain telescope
with 1.6X Barlow lens


The Moon beams down from a perch high up among the stars of Gemini as the week opens, then drifts southeastward to join the rising stars of spring. Full Moon occurs on the 18th at 3:36 am Eastern Standard Time. February’s Full Moon is variously known as the Snow Moon, Hunger Moon, or Wolf Moon, each traditional name being indicative of the harshness of the season. Luna lies between the Twin stars of Gemini, Castor and Pollux, and the bright star Procyon on the evening of the 15th. On the 17th her nearly-full visage shares the sky with the bright star Regulus, heart of Leo, the Lion. Late-night skywatchers can watch the waning gibbous Moon rise in the company of Saturn late on the evening of the 20th.

The bright Moon washes out most of the fainter stars in even the darkest skies for most of the week, but you can still get out and enjoy some of the beauty that the season’s nighttime vistas. The Moon’s high declination bathes the landscape in silvery light, and if your surrounding terrain is still snow-covered you should have no trouble navigating by her ghostly glow. The starkness of the landscape, ravaged by wither’s storms, seems to soften in the pale sheen, reminding us that the year’s most harsh season will soon be replaced by one in bloom. Even winter’s bright stars tell us that spring is fast approaching. Where Orion and his cohorts seemed to occupy center-stage in the sky all night long they are now dipping toward the western horizon as midnight approaches, replaced by the rising constellations of spring.

Bright Jupiter, which has held sway over the evening sky since late last summer, is finally losing his place of prominence as the Sun relentlessly chases him down. Old Jove is still easy to spot in the early evening sky of the twilight hours, but he’s now visible for a short time afterward. He now sets at around 8:45 pm, and any attempt to catch a good view of him through the telescope has to be made when he first pops out of the twilight sky. By the time full darkness falls the planet is too low to observe without peering through the denser and more turbulent air currents above the horizon. In just over six weeks he’ll be gone, but he’ll return to prominence well before the end of the year.

Saturn rises in the company of the Moon on the night of the 20th and should be easy to find on the ensuing nights. The ringed planet occupies a relatively star-poor region of the sky in the sprawling constellation of Virgo. His only stellar competition comes from the star Spica, which has a distinctive blue tint that easily distinguishes the star from the golden hue of the planet. If you let your gaze follow the horizon toward the north, you’ll also see the rising bright star Arcturus, which to me is always a sure sign of spring. Saturn is well-placed for telescopic viewing before midnight and should offer a fine view to compensate for the loss of Jupiter.

Bright Venus may be spotted over the southeast horizon in the hours before dawn. She rises about an hour before the beginning of morning twilight and remains visible until a few minutes before the Sun breaks into view. She is gradually inching her way toward solar conjunction, but that won’t happen until well into the summer months. Early risers can count on her as a companion for quite awhile to come.

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