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The Night Sky of March

Dr. Wayne Wooten
Professor of Astronomy

For March 2016, the moon is last quarter on March 1, and close to Saturn and Antares in Scorpius in the morning sky. On March 7th, the waning crescent moon passes 3.4 degrees north of Venus, both rising about an hour before dawn in the SE. The Moon is new on the 9th, and passes in front of the sun for a total solar eclipse for many in Indonesia. Our turn will comeÖAugust 21, 2017; we get a similar total solar eclipse passing about 400 miles north of Pensacola about 3 PM in the afternoon sky. On March 13, we spring forward to Daylight Saving Time.

The Moon is first quarter on March 15th. The Sun crosses the equator and spring begins on the Vernal Equinox at 3:30 AM on March 20th. The Moon passes 2 degrees south of Jupiter on March 22nd, and is Full the following evening. This is the Paschal moon, following the Vernal equinox, and sets the following Sunday, March 27th, as the date for Easter this year. The waning gibbous moon passes 4 degrees north of Mars on March 28th, 10 degrees north of Antares and 3.5 degrees north of Saturn on the 29th, and is again last quarter moon on March 31st. Note that relative to Antares, the moon orbited the earth in 27.3 days, the sidereal month, but the synodic (phase month), from last quarter to next last quarter moon, took two extra days, due to our own earthís revolution around the sun during the same month.

Mercury is behind the sun and lost in its glare this month. Venus is about to do the same, and visible only briefly just before sunrise. Mars is getting brighter in the morning sky, and will reach opposition on May 22nd, rising at sunset. But this is the best month for Jupiter. The giant planet reaches opposition on March 8th, Jupiter is bright and well up in the tail of Leo by 8 PM. Small scopes reveal its four large Galilean Moons, and larger scopes show the belts and zones on the giant planetís disk, as well as the Great Red Spot, and even shadow transits as the moons pass in front of Jupiter and casting their shadows on the planetís rapidly rotating cloud tops. Finally, Saturn is still in the morning sky in Scorpius, but will come to opposition in the evening sky on June 3rd, so those who stay up late can observe it rising in the east about 11 PM in mid March, and about 10 PM at the end of the month. The rings are tilting most open at 27 degrees so Saturn will be brighter this spring than last year.

The constellation Cassiopeia makes a striking W in the NW. South of Cassiopeia is Andromedaís 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 Perseusí 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 and among the youngest known stars.

In the east are the hunterís 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, 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. Here it sits unmoving 30 degrees high in on our northern sky locally.

If you take the pointers of the Big Dipperís bowl to the 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 Lionís heart is Regulus, the "regal star". The folk wisdom that "March comes in like a Lion" probably refers to the head of Leo rising just after sunset in early March. Jupiter now sits just below the lionís tail.

If you follow the handle of the Big Dipper to the south, by 9 PM you will be able to "arc to Arcturus", the brightest star of Spring and distinctly orange in color. It color is an indication of its uniqueness. It large speed and direction through the Milky Way suggests it was not formed with our Galaxy, but is a recent capture from the Sagittarius Dwarf Galaxy, a smaller satellite galaxy now being assimilated by our huge spiral galaxy. Many of its lost stars, like Arcturus, follow a band across the sky at about a 70-degree angle to our galactic plane. Arcturus is at the tail of kite shaped Bootes, the celestrial bear driver chasing the two bears from his flocks.

By 9 PM, many more galaxies will be following as the Virgo Supercluster rises in the east. This huge cluster of over a thousand galaxies is centered about 60 million light years away. The brightest star of Virgo, Spica, lies just east of the center of the cluster, and its rise just after sunset marks the time of year for spring planting in folklore. Time to get your peas in the groundÖ. 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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