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The Sky of March

Dr. Wayne Wooten
Professor of Astronomy
Escambia Amateur Astronomers' Association

For March 2009, the Moon will be a waxing crescent as the month begins. First quarter moon sits high in the sky and half-lit at sunset on March 4th. We spring forward to Daylight Savings Time on Sunday, March 8th. The waxing gibbous moon passes just 5 degrees south of Saturn on March 10th, just two days after the Earth passes between Saturn and the Sun. The full moon on March 11th is before the Vernal Equinox on March 20, so Easter this year must wait still another month, until April 12th. The last quarter moon is on March 18th. The Vernal Equinox happens at 6:45 AM CDT on March 20th. The waning crescent moon passes 1.5 degrees north of Jupiter in morning twilight on March 22nd, then past Mars the next morning. New Moon is on March 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 March 1st 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.

Venus dominates the evening sky as March begins, but rapidly moves between us and the Sun and is rising before the Sun in the morning by the end of this month! On March 1st, she is still very bright, a large crescent 18% sunlit, and a disk 45 degrees of arc across, easily seen as a crescent in 10X binoculars. She is setting about two hours after the Sun. But by mid month, she sets about an hour after sunset, is now only 6% sunlit, a very beautiful and slender crescent 55 degrees of arc across. She passes about 8 degrees north of the Sun on March 27th, and her disk is now 60 percent across, the largest any planet can appear in earth's sky, but less than 1% sunlit. Between March 25-30, it may be possible to catch Venus just after sunset in evening twilight (about 6:15 PM, very low in west) then set your alarm and see her before dawn in the east (about 5:50 AM, for you early risers). By April 1st, she dominates the dawn, rising about 40 minutes before the Sun, and now appears 2% sunlit crescent, but now pulling away from the slower moving Earth, falls to only 58 degrees of arc. Throughout the rest of the spring, she will be a waxing crescent in the morning sky, but getting smaller in size daily as she leave us behind.

Mercury and Mars play tag in the morning twilight as March begins, with Mercury passing just .6 degrees south of the red planet on March 2nd. Jupiter will be the bright planet to their upper right. Jupiter dominates the morning sky, the brightest object well up in the southeast. Mars pulls farther away from slower Jupiter as March progresses, while Mercury quickly passes behind the Sun by mid month.

On March 8th, we passed between Saturn and the Sun, so Saturn rose at opposition in the east in Leo, coming up at sunset and staying up all night. As we are then closest to the ringed wonder, this is the best time to observe the most beautiful object in the sky. When viewed with a telescope, this year the rings will be even more narrow than last year. In 2010, at Saturn's equinox, the edge on rings are so narrow they will disappear with most telescopes for several weeks.

The constellation Cassiopeia makes a striking W in the NW. South of Cassiopeia is Andromeda's hero, Perseus. Between him and Cassiopeia is the fine Double Cluster, faintly visible with the naked eye and two fine binocular objects in the same field. Perseus contains the famed eclipsing binary star Algol, where the Arabs imagined the eye of the gorgon Medusa would lie. It fades to a third its normal brightness for six out of every 70 hours, as a larger but cooler orange giant covers about 80% of the smaller but hotter and thus brighter companion as seen from Earth. At Perseus' feet for the famed Pleiades cluster; they lie about 400 light years distant, and over 250 stars are members of this fine group. East of the seven sisters is the V of stars marking the face of Taurus the Bull, with bright orange Aldebaran as his eye. The V of stars is the Hyades cluster, older than the blue Pleiades, but about half their distance. Yellow Capella, a giant star the same temperature and color as our much smaller Sun, dominates the overhead sky in the northwest. It is part of the pentagon on stars making up Auriga, the Charioteer (think Ben Hur). Several nice binocular Messier open clusters are found in the winter milky way here. East of Auriga, the twins, Castor and Pollux highlight the Gemini; it is directly above us as darkness falls in early March. UWF alumni can associate the pair with Jason and the Golden Fleece legend, for they were the first two Argonauts to sign up on his crew of adventurers.

South of Gemini, Orion is the most familiar winter constellation, dominating the southern sky at dusk. The reddish supergiant Betelguese marks his eastern shoulder, while blue-white supergiant Rigel stands opposite on his west knee. Just south of the belt, hanging like a sword downward, is M-42, the Great Nebula of Orion, an outstanding binocular and telescopic stellar nursery. The bright diamond of four stars that light it up are the trapezium cluster, one of the finest sights in a telescope. EAAA member John VeDepo captures the beauty of the young stars still imbedded in their birth nebula well in the attached photo.

In the east are the hunter's two faithful companions, Canis major and minor. Procyon is the bright star in the little dog, and rises minutes before Sirius, the brightest star in the sky. Sirius dominates the SE sky as darkness falls. At 8 light years distance, Sirius is the closest star we can easily see with the naked eye from West Florida.

When Sirius is highest, along our southern horizon look for the second brightest star, Canopus, getting just above the horizon and sparkling like an exquisite diamond as the turbulent winter air twists and turns this shaft of starlight, after a trip of about 200 years!

To the northeast, a reminder of Spring come on March 19th; look for the bowl of the Big Dipper rising, with the top two stars, the pointers, giving you a line to find Polaris, the Pole Star. Look for Mizar-Alcor, a nice naked eye double star, in the bend of the big dipper's handle, rising by 7 PM at the start of March.

March comes in like a Lion, as Leo rises . If you take the pointers south, you are guided instead to the head of Leo the Lion rising in the east, looking much like the profile of the famed Sphinx. The bright star at the Lion's heart is Regulus, the 'regal star' but brighter still is Saturn, just east of Regulus.

March goes out like a lamb, not just from Easter tradition, but because Aries the Ram is setting in the west by the end of March. Many of our sayings and traditions have astronomical origins.

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